Interesting. But would there still be some lag time with that passive shield?Smaller material volume means less HEAT buildup (and retension) as well as less material surface area acting like car radiator heating the incoming air. The more material the quicker the sun heat is captured and thus quicker to transfer more heat (larger radiator) into the incoming air; less material is opposite effect.
Smaller material volume means less HEAT buildup (and retension) as well as less material surface area acting like car radiator heating the incoming air. The more material the quicker the sun heat is captured and thus quicker to transfer more heat (larger radiator) into the incoming air; less material is opposite effect.
OK, I just snagged the last 7714 in stock from Ryan. Gonna run this as my passive shield backup. I'll put a wet 31 sensor in there and see how temps perform. I will be SHOCKED if this thing can run neck and neck with my FARS with the AC fan inside long term.
Of course your local ASOS, that you're comparing to, is pumping the air through the sensor chamber too so the FARS really shouldn't be considered the root of the problem. It still goes back to the Davis sensor. If you're getting readings you like with the passive shield though then I guess the workaround works for you with your setup. It would still be nice to get the readings to jive with the FARS installed.
True. Of course the Vaisala sensor is artificially heated to completely prevent condensation from forming on it. Then they have their algorithms to produce a fairly accurate Td. The whole topic has my brain spinning in circles and my migraine doesn't help.Of course your local ASOS, that you're comparing to, is pumping the air through the sensor chamber too so the FARS really shouldn't be considered the root of the problem. It still goes back to the Davis sensor. If you're getting readings you like with the passive shield though then I guess the workaround works for you with your setup. It would still be nice to get the readings to jive with the FARS installed.
If the "problem" you're referring to is humidity measurement, the airport does not aspirate their humidity sensor. It's only minimally shielded from the elements, not contained within a standard radiation shield.
Randy can correct me if I'm wrong, but I think he's just trying to establish temperature accuracy before tearing down his existing aspirated shields and replacing them with the 7714.
EDIT: I should probably clarify that it's the dew point sensor that is minimally shielded and humidity is derived from that.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
My problem with it is it's designed for a probe sensor and is completely open at the bottom letting in reflected radiation. I'm thinking of snow albedo and longwave radiation at night, in particular. Plus, isn't it something like $500 just for the shield?
Randy, do you visit Dr Steve Dimse's findU weather site? There, you can overlay selected local sites (yes, more than one) over your plots. For example, here's my DW6988 (blue) overlaid with local Marana airport KVAQ (purple):
https://weather.gladstonefamily.net/qchart/D6988?date=20180727&addnl=KAVQ&Add+to+charts=Add+to+charts&.cgifields=addnl (https://weather.gladstonefamily.net/qchart/D6988?date=20180727&addnl=KAVQ&Add+to+charts=Add+to+charts&.cgifields=addnl)
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
Edit: Forgot to add you will have to do some engineering to get the Davis sensor to fit.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
My problem with it is it's designed for a probe sensor and is completely open at the bottom letting in reflected radiation. I'm thinking of snow albedo and longwave radiation at night, in particular. Plus, isn't it something like $500 just for the shield?
The Davis #07714 has a closed bottom shield plate and was only $54.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
Edit: Forgot to add you will have to do some engineering to get the Davis sensor to fit.
Can you get the SHT31 inside? I was going to be involved with testing these but they never got back after I gave them all information.
I made the mistake of posting a thread here and had a few negative post about persons with no interest in a passive shield and never heard back from them again.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
Edit: Forgot to add you will have to do some engineering to get the Davis sensor to fit.
Can you get the SHT31 inside? I was going to be involved with testing these but they never got back after I gave them all information.
I made the mistake of posting a thread here and had a few negative post about persons with no interest in a passive shield and never heard back from them again.
They quietly pulled their development of their VP2 compatible shield. They were trying to use a probe and couldn't get it connected to the SIM. My guess is Davis won't sell their sensors to a competitor so they tried their own solution and couldn't get it to work.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
My problem with it is it's designed for a probe sensor and is completely open at the bottom letting in reflected radiation. I'm thinking of snow albedo and longwave radiation at night, in particular. Plus, isn't it something like $500 just for the shield?
The relative humidity sensor shall be
thermally isolated in a motor aspirat
ed radiation shield to accurately
measure the atmospheric
dew point temperature.
Has anyone else tested one of these?
https://www.baranidesign.com/meteoshield-professional/
I've had mine in for about three days and happy with the results. Stats from MADIS have held about the same compared to ASOS station close to me and the last two days have been mostly sunny and fairly light wind. The shield is expensive for a passive and definitely more than the 7714. It's supposedly designed to protect the sensor from contamination in the way airflow is directed inside the chamber.
Edit: Forgot to add you will have to do some engineering to get the Davis sensor to fit.
Can you get the SHT31 inside? I was going to be involved with testing these but they never got back after I gave them all information.
I made the mistake of posting a thread here and had a few negative post about persons with no interest in a passive shield and never heard back from them again.
They quietly pulled their development of their VP2 compatible shield. They were trying to use a probe and couldn't get it connected to the SIM. My guess is Davis won't sell their sensors to a competitor so they tried their own solution and couldn't get it to work.
Here, I took a couple photos of the ASOS DTS1 sensor/shield. The weeds are gone now but my allergies aren't :lol:
My problem with it is it's designed for a probe sensor and is completely open at the bottom letting in reflected radiation. I'm thinking of snow albedo and longwave radiation at night, in particular. Plus, isn't it something like $500 just for the shield?
The only opening on the bottom is for a probe type opening. Like I said you have to do some engineering to get a Davis to work. This is actually kind of a double shield with the outer being white and the inner being black to protect against longwave radiation loss at nigh
Seems like I saw a test somewhere where they compared this shield over a snowpack and it outperformed some FARS units. Will have to see if I can find it though.
As far as pricing I think I got it for around $250.
Here, I took a couple photos of the ASOS DTS1 sensor/shield. The weeds are gone now but my allergies aren't :lol:
OK, just to clarify, this is for an ASOS system? But, apparently, the more modern AWOS's, or some subset of them, aspirate the humidity sensor, at least according to the documentation.
Yes, they do. I've worked on the AWOS III-PT. Unless they have done something custom it doesn't use separate sensors for temperature and humidity. It uses a combination 5190-F temperature/humidity sensor inside the 8190 MARS.
Emailed Ryan about being out of the 7714 he said business has been steady for long time, especially in Canada hard to keep them in stock. Backordered again.Have you tried contacting Bob Ingham at Rainman Weather?
Have you tried contacting Bob Ingham at Rainman Weather?
Was hosing off my ISS to get some of the dust off of it and got water into the chamber and killed my 67 CFM fan. Ordered another but will take faaar too long to get here, so went and bought one that's "only" 40 CFM from down the street, cause this boy ain't doin' without a fan. Thing's really quiet compared to the other, Ill probably just leave this weaker one in.
GL to all the passive efforts!
I see zero difference, nor did I expect to. 67, although overkill, worked just fine, so will 40, even if it's overkill too. I'll take it.Was hosing off my ISS to get some of the dust off of it and got water into the chamber and killed my 67 CFM fan. Ordered another but will take faaar too long to get here, so went and bought one that's "only" 40 CFM from down the street, cause this boy ain't doin' without a fan. Thing's really quiet compared to the other, Ill probably just leave this weaker one in.
GL to all the passive efforts!
If only you had two ISS's to compare to. I wonder how much temp difference there might be between using a 67 and 40cfm fan, if any.
First full day lots of clouds even a thunderstorm with passive once again slightly cooler vs FARS. Couple things morning warm up showed some lag vs FARS red arrow and the fars was more jagged with dew point. I hate that when we are in high heat index area and it spikes.Looks like it's right in line with the FARS with just a slower response. I see no problem with the jagged dewpoint graph. To each his own though. Pretty sweet performance by the passive though...clouds or not. What did your winds average?
First full day lots of clouds even a thunderstorm with passive once again slightly cooler vs FARS. Couple things morning warm up showed some lag vs FARS red arrow and the fars was more jagged with dew point. I hate that when we are in high heat index area and it spikes.Looks like it's right in line with the FARS with just a slower response. I see no problem with the jagged dewpoint graph. To each his own though. Pretty sweet performance by the passive though...clouds or not. What did your winds average?
My results with the 7714 compared side by side to the stock 24hr FARS are pretty much right on with ValentineWeather. Maybe it’s the latitude? I’m a FARS fanatic too and almost didn’t want to believe it as it seemed counterintuitive. I went with the 7714 recently because I just moved and my yard presents unique circumstances. The results of the side by side made it easier to swallow.
I haven't played with black yet but i used Rust. flat white paint made for plastic and uv resistant. I am not sure how you tell if black will be absorbent or not, just thought black would absorb being black and all lol. Need a paint guru to chime in here. :???:Not a paint guru, so I'll just state what's probably more or less obvious. If you paint the inside of your shield you better give the paint plenty of time to dry before putting the sensor in, as there seems to already be a lot of concern about contamination. Also I would be a little concerned about the paint, especially if low quality, eventually flaking and turning to dust, even though not in direct sunlight, possibly causing more problems.
Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.I haven't played with black yet but i used Rust. flat white paint made for plastic and uv resistant. I am not sure how you tell if black will be absorbent or not, just thought black would absorb being black and all lol. Need a paint guru to chime in here. :???:Not a paint guru, so I'll just state what's probably more or less obvious. If you paint the inside of your shield you better give the paint plenty of time to dry before putting the sensor in, as there seems to already be a lot of concern about contamination. Also I would be a little concerned about the paint, especially if low quality, eventually flaking and turning to dust, even though not in direct sunlight, possibly causing more problems.
Yes, they do. I've worked on the AWOS III-PT. Unless they have done something custom it doesn't use separate sensors for temperature and humidity. It uses a combination 5190-F temperature/humidity sensor inside the 8190 MARS.
Interesting!
My local airport, KSAW, seems to run about 2-3 degrees low lately in dewpoint as compared to other airports/RAWS stations. Just checked the spec and max error is 3F between +30 and +90F. So, I guess they're within spec!
Do the AWOS IIIP/T capacitive sensors tend to drift noticeably and, if so, which direction is typical?
Also, any idea of the aspiration rate (m/s, cfm, whatever)?
Nice info in this thread. Thanks guys.
KCID...do you have any spec documentation for the DTS1? I can't find much through Google.
| At +15 ... +25 °C (+59 ... +77 °F) | ±1 %RH (0 ... 90 %RH) |
| ±1.7 %RH (90 ... 100 %RH) | |
| At −20 ... +40 °C (−4 ... +104 °F) | ±(1.0 + 0.008 × reading) %RH |
| At −40 ... −20 °C (−40 ... −4 °F) | ±(1.2 + 0.012 × reading) %RH |
| At +40 ... +60 °C (+104 ... +140 °F) | ±(1.2 + 0.012 × reading) %RH |
| At −60 ... −40 °C (−76 ... −40 °F) | ±(1.4 + 0.032 × reading) %RH |
Absolutely...'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.I haven't played with black yet but i used Rust. flat white paint made for plastic and uv resistant. I am not sure how you tell if black will be absorbent or not, just thought black would absorb being black and all lol. Need a paint guru to chime in here. :???:Not a paint guru, so I'll just state what's probably more or less obvious. If you paint the inside of your shield you better give the paint plenty of time to dry before putting the sensor in, as there seems to already be a lot of concern about contamination. Also I would be a little concerned about the paint, especially if low quality, eventually flaking and turning to dust, even though not in direct sunlight, possibly causing more problems.
I'm sure there are exceptions, but ASOS's are placed at larger airports that handle more passenger traffic than say, at a strictly GA airport and are serviced by NWS or FAA techs. AWOS's are usually at the, as we say, "dink" airports and are "serviced" by airport management.The typical problem I see with AWOS systems is the lack of a consistent maintenance schedule.Yes, they do. I've worked on the AWOS III-PT. Unless they have done something custom it doesn't use separate sensors for temperature and humidity. It uses a combination 5190-F temperature/humidity sensor inside the 8190 MARS.
Interesting!
My local airport, KSAW, seems to run about 2-3 degrees low lately in dewpoint as compared to other airports/RAWS stations. Just checked the spec and max error is 3F between +30 and +90F. So, I guess they're within spec!
Do the AWOS IIIP/T capacitive sensors tend to drift noticeably and, if so, which direction is typical?
Also, any idea of the aspiration rate (m/s, cfm, whatever)?
I'm sure there are exceptions, but ASOS's are placed at larger airports that handle more passenger traffic than say, at a strictly GA airport and are serviced by NWS or FAA techs. AWOS's are usually at the, as we say, "dink" airports and are "serviced" by airport management.The typical problem I see with AWOS systems is the lack of a consistent maintenance schedule.Yes, they do. I've worked on the AWOS III-PT. Unless they have done something custom it doesn't use separate sensors for temperature and humidity. It uses a combination 5190-F temperature/humidity sensor inside the 8190 MARS.
Interesting!
My local airport, KSAW, seems to run about 2-3 degrees low lately in dewpoint as compared to other airports/RAWS stations. Just checked the spec and max error is 3F between +30 and +90F. So, I guess they're within spec!
Do the AWOS IIIP/T capacitive sensors tend to drift noticeably and, if so, which direction is typical?
Also, any idea of the aspiration rate (m/s, cfm, whatever)?
Like I said, I'm sure one size doesn't fit all.
I think the only way to properly test is having matching thermometers. These SHT31's are all the same within .1°F but
if anyone wants to follow this Davis station with 7714 pictured above and airport ASOS I'll add links with 5 minute updates.
links with 5 minute updates about 2 miles distance.
https://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=E7498
https://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KVTN&unit=0&timetype=LOCAL/
[ You are not allowed to view attachments ]
I think the only way to properly test is having matching thermometers. These SHT31's are all the same within .1°F but
if anyone wants to follow this Davis station with 7714 pictured above and airport ASOS I'll add links with 5 minute updates.
links with 5 minute updates about 2 miles distance.
https://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=E7498
https://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KVTN&unit=0&timetype=LOCAL/
[ You are not allowed to view attachments ]
See where your 31 went up to 100% today.
So far, the DP is matching up with the Airport
Flat Black and Gloss White...but I'm interested to hear what others use.I was wondering about some kind of tape for the black that could be used to line the chamber? Seems like it would be safer than paint, and easier to remove if needed, depending on the adhesive used. My first thought was electrical tape, but it would probably be too shiny. Maybe some kind of gaffer's tape or something?
As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
I'm starting this test over today because the first day shield being used was modified with bottom removed so I could insert another sensor inside.
As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
I'm starting this test over today because the first day shield being used was modified with bottom removed so I could insert another sensor inside.
I believe this was allowing reflective heat waves inside sensor chamber causing a slight warming. I went back to stock shield with AC fan today. I'm currently seeing FARS running .3 to .5 F cooler with completely stock shield. Still not bad for passive but will need to continue testing.
[ You are not allowed to view attachments ]
Titanium dioxide based white paint, its what they use on the National Solar Observatory Telescope which was on Kitt Peak.
If it is good enough for the research guys, it should be good enough for us.
PS, no idea where they get the stuff. Maybe an auto paint store which seems to be able to get just about anything might do?
Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
The following reconditioningJust keep the word "may" in mind. It may bring it back, but then it may not. Worth a try if the sensor is already contaminated.
procedure may bring the sensor back to calibration state:
Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I wonder how low Rh my oven gets? Likely not <5%. Not in a Gulf Coast region household oven anyway.
.
Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I wonder how low Rh my oven gets? Likely not <5%. Not in a Gulf Coast region household oven anyway.
.
I used crock pot SLOweather's idea. I just made a tin foil tent/platform keeping sensor off bottom and baked 10 hours keeping lid cracked open 1/2 to 3/4". Using temperature gun I was between 110-125c. Spark Fun does all sensor baking at 125° even though they say 105°c in reconditioning literature.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
Sounds like a mixed bag, at best. But it's good to have someone else attempt it. More data, either way.
Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I wonder how low Rh my oven gets? Likely not <5%. Not in a Gulf Coast region household oven anyway.
.
I used crock pot SLOweather's idea. I just made a tin foil tent/platform keeping sensor off bottom and baked 10 hours keeping lid cracked open 1/2 to 3/4". Using temperature gun I was between 110-125c. Spark Fun does all sensor baking at 125° even though they say 105°c in reconditioning literature.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
I assume this is the whole assembly? i.e. the PCB and 6c cable attached? If so, what did you do with the cable during baking to keep it of the bottom?
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
Sounds like a mixed bag, at best. But it's good to have someone else attempt it. More data, either way.
Yeah, I thought about that right after I posted, #-o let the cord hang out. I cut a 1 inch length off a paper towel core and ran the cable through it and set the lid on it. It's baking now, but taking a while to get to temp. I remembered too that I have an industrial oven temp meter w/probe that I used for baking Cerakote. Its perfect for this.Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I wonder how low Rh my oven gets? Likely not <5%. Not in a Gulf Coast region household oven anyway.
.
I used crock pot SLOweather's idea. I just made a tin foil tent/platform keeping sensor off bottom and baked 10 hours keeping lid cracked open 1/2 to 3/4". Using temperature gun I was between 110-125c. Spark Fun does all sensor baking at 125° even though they say 105°c in reconditioning literature.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
I assume this is the whole assembly? i.e. the PCB and 6c cable attached? If so, what did you do with the cable during baking to keep it of the bottom?
Cable is attached but leave hanging out. I remove sensor if attached to board that slides into 24 hr. fars sensor chamber and remove filter cap.
Yeah, I thought about that right after I posted, #-o let the cord hang out. I cut a 1 inch length off a paper towel core and ran the cable through it and set the lid on it. It's baking now, but taking a while to get to temp. I remembered too that I have an industrial oven temp meter w/probe that I used for baking Cerakote. Its perfect for this.Probably not. As I recall, you can bake the sensor to recondition it. See the Sensirion handling docs and spec sheets.Thanks, Found it: (This is for the SHT-15)As in Permanently ruin it ? :shock:Absolutely, 'out-gassing' of paint volatile's will detrimentally affect RH sensor accuracy.
1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h
I wonder how low Rh my oven gets? Likely not <5%. Not in a Gulf Coast region household oven anyway.
.
I used crock pot SLOweather's idea. I just made a tin foil tent/platform keeping sensor off bottom and baked 10 hours keeping lid cracked open 1/2 to 3/4". Using temperature gun I was between 110-125c. Spark Fun does all sensor baking at 125° even though they say 105°c in reconditioning literature.
Some of my sensors only maxed at 96% new baking didn't correct. If sensor reached 98+ new and stopped baking may restore to original performance.
I assume this is the whole assembly? i.e. the PCB and 6c cable attached? If so, what did you do with the cable during baking to keep it of the bottom?
Cable is attached but leave hanging out. I remove sensor if attached to board that slides into 24 hr. fars sensor chamber and remove filter cap.
Also through some desiccant packs in with it... maybe it will help soak up some humidity.
Thanks for all the Info!
I used crock pot SLOweather's idea.
Well i pulled the trigger on what is supposed to be a really great passive shield from Barani. I am getting the pro and standard shields to compare the two against each other and of course the Davis fars. It sure would be nice to have a passive shield and eliminate the fan and batteries that go with the fars shield. One of the things i will be checking is how the sensor fits into the shields the pro only has an opening of 1.6 inches and the standard has an opening of 2.6 which should allow the sensor to fit. Here is the url to the two shields https://www.allmeteo.com/solar-radiation-shield/
Well it looks like it will by diameter measurement just not sure if the big filter will make it tight. I have looked at a bunch of the sensor boards and it looks like the board could be made smaller by removing the extra to the left of where the shield snaps in, there does not appear to be any circuit printed there and it would come close to fitting in the pro shield with a factory filter which is so much smaller. It sure would be nice to get rid of all the fars stuff and it will be interesting to see how it handles the high humidity problem also.
Well i pulled the trigger on what is supposed to be a really great passive shield from Barani. I am getting the pro and standard shields to compare the two against each other and of course the Davis fars.They were on here when this came out and it looks promising. Thing I don't like is there claim to be as good or better than aspirated shields. Well, what aspirated shields? Just because a PWS has a fan doesn't make a bad shield good, that's for sure. They do do a comparison against an aspirated VP2, but the graph colors are so close together it makes it damn near impossible to distinguish between the two, but I get the point, they're close. That being said, they leave out one tiny little factor, wind speed during the test. :roll: Kinda makes a difference.
Now all i have to do is sit here a wait for them to show up, that is the hard part lol.Yeah, it's been Christmas for a lot of you guys around here, buying stuff left and right, kinda jealous.... Actually, I'm seriously considering picking up a psycho-dyne, as CW7491 has, and see if the drier air here has lessened the wet bias and/or premature aging, as I'm leaning to believe it has.
Now all i have to do is sit here a wait for them to show up, that is the hard part lol.Yeah, it's been Christmas for a lot of you guys around here, buying stuff left and right, kinda jealous.... Actually, I'm seriously considering picking up a psycho-dyne, as CW7491 has, and see if the drier air here has lessened the wet bias and/or premature aging, as I'm leaning to believe it has.
I replaced my top two plates and solar PCB cover about this time last year due to this exact issue, except I managed 10 years outta mine. The bottom plates are still like new. Only structural replacement parts I've ever needed for my VP2.Now all i have to do is sit here a wait for them to show up, that is the hard part lol.Yeah, it's been Christmas for a lot of you guys around here, buying stuff left and right, kinda jealous.... Actually, I'm seriously considering picking up a psycho-dyne, as CW7491 has, and see if the drier air here has lessened the wet bias and/or premature aging, as I'm leaning to believe it has.
BE VERY CAREFUL disassembling your FARS plates! With only 6.3 years use, mine crumbled in my hand as I replaced fan...replacement plates ordered from SI.
Yep, those are the plates that fell apart as I handled them. So much for being UV-resistant -- NOT!I replaced my top two plates and solar PCB cover about this time last year due to this exact issue, except I managed 10 years outta mine. The bottom plates are still like new. Only structural replacement parts I've ever needed for my VP2.Now all i have to do is sit here a wait for them to show up, that is the hard part lol.Yeah, it's been Christmas for a lot of you guys around here, buying stuff left and right, kinda jealous.... Actually, I'm seriously considering picking up a psycho-dyne, as CW7491 has, and see if the drier air here has lessened the wet bias and/or premature aging, as I'm leaning to believe it has.
BE VERY CAREFUL disassembling your FARS plates! With only 6.3 years use, mine crumbled in my hand as I replaced fan...replacement plates ordered from SI.
Have a new shield to test in few weeks. The Metoshield standard will fit the Davis sensor now, no mention if this was with or without filter cover.
If interested in going FARSLESS (I am), I'll be testing these units when I finally get one or two in hand.
It will be a couple weeks before in stock however in meantime I'll continue testing the Davis 7714.
Just got an email from Jan Barani that my pro shield will ship out right away as they are in stock in the usa store and the standard will be a little later as they are about to be shipped to the usa store and have to go thru all the processing for imported products.
Just got an email from Jan Barani that my pro shield will ship out right away as they are in stock in the usa store and the standard will be a little later as they are about to be shipped to the usa store and have to go thru all the processing for imported products.
Your sensor won't fit in the Pro will it?
Big announcement I posted in original thread also.
The Meteoshield Standard Shield will now accept the Davis SHT sensor. Not sure if this is with large Davis filter however.
They are now taking orders and gave a discount code for fellow forum members if interested.
They expect deliveries to start in about a week.
Code: $25DISCOUNT will work through August 31
Purchase in USA at: https://www.allmeteo.com/meteo-shop/solar-radiation-shield-for-weather-station-lite
They have already done some tests. Including the VP2 FARS.
https://www.allmeteo.com/radiation-shield-comparisons/ (https://www.allmeteo.com/radiation-shield-comparisons/)
They have already done some tests. Including the VP2 FARS.
https://www.allmeteo.com/radiation-shield-comparisons/ (https://www.allmeteo.com/radiation-shield-comparisons/)
In weather, as in commerce, CAVEAT EMPTORThey have already done some tests. Including the VP2 FARS.
https://www.allmeteo.com/radiation-shield-comparisons/ (https://www.allmeteo.com/radiation-shield-comparisons/)
Well it's their product, I know how those test can go. :-P
I'll feel better seeing with my own eyes. That test was done without using the SHT also they used one of the skinny sensors so whole new ballgame with sht taking up more room maybe reducing airflow.
I regret putting the discount code out if shield is a failure and people waste money.
In weather as in commerce: CAVEAT EMPTORThey have already done some tests. Including the VP2 FARS.
https://www.allmeteo.com/radiation-shield-comparisons/ (https://www.allmeteo.com/radiation-shield-comparisons/)
Well it's their product, I know how those test can go. :-P
I'll feel better seeing with my own eyes. That test was done without using the SHT also they used one of the skinny sensors so whole new ballgame with sht taking up more room maybe reducing airflow.
I regret putting the discount code out if shield is a failure and people waste money.
They have already done some tests. Including the VP2 FARS.And like I stated on the previous page, they conveniently left out the wind, or lack thereof. Without wind data, this test is basically meaningless. Any decent passive shield will keep up with a FARS, when there's enough wind. This thing could be the greatest passive shield since sliced bread, but leaving out the most crucial element, the wind, makes me dubious.
https://www.allmeteo.com/radiation-shield-comparisons/ (https://www.allmeteo.com/radiation-shield-comparisons/)
Todays test #1 is the passive shield 7714. Looks like +1°F difference on high temperature under mainly light wind speeds. Haven't looked it over exactly where solar, wind, temperature were. Just putting it out for any others who want to evaluate and comment.
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]
Todays test #1 is the passive shield 7714. Looks like +1°F difference on high temperature under mainly light wind speeds. Haven't looked it over exactly where solar, wind, temperature were. Just putting it out for any others who want to evaluate and comment.
Looks to me as though DFARS would likely be adequate, of course, you're not at 100ºF and still winds.
Here is some interesting research on radiation shields...
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0426(2001)018%3C0851%3ATEOTAM%3E2.0.CO%3B2
So I'm confused. The 7714 passive shield plates come out of the box, black on the underside ? Or you had to paint them?
So I'm confused. The 7714 passive shield plates come out of the box, black on the underside ? Or you had to paint them?
I painted mine Flat Black just bottom plate where sensor mounts and the nearest top plate toward sensor. I used painters blue tape edges around upper plate so only white (no black) was exposed to sun. Instructions on assembly can be tricky. Better to assembly first time then once you figure that out you will understand what parts I painted black.
So I'm confused. The 7714 passive shield plates come out of the box, black on the underside ? Or you had to paint them?
I painted mine Flat Black just bottom plate where sensor mounts and the nearest top plate toward sensor. I used painters blue tape edges around upper plate so only white (no black) was exposed to sun. Instructions on assembly can be tricky. Better to assembly first time then once you figure that out you will understand what parts I painted black.
Oh OK..So it was the Metoeshield that comes black on the underside. I got them confused.
I just looked at the Meteoshield specs and It's a lot smaller than the Davis shields as far as diameter. Inside diameter is ~ 2.56". But if you could mount the SHTxx PCB vertically (as in the cable hanging straight down) you should have ~.5" on either side which would allow you to place the PCB off-center. thereby positioning the sensor about center. This would allow an upward draft through the center with only the Davis filter cap (assuming you use it) in the airflow. However, horizontal airflow would be blocked. But according to the design intent, and unlike most gill plate shields.. natural aspiration should be a "quasi-spiral-vertical" (Helical) movement, should it not?
So I'm confused. The 7714 passive shield plates come out of the box, black on the underside ? Or you had to paint them?
I painted mine Flat Black just bottom plate where sensor mounts and the nearest top plate toward sensor. I used painters blue tape edges around upper plate so only white (no black) was exposed to sun. Instructions on assembly can be tricky. Better to assembly first time then once you figure that out you will understand what parts I painted black.
Oh OK..So it was the Metoeshield that comes black on the underside. I got them confused.
I just looked at the Meteoshield specs and It's a lot smaller than the Davis shields as far as diameter. Inside diameter is ~ 2.56". But if you could mount the SHTxx PCB vertically (as in the cable hanging straight down) you should have ~.5" on either side which would allow you to place the PCB off-center. thereby positioning the sensor about center. This would allow an upward draft through the center with only the Davis filter cap (assuming you use it) in the airflow. However, horizontal airflow would be blocked. But according to the design intent, and unlike most gill plate shields.. natural aspiration should be a "quasi-spiral-vertical" (Helical) movement, should it not?
I was in contact with Jan at Metoshield about the big stock filter, he thought it would work. Until I get the shield and see not totally convinced so ordered some of the small filters just in case.
I was wondering the same thing about the big sensor blocking the spiraling air
flow or disrupting it so much it might not meet the specs of a smaller round probe designed for it. I would think at the least it might be the thing to do to remove the big davis filter in favor of the smaller low profile of the sf1.
I think you’re fine. I believe the SF1 was for the SHT1x.I was wondering the same thing about the big sensor blocking the spiraling air
flow or disrupting it so much it might not meet the specs of a smaller round probe designed for it. I would think at the least it might be the thing to do to remove the big davis filter in favor of the smaller low profile of the sf1.
I thought the 31's took the SF2's You sent me a link. That's what I ordered. So do I have the wrong filter coming?
Sensirion says its the SF2. #-o SF2 Filter Cap
For SHT2x and SHT3x Humidity Sensors
https://www.sensirion.com/en/environmental-sensors/humidity-sensors/filter-cap-sf2/
Here is some interesting research on radiation shields...
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0426(2001)018%3C0851%3ATEOTAM%3E2.0.CO%3B2
Summary:
ASOS > CRS > MMTS > Gill = rank of solar radiation shield effectiveness.
CRS > MMTS > Gill > ASOS = DAYTIME rank of infrared radiation shielding effectiveness.
Gill ≥ MMTS > CRS ≈ ASOS = NITETIME rank of infrared radiation shielding effectiveness.
...where:
ASOS = Automated Surface Observing System shield
MMTS = Maximum-Minimum Temperature System shield
CRS = Cotton Region (Stevenson) Shelter.
Gill = multliple-plate cylindrical shaped shield
I think you’re fine. I believe the SF1 was for the SHT1x.I was wondering the same thing about the big sensor blocking the spiraling air
flow or disrupting it so much it might not meet the specs of a smaller round probe designed for it. I would think at the least it might be the thing to do to remove the big davis filter in favor of the smaller low profile of the sf1.
I thought the 31's took the SF2's You sent me a link. That's what I ordered. So do I have the wrong filter coming?
Sensirion says its the SF2. #-o SF2 Filter Cap
For SHT2x and SHT3x Humidity Sensors
https://www.sensirion.com/en/environmental-sensors/humidity-sensors/filter-cap-sf2/
Here is some interesting research on radiation shields...
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0426(2001)018%3C0851%3ATEOTAM%3E2.0.CO%3B2
Summary:
ASOS > CRS > MMTS > Gill = rank of solar radiation shield effectiveness.
CRS > MMTS > Gill > ASOS = DAYTIME rank of infrared radiation shielding effectiveness.
Gill ≥ MMTS > CRS ≈ ASOS = NITETIME rank of infrared radiation shielding effectiveness.
...where:
ASOS = Automated Surface Observing System shield
MMTS = Maximum-Minimum Temperature System shield
CRS = Cotton Region (Stevenson) Shelter.
Gill = multliple-plate cylindrical shaped shield
That's the old ASOS shield (circa 2000) that had the chilled mirror in it. They had to leave the bottom open which really messed it up with ground reflected radiation, especially at night. They discuss this in the abstract and then again around pp 861-863 in the paper.
The newer ASOS's have a separate housing for dew point. Not sure, but I doubt, the aspirated temperature shield is still left open at the bottom now. Ron would have to verify.
I think you’re fine. I believe the SF1 was for the SHT1x.I was wondering the same thing about the big sensor blocking the spiraling air
flow or disrupting it so much it might not meet the specs of a smaller round probe designed for it. I would think at the least it might be the thing to do to remove the big davis filter in favor of the smaller low profile of the sf1.
I thought the 31's took the SF2's You sent me a link. That's what I ordered. So do I have the wrong filter coming?
Sensirion says its the SF2. #-o SF2 Filter Cap
For SHT2x and SHT3x Humidity Sensors
https://www.sensirion.com/en/environmental-sensors/humidity-sensors/filter-cap-sf2/
Could be the SF1 has to be larger, maybe that's what he likes it for better handling and gluing down. Can't image any sensor smaller than the tiny 31's so about any filter should fit.
Just had a thought if i remember right i think that a passive shield is supposed to run cooler at night than a fars. It will be another thing i check out tonight to see how much if any temp difference there is.
Barani shields are still in customs, takes about a week maybe getting close now. Once retailer receives they get shipped to customers.
Barani shields are still in customs, takes about a week maybe getting close now. Once retailer receives they get shipped to customers.
OK... Barani...Meteoshield...Standard shield ](*,) Are we all talking about the same thing here?
And If so, Doesn't Jerryg and Jgentry already have the Meteoshields? How are they held up in Customs...???
Barani shields are still in customs, takes about a week maybe getting close now. Once retailer receives they get shipped to customers.
OK... Barani...Meteoshield...Standard shield ](*,) Are we all talking about the same thing here?
And If so, Doesn't Jerryg and Jgentry already have the Meteoshields? How are they held up in Customs...???
Actual name of shield is METEOSHIELD made by BARANI DESIGN brand of meteorological sensors. Two versions STANDARD version was designed to hold the Davis size sensor. PRO sensor chamber isn't as wide with black interior and longer for some of the high dollar sensors to fit.
allMETEO is the distributor.
All I know is Jerry got his yesterday and when I first posted was told by distributor allMETEO in email they would be in customs for about a week and as soon as they cleared and they received would ship orders out.
I think Jerry got a set of shields which had already cleared customs prior because first big order went to USGA which cleaned original stock out so this is another batch being received by distributor.
Barani shields are still in customs, takes about a week maybe getting close now. Once retailer receives they get shipped to customers.
OK... Barani...Meteoshield...Standard shield ](*,) Are we all talking about the same thing here?
And If so, Doesn't Jerryg and Jgentry already have the Meteoshields? How are they held up in Customs...???
Actual name of shield is METEOSHIELD made by BARANI DESIGN brand of meteorological sensors. Two versions STANDARD version was designed to hold the Davis size sensor. PRO sensor chamber isn't as wide with black interior and longer for some of the high dollar sensors to fit.
allMETEO is the distributor.
All I know is Jerry got his yesterday and when I first posted was told by distributor allMETEO in email they would be in customs for about a week and as soon as cleared and received would ship orders out.
I think Jerry got a set of shields which had already cleared customs prior because first big order went to USGA which cleaned original stock out so this is another batch being received by distributor.
Jerry, do you have an RM Young or Vaisala radiation shield to put head to head against the Baranti?
They have been around a long time, are 'standard' but very pricey new (eBay has them pretty good once in awhile) and I'm wondering if the new design as taken the passive method one step further towards true ambient temps.
I recall seeing a graph from Young, I think, on how wind speed affects the temperature, based against temperature. It was as much as 4 degrees different on a calm warm day, if I recall.
Are you also logging if there is sunshine vs. overcast to see if there are greater degrees of disparity on a cloudy day vs. sunshine?
Well as far as pictures go don't know how to post on here, might figure it out. Its not too fancy just mounted on my tower with an 8 feet galvanized pipe mounted cross ways on it with virtical mounting pipes. The standard shield is on one end and the pro is on the other connected to the iss mounted on the standard Davis mount with the uv and solar sensors so have a longer cable made up on my 75 sensor i made so i could mount the shield facing north so as not to shade the sensors. The standard was easier even though it had the shorter cable from the 31 sensor. I used the metal Davis mounting plate that fits the fars setup and i mounted the iss using one of the holes nearest the shield, i do not use Davis rain gauges all mine are external gauges so i don't have the problem of keeping it level and bulky. This mount is my test mount and i don't use it for anything else so didn't need rain gauge or anything else to mount on the plate. If i had the rain gauge set up then i would have had to extend the cable or figure out some really fancy way moving the iss to get it better located but then rain gauge wouldn't reach ](*,)
Pictures standard and pro
Short update averages from 10 am to 2:30 pm pro 83.9 standard 84.4 fars 84.5
sht 75
Yes the pro shield is on my main uploading site and if it keeps working the way it has been it will stay that way from now on. \:D/
Forgot to answer other question, it is more of an educated guess but with the good air flow on the barani shield i really never noticed any real lag time between the two.
No i don't think it's necessary or they would have made the adapter set up air tight because the shield at the top of the adapter is wide open so same-o same-o. Here are my final averages for the day. pro 86.7 standard 87.3 and fars 87.3 how about that match, uncanny how it worked out.
Just saw this from Barani's web site:
Removes influences of city walls on temperature
Not affected by radiating heat from city walls, pavement, and sun reflections, real-air-temperature measurements are a reality with the MeteoShield. Urban climate research with WMO accuracy in a dense urban environment is now possible.
Learn to trust your data.
Really?? Someone please explain to me how this shield is so smart it knows where the heat's coming from and how to ignore it?
Like I said before, this shield could be the best thing since sliced bread, but some of their statements are preposterous.
Just saw this from Barani's web site:
Removes influences of city walls on temperature
Not affected by radiating heat from city walls, pavement, and sun reflections, real-air-temperature measurements are a reality with the MeteoShield. Urban climate research with WMO accuracy in a dense urban environment is now possible.
Learn to trust your data.
Really?? Someone please explain to me how this shield is so smart it knows where the heat's coming from and how to ignore it?
Like I said before, this shield could be the best thing since sliced bread, but some of their statements are preposterous.
Yes, I wondered the same thing. Maybe they mean only the reflected radiation itself (still questionable), but the claim ignores that walls/pavement also conduct heat into the air once they absorb sunshine. That warmed air is certainly not going to be rejected by the shield. That's part of the urban heat island effect. In our small, northerly town that phenomenon is good for at least 1-2F of warming on a sunny, summer day compared to outlying communities at the same elevation.
Going to do max/min temp on the stations. Pro 91.3/73.8 standard 91.3/73.9 fars 91.7/73.7Not saying it's right or wrong, but certainly one reason the FARS is reading higher is for the simply fact it's drawing air across the sensor allowing for more "direct/instant" reading of the temp whereas the passive is missing it.
Going to do max/min temp on the stations. Pro 91.3/73.8 standard 91.3/73.9 fars 91.7/73.7
Yeah i thought about the upload time i might lower it to 5 minutes for test but i am looking at real time here so did not cross my mine. I know, a real bummer, i had 5 days of clear blue skies with light to calm morning winds and seabreeze winds in the afternoon, perfect for testing and no shields :-( I got just one day and that was afternoon time just before seabreeze hit. I thought i might get a shot this am but clouds and rain already moving in and morning sun is being block by heavy clouds in the east. I would like to get just one good full day of light wind and sun to test things but the weather gods are laughing at me lol.
The pro looks like it is put together like the davis plates, stacked with long screws holding them together. The pro is like the standard but with a smaller black louvered shield inside it.
I think it's important inside of these shields be non reflective flat black. Why they didn't' do it on standard shield? Maybe selling point for the more expensive pro model.
Vaisala does their new shields this way, it's almost become a standard now for absorbing accumulated heat thus eliminating the possible warming inside the shield.
I was testing black spray paints yesterday and figured out you can accelerate the drying time substantially reducing odor by using a hair dryer. I'm going to look at hardware stores today for some Krylon Fusion black silk. This paint claims to work well on plastic and 10 minute dry times. I currently have the Valspar includes primer for plastics which is good quality paint but odor sticks around a day or so.
https://my.vaisala.net/Vaisala%20Documents/Vaisala%20News%20Articles/VN160/VN160_New_Radiation_Shield_Models_DTR502B_and_DTR503A.pdf
Comparing shields is really a tough thing to do, i was thinking about the davis fars and in their comparison test they state the error was no more than say .6f higher than the rm young but you have to input the rm young also has an error of say .5f so your davis fars error could be over 1 degree and still be in spec. This is why my wondering about the pro readings with some wind blowing always being lower than the fars could mean the pro is closer to the actual temp and the fars is showing that potential 1f degree error. The test you show could be against a really good fars with great specs and that .9 with no wind would be great specs, after all we are talking about a cost effective shield that gives good results unless there is no wind and even then usable temps. We need to keep in mind these test are under the most severe conditions as far as no wind and high isolation conditions which only occur at certain times. Where i live the wind generally blows during the day and only lays at night but with no sun at night no heating effect. So it is really dependent on your location and wind conditions that will determine how well any given shield works. What is good for me may not work for you. Even the best fars have a temp rise error at max isolation and low wind. I was looking at the one they use for the climate network that cost 750 smackers and it has a low but it is there temp error. When it comes to daytime temp readings i use the nighttime temp comparison between the three shields and they never vary more than a tenth at night so any difference during the day is due to the shield itself and how it handles the varying conditions.You use the stock fan in your FARS, correct? Have you tried comparing 2 Davis FARS -- one with a stock fan and one with more CFMs?
Yes i did for some time and after having sensor failures because of moisture problems i went back to the davis set up because of the lower fan speed at night. This is the second morning that i have cut the fan off at night and got the same results much better readings in the mornin g that follows the other shields pretty well and not lagging behind for an up to an hour. I really think a fars if pretty tough on sensors in high humidity areas and i plan on running the pro shield for good. At 9 am the standard was 84.6 and the pro was 84.4 with winds 4-6 mph and still sunny.It's interesting that you fine the RH lags in the morning with a FARS. Even with dewpoints near 70F, I've always found the opposite.
To start still dark and no wind pro and standard showing 73.7 now at 8 am wind 2 mph and sunny skies pro is 79.1 and standard is 79.3 . More later.Just saw CRP is 83/81 right now. I don't know how you guys handle that down there.
To start still dark and no wind pro and standard showing 73.7 now at 8 am wind 2 mph and sunny skies pro is 79.1 and standard is 79.3 . More later.Just saw CRP is 83/81 right now. I don't know how you guys handle that down there.
I think it's important inside of these shields be non reflective flat black. Why they didn't' do it on standard shield? Maybe selling point for the more expensive pro model.
Vaisala does their new shields this way, it's almost become a standard now for absorbing accumulated heat thus eliminating the possible warming inside the shield.
I was testing black spray paints yesterday and figured out you can accelerate the drying time substantially reducing odor by using a hair dryer. I'm going to look at hardware stores today for some Krylon Fusion black silk. This paint claims to work well on plastic and 10 minute dry times. I currently have the Valspar includes primer for plastics which is good quality paint but odor sticks around a day or so.
https://my.vaisala.net/Vaisala%20Documents/Vaisala%20News%20Articles/VN160/VN160_New_Radiation_Shield_Models_DTR502B_and_DTR503A.pdf
Problem with spray paints is they are all high in VOCs which is not good for the sensor. You can find reduced VOC spray paint, but it's still not "low" in VOCs and I'd question the quality (flaking).
This is why my wondering about the pro readings with some wind blowing always being lower than the fars could mean the pro is closer to the actual temp and the fars is showing that potential 1f degree error.
I have had my modified 75 in a Meteoshield Pro for several days now with the stock Davis filter. Here is my station dw5686 if you want to follow along with my stats compared to MADIS and two ASOS stations one 5 miles east (CLT) and the other 8miles southwest (AKH). I also upload to WxUnderground if you want to follow my data more in real time.
https://weather.gladstonefamily.net/site/D5686
https://www.wunderground.com/personal-weather-station/dashboard?ID=KNCBELMO18#history
So far I'm very happy as it seems my CWOP stats haven't changed very much at all. Perhaps running just .2F to .3F warmer compared to other stations than I used to. When comparing highs and lows I to local ASOS I go back and look at my one minute data and find the 5min running avg for the high and low for the day. I think this is important that you do this since when comparing your readings with ASOS as it smooths out temperature data this way. Anyhow, I have been running either even or one degree cooler than my local ASOS stations which is on par when I was running a davis FARS with stock fan, actually the replacement 3V motor from Nichibo.
Weather has been great for testing except for cloud cover. Hot humid afternoons with light winds, but with scattered to broken layers. Want to eventually get around to some side by side testing with my FARS but from what jerryg has found in his testing it sounds like both the meteoshields and especially the pro may be promising alternatives to aspirated shields.
I have had my modified 75 in a Meteoshield Pro for several days now with the stock Davis filter. Here is my station dw5686 if you want to follow along with my stats compared to MADIS and two ASOS stations one 5 miles east (CLT) and the other 8miles southwest (AKH). I also upload to WxUnderground if you want to follow my data more in real time.
https://weather.gladstonefamily.net/site/D5686
https://www.wunderground.com/personal-weather-station/dashboard?ID=KNCBELMO18#history
So far I'm very happy as it seems my CWOP stats haven't changed very much at all. Perhaps running just .2F to .3F warmer compared to other stations than I used to. When comparing highs and lows I to local ASOS I go back and look at my one minute data and find the 5min running avg for the high and low for the day. I think this is important that you do this since when comparing your readings with ASOS as it smooths out temperature data this way. Anyhow, I have been running either even or one degree cooler than my local ASOS stations which is on par when I was running a davis FARS with stock fan, actually the replacement 3V motor from Nichibo.
Weather has been great for testing except for cloud cover. Hot humid afternoons with light winds, but with scattered to broken layers. Want to eventually get around to some side by side testing with my FARS but from what jerryg has found in his testing it sounds like both the meteoshields and especially the pro may be promising alternatives to aspirated shields.
Very nice so another with a pro.
Has me thinking do I want to change at least 1 shield coming to a pro?
Just a quickie, i got a 31 to fit inside the pro, tight, but it will go when you whack off the excess board on the right side of the sensor.Very nice now what do I do? LOL
It's clear the 7714 is a great little shield. Doesn't take much wind and performs just as well.No doubt that it's really good, but the thing is, if passive shields were that good, fans would have never been used in the first place.
That's true but it depends on how good your fars is doing, some are better than others. Just having a fan doesn't mean you have the best.Of course! All I'm saying is that fans aren't going anywhere in high end measurements.
It's clear the 7714 is a great little shield. Doesn't take much wind and performs just as well.No doubt that it's really good, but the thing is, if passive shields were that good, fans would have never been used in the first place.
It'll be a cold day in H E double hockey sticks before you see an ASOS with a passive shield.
Something just came up from hwcorder post about using stock filter on modified 73. How about others? I don't see a specifically made filter for these so do they even require a filter? if so is it just some homebrew like wrapping sensor in davis type filter material?The Campbell Sci tem/hum probe uses the 75.
Measurement Below 0 °C
The CS215 provides a humidity reading that is referenced to the saturated water vapor pressure above liquid water, even at temperatures below 0 °C, where ice might form. This is the common way to express relative humidity and is as defined by the World Meteorological Organization. If an RH value is required to be referenced to ice, the CS215 readings will need to be corrected.
One consequence of using water as the reference is that the maximum humidity that will normally be output by the sensor for temperatures below freezing is as follows:
100% RH at 0 °C
95% RH at –5 °C
91% RH at –10 °C
87% RH at –15 °C
82% RH at –20 °C
78% RH at –25 °C
75% RH at –30 °C
In practical terms this means that, for instance, at –20 °C the air is effectively fully saturated when the sensor outputs 82% RH.
Something just came up from hwcorder post about using stock filter on modified 73. How about others? I don't see a specifically made filter for these so do they even require a filter? if so is it just some homebrew like wrapping sensor in davis type filter material?The Campbell Sci tem/hum probe uses the 75.
https://www.campbellsci.com/cs215-l (click "read more")
I'd assume that probe filter housing is available somewhere in accessories or replacement parts.
Looks pretty good so i order some, hope they are as shown lol.Same here, used paypal. I heard they are trustworthy, some people buy cameras all the time.
Something just came up from hwcorder post about using stock filter on modified 73. How about others? I don't see a specifically made filter for these so do they even require a filter? if so is it just some homebrew like wrapping sensor in davis type filter material?The Campbell Sci tem/hum probe uses the 75.
https://www.campbellsci.com/cs215-l (click "read more")
I'd assume that probe filter housing is available somewhere in accessories or replacement parts.
The filter cap they use is https://www.campbellsci.com/p18142 and you request a quote. surely this isn't what most use is it? When they say request a quote it's beyond my price... :grin:
It would be nice to know how it shapes out with the 75 being phased out.Really need Sensirion to spit out a pin SHT35-LSS. Maybe a few of us could email them some encouragement. ;)
Something just came up from hwcorder post about using stock filter on modified 73. How about others? I don't see a specifically made filter for these so do they even require a filter? if so is it just some homebrew like wrapping sensor in davis type filter material?The Campbell Sci tem/hum probe uses the 75.
https://www.campbellsci.com/cs215-l (click "read more")
I'd assume that probe filter housing is available somewhere in accessories or replacement parts.
The filter cap they use is https://www.campbellsci.com/p18142 and you request a quote. surely this isn't what most use is it? When they say request a quote it's beyond my price... :grin:
Most probes do use a filter similar to these. As far as the request a quote thing goes I think they just want you to sign up for an account. I have ordered several things from Campbell so I have one and can get online princing. The filter cap I planning on using is a replacement filter cap for a Vaisala HMP60 probe. Most of these run 20-45 dollars though they run up over $70 for the HMP155.
OK i am now running the 31 in the pro shield, it fits ok with the excess board removed so will watch it today and see how it goes. Everything looks good compared with the other sensors so far. It will be nice if everything goes well.
Something just came up from hwcorder post about using stock filter on modified 73. How about others? I don't see a specifically made filter for these so do they even require a filter? if so is it just some homebrew like wrapping sensor in davis type filter material?The Campbell Sci tem/hum probe uses the 75.
https://www.campbellsci.com/cs215-l (click "read more")
I'd assume that probe filter housing is available somewhere in accessories or replacement parts.
The filter cap they use is https://www.campbellsci.com/p18142 and you request a quote. surely this isn't what most use is it? When they say request a quote it's beyond my price... :grin:
Most probes do use a filter similar to these. As far as the request a quote thing goes I think they just want you to sign up for an account. I have ordered several things from Campbell so I have one and can get online princing. The filter cap I planning on using is a replacement filter cap for a Vaisala HMP60 probe. Most of these run 20-45 dollars though they run up over $70 for the HMP155.
What’s the advantages with that filter cap over Sensirion’s sf1 cap?
the winds were light so got a quick look at the difference between the two shields and the worst i saw was the standard ran at times about .9 degrees warmer The pro at the same time was running .4 degrees lower than the fars.
A man with a thermometer knows what the temperature is. A man with two thermometers is never sure. :idea:
Those tiny SF2 filters came in so wanted to practice installing with bad 31 sensor. Filter slid slightly no room for any error and ended up getting glue on 31. ](*,) Good thing it was a bad already.I just wrapped a thin braided wire around mine and cinched it down. With the rubbery base, I'm confident I have a waterproof seal. Now, whether I need that or not.....
Enough of that, going with original :idea:
Much safer method for me, just cut corner of stock Davis filter and using the universal eco glue supertite was able to safely add filter nice and tight as good as stock without the bulky filter body. Just ran small bead of glue (not thick) and works great. No smell or damaging chemicals with this glue and drys fast.
Doing a humidity test now. This was one of reconditioned 96% sensors just want to make sure it still reaches. It will be a spare for any of the passive shields if needed.
[ You are not allowed to view attachments ]
Something else for cutting these Davis sensor boards down if you have a set of metal tin snips very fast and clean cuts.
As of now (3:50PM EDT), about 2 hours after solar noon (1:55PM local time), winds average 2mph at 10m, skies are clear. FARS temp: 69.1 & 7714 temp: 73.1. This is typical of what I've been seeing and may even worsen in late afternoon when the sun angle is more directly focused on the western side of the passive shield.FARS rule. :-P ;)
[ You are not allowed to view attachments ]
Earlier this week I received and set up the Davis 7714 shield with a 31 sensor. It's about 8ft away and 1.5ft lower than my FARS (whose intake is at 5' 2").
This is the 3rd calm, sunny day in a row. Temps in the 70s mainly. Winds <3mph (~1 m/s) at 30ft (virtually calm at ground level).
I put some data into a spreadsheet and found that around solar noon the difference between the two shields averages around 3-3.5F, sometimes 4F or more (passive sensor running higher). Overall, the average daytime difference is about 2-2.5F. The only time the shields are within 1F during the midday and afternoon is when heavy clouds pass overhead.
The height differential between the shields may play some role. However, raising the shield a meter or so won't produce much additional wind because the measurement location (like so many backyard weather stations) is hemmed in by taller structures on multiple sides.
Overnight lows are a bit lower (0.5 - 1F) on clear nights in the 7714, but not enough to balance out the false highs. On nights when skies are cloudy and winds are greater than 3mph, the shields run within 0.5F of each other (within sensor's margin of error).
This is about the same performance as I was getting from the stock VP2 passive shield mounted in the same location. I'm hopeful, with just a bit more wind coming from a prevailing direction (rather than a sheltered direction), the 7714 will outperform the stock passive shield. Unfortunately, those conditions have yet to happen. And there's no end in sight to the days with 10m winds at or below 5mph.
WOW! Bad numbers there wonder why I'm getting much better results.
I'm reporting this passive aggressive post.As of now (3:50PM EDT), about 2 hours after solar noon (1:55PM local time), winds average 2mph at 10m, skies are clear. FARS temp: 69.1 & 7714 temp: 73.1. This is typical of what I've been seeing and may even worsen in late afternoon when the sun angle is more directly focused on the western side of the passive shield.FARS rule. :-P ;)
WOW! Bad numbers there wonder why I'm getting much better results.
Because of your optimal siting, even light winds will be felt to some degree at shield level. Not so much in my location. It's pretty safe to assume I have calm winds during most of the test period near ground level. I've walked around out there several times, looked up and seen the cups slowly turning at 30ft, but felt no breeze standing next to the shield.
If it's a new 31 did you remember to do the -.9 offset if using pre Jan 2016 transmitter. Only reason I ask is I have a mix of iss transmitters and have done exactly that before. :-)
Good idea. It gets even harder to keep track when switching between 31s and 75s.WOW! Bad numbers there wonder why I'm getting much better results.
Because of your optimal siting, even light winds will be felt to some degree at shield level. Not so much in my location. It's pretty safe to assume I have calm winds during most of the test period near ground level. I've walked around out there several times, looked up and seen the cups slowly turning at 30ft, but felt no breeze standing next to the shield.
If it's a new 31 did you remember to do the -.9 offset if using pre Jan 2016 transmitter. Only reason I ask is I have a mix of iss transmitters and have done exactly that before. :-)
Samething here...resorted to labelling the ISS covers "old" and "new" to keep things straight.
:-$I'm reporting this passive aggressive post.As of now (3:50PM EDT), about 2 hours after solar noon (1:55PM local time), winds average 2mph at 10m, skies are clear. FARS temp: 69.1 & 7714 temp: 73.1. This is typical of what I've been seeing and may even worsen in late afternoon when the sun angle is more directly focused on the western side of the passive shield.FARS rule. :-P ;)
Pictures of final position of shields and stuff.
:lol: Look who's talking... :lol:Pictures of final position of shields and stuff.
I think you need a couple more shields :grin:
OK i am now running the 31 in the pro shield, it fits ok with the excess board removed so will watch it today and see how it goes. Everything looks good compared with the other sensors so far. It will be nice if everything goes well.
My thought was it just allows you to put a slightly larger probe inside the shield without increasing the interior dimensions of the chamber. Could be there may be a slightly larger probe that is used that needs the slightly larger clamp.
The Pro is really looking like the real deal, especially for folks who don't want to mess with a fan (that won't be me).
It's obvious the Pro can handle it's own with a slight breeze, now the "no wind, lotsa sun" scenario is obviously needed for the "are fans obsolete" test. :-"
Saying this with tongue and cheek, is it possible the Davis shield does read low in low wind like the WMO study said? The Pro is following airport like they are cloned. #-o
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]
Saying this with tongue and cheek, is it possible the Davis shield does read low in low wind like the WMO study said? The Pro is following airport like they are cloned. #-o
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]
Probably so. The pro shield seems like the solution if you want to replace the FARS, more specifically, the Davis FARS. Planning on getting the pro shield soon.
Saying this with tongue and cheek, is it possible the Davis shield does read low in low wind like the WMO study said? The Pro is following airport like they are cloned. #-oWell then, the way I see it is that the Davis is more accurate just for this simple reason; how does a shield make the ambient air cooler than actually is??
Saying this with tongue and cheek, is it possible the Davis shield does read low in low wind like the WMO study said? The Pro is following airport like they are cloned. #-oWell then, the way I see it is that the Davis is more accurate just for this simple reason; how does a shield make the ambient air cooler than actually is??
Not saying it's not possible, I guess...
:eek: So the newcomers were seeing more sun than the two Davis shields before noon? Even after, kinda looks like the 7714 is saying "if it ain't broke, don't fix it. Very interesting...
Of course all you testers are ultimately doing this for your own benefits, but don't think that the members here aren't very appreciative of yours and the others time and money spent for the benefit of all interested parties. =D>:eek: So the newcomers were seeing more sun than the two Davis shields before noon? Even after, kinda looks like the 7714 is saying "if it ain't broke, don't fix it. Very interesting...I have too much invested to give up
I was about to bite on a Pro, but Randy's tests have given me pause.Of course all you testers are ultimately doing this for your own benefits, but don't think that the members here aren't very appreciative of yours and the others time and money spent for the benefit of all interested parties. =D>:eek: So the newcomers were seeing more sun than the two Davis shields before noon? Even after, kinda looks like the 7714 is saying "if it ain't broke, don't fix it. Very interesting...I have too much invested to give up
The Venturi effect, assuming its more than negligible, would apply to all shields since they restrict air flow greatly compared to the surrounding environment.Not that it's a measurable factor to our sensors, but not only, compressed air heats, not cools.
The Venturi effect, assuming its more than negligible, would apply to all shields since they restrict air flow greatly compared to the surrounding environment.Not that it's a measurable factor to our sensors, but not only, compressed air heats, not cools.
The Venturi effect, assuming its more than negligible, would apply to all shields since they restrict air flow greatly compared to the surrounding environment.Not that it's a measurable factor to our sensors, but not only, compressed air heats, not cools.
I believe the thinking with Venturi is that as a mass of air enters a constriction (inner chamber of shield in this instance), the pressure actually drops as it elongates. And I guess people are assuming that a drop in pressure corresponds to a drop in temperature? If this is true, then someone needs to explain why air expands as it warms and drops in pressure (unless constrained on all sides like in a pressure cooker).
Looks like other shields got dinged for running cooler also.
Looks like other shields got dinged for running cooler also.
According to that study, the author thinks the Davis passive is better than the Davis FARS...
Looks like other shields got dinged for running cooler also.
If the Pro is reading a warmer temp during the day then the RH should be lower since it's temp dependent. It was cooler at night too so the higher RH then makes sense as well. Do you have a graph of the dewpoints? I assume they're running neck and neck.
I made a correction on yesterday's numbers. Doesn't look as good.
Thanks for sharing Bobvelle. Yes I really at this point can't recommend the standard without additional shielding. Jerry's been working on that. :idea:
Sorry. I meant Meteoshield...thought you had the Pro version.If the Pro is reading a warmer temp during the day then the RH should be lower since it's temp dependent. It was cooler at night too so the higher RH then makes sense as well. Do you have a graph of the dewpoints? I assume they're running neck and neck.
Unfortunately no, I only have a DP graph for the primary (FARS) sensor. I am limited with my equipment.
But when you say "the Pro" do you mean the Davis Pro 2 or the Meteoshield Pro? Because I only have the Meteo Standard shield not the Pro version. And it was running higher temps but lower RH, which would correlate with your comment.
Sorry. I meant Meteoshield...thought you had the Pro version.If the Pro is reading a warmer temp during the day then the RH should be lower since it's temp dependent. It was cooler at night too so the higher RH then makes sense as well. Do you have a graph of the dewpoints? I assume they're running neck and neck.
Unfortunately no, I only have a DP graph for the primary (FARS) sensor. I am limited with my equipment.
But when you say "the Pro" do you mean the Davis Pro 2 or the Meteoshield Pro? Because I only have the Meteo Standard shield not the Pro version. And it was running higher temps but lower RH, which would correlate with your comment.
I made a correction on yesterday's numbers. Doesn't look as good.
Thanks for sharing Bobvelle. Yes I really at this point can't recommend the standard without additional shielding. Jerry's been working on that. :idea:
I don't have a Meteoshield Pro, so I don't know (Ha :-P).. But what is it about the design/construction of the Meteoshield Pro, In your opinion, that would make it a 'better' radiation shield than the standard version shield?
I know it's a smaller, narrower cavity and more louvers/gills, but is that the only difference?
That's some kind of bucket lid?
I used the lid of a 5 gal bucket as a Day FARS hanger a couple years ago. Worked pretty well.
I'll be interested to see the differences on a radiational cooling night. You're still running all 31s, correct?
Today was partly sunny here with a thin layer of clouds even when the sun shone. But we did get to the point where shadows were clearly visible for a couple hours - see data below. Not a perfect day for testing by any means but still meaningful.
As stated previously, I'm running the 7714 at 20ft and the 7755 FARS at 5ft. The test is mainly to see if there was an improvement from when the shield was near ground level (<4ft on my rain gauge post) in a sheltered location.
I can say absolutely there's been an improvement. I never saw agreement like this before. Even my wife noticed the difference which is hard to miss when you're accustomed to 2-4F differences during the daytime. I don't think I even saw a 1F departure at any time today.
It's all about the air flow!
Here are the average temperatures from 3PM - 5PM (avg wind: 2.3mph at 28ft):
FARS: 69.53F
7714: 69.85F
Difference: +0.31F (7714 warmer)
That's within the spec of the sensor so I would say they are even at this point.
For those curious about overnight differences, there were none. The lows were within 0.3F of each other (7714 slightly cooler); It was a cloudy night with very light breezes.
Looks like Friday is our first shot at decent sunshine. I'll report back then.
Sorry...that was meant for openvista.I'll be interested to see the differences on a radiational cooling night. You're still running all 31s, correct?
Yes still all 31's. Don't want to mix sensors right now these 31's are all within .1 of each other.
Sorry...that was meant for openvista.I'll be interested to see the differences on a radiational cooling night. You're still running all 31s, correct?
Yes still all 31's. Don't want to mix sensors right now these 31's are all within .1 of each other.
I know you had all of your sensors reading the same before your tests, but have you considered shifting the sensors into other shields?
I'll be interested to see the differences on a radiational cooling night. You're still running all 31s, correct?
It's all about the air flow!:shock:
The new look.
I know this screws the test up somewhat but I think I know how it would of went and like the fast response rate I see similar to fars unlike many passive units.
If all it takes is a top plate, plus maybe the standard version would work with something like this and everyone save a few $ over the pro.
The new look.
I know this screws the test up somewhat but I think I know how it would of went and like the fast response rate I see similar to fars unlike many passive units.
If all it takes is a top plate, plus maybe the standard version would work with something like this and everyone save a few $ over the pro.
I've been meaning to ask... WHAT'S UP WITH THOSE YELLOW ZIP-TIES :!: :?: Are they some kind of bird spikes?
Sorry. just a little OCD about uncut zip-ties :grin:
Randy, thank you for investing the time, money and effort to conduct these comparisons and then posting them for all of our benefit. Seeing your updates is like watching the next episode of my favorite series ...
If you don’t get the results you’re looking for in the passive shields, one thing you may want to consider if you think it’d be worth the effort is a little more separation between the shields to avoid one influencing the other and to promote airflow. When I did the side by side with the Davis FARS and the 7714, I initially had it set up as you do. I ended up getting better results with more separation (whether it was fan exhaust or airflow/solar shading I don’t know.) Not to say you’d get the same results, but just throwing it out there.
Today was rainy with 1.71" total spread out couple times during day. A few things I noticed was the 7714 does lag with the pro having quicker temperature changes. Even prior to rain last night the 7714 was behind about .5f.
Tonight the Pro has reached 98% humidity before 10pm which is max on sensor. The Fars 97% and 7714 96%.
[ You are not allowed to view attachments ]
Today was rainy with 1.71" total spread out couple times during day. A few things I noticed was the 7714 does lag with the pro having quicker temperature changes. Even prior to rain last night the 7714 was behind about .5f.
Tonight the Pro has reached 98% humidity before 10pm which is max on sensor. The Fars 97% and 7714 96%.
[ You are not allowed to view attachments ]
Let us know how high the humidity reaches too in the pro compared to the other shields in the morning. I’m liking what I’m hearing so far.
I find mine has to hit 98% early in the evening to have a chance at 99% or 100%. You've done a lot of reconditioning on the sensors recently so I'd be hesitant to make any assumptions on max potential RH between the different shields unless you swap some of the sensors around. Maybe just switch the FARS and Pro ones and see if the same thing happens again overnight after another wet day.
Beautiful sunny day almost zero wind at sensor level, should be the ultimate test day for what to expect in worse conditions for passive shield, no wind and sunny.
I did put the standard back up so all can see the performance and do have top shields over both Meteo. Not sure it really does much but why not.
I'll post graphs with wind speeds and solar information after peak temperatures later today. Test officially started at 12 noon Central so all shields were dry from the rain and none had any advantage.
Preview of current condition snapshot. Have no idea myself so will look later.
Be back later after peak temperatures, later.
[ You are not allowed to view attachments ]
Well, that's the rub. Some say it's because FARS makes the temp artificially low (which I think is a load of crap because of some of the ridiculous data), or it's low because it better at it's job.Beautiful sunny day almost zero wind at sensor level, should be the ultimate test day for what to expect in worse conditions for passive shield, no wind and sunny.
I did put the standard back up so all can see the performance and do have top shields over both Meteo. Not sure it really does much but why not.
I'll post graphs with wind speeds and solar information after peak temperatures later today. Test officially started at 12 noon Central so all shields were dry from the rain and none had any advantage.
Preview of current condition snapshot. Have no idea myself so will look later.
Be back later after peak temperatures, later.
[ You are not allowed to view attachments ]
FARS might be reading slightly cooler due to its design?
Beautiful sunny day almost zero wind at sensor level, should be the ultimate test day for what to expect in worse conditions for passive shield, no wind and sunny.
I did put the standard back up so all can see the performance and do have top shields over both Meteo. Not sure it really does much but why not.
I'll post graphs with wind speeds and solar information after peak temperatures later today. Test officially started at 12 noon Central so all shields were dry from the rain and none had any advantage.
Preview of current condition snapshot. Have no idea myself so will look later.
Be back later after peak temperatures, later.
[ You are not allowed to view attachments ]
The pro shield looks good. FARS might be reading slightly cooler due to its design? Davis passive either looks good because it’s good or there is lagging involved. If I were Barani, I would do away with the standard shield and just sell the pro.
Beautiful sunny day almost zero wind at sensor level, should be the ultimate test day for what to expect in worse conditions for passive shield, no wind and sunny.
I did put the standard back up so all can see the performance and do have top shields over both Meteo. Not sure it really does much but why not.
I'll post graphs with wind speeds and solar information after peak temperatures later today. Test officially started at 12 noon Central so all shields were dry from the rain and none had any advantage.
Preview of current condition snapshot. Have no idea myself so will look later.
Be back later after peak temperatures, later.
[ You are not allowed to view attachments ]
The pro shield looks good. FARS might be reading slightly cooler due to its design? Davis passive either looks good because it’s good or there is lagging involved. If I were Barani, I would do away with the standard shield and just sell the pro.
Think you'll like the test results on pro. Once again the rapid response to temperature change is really good. Just had first cloud which doesn't mess test up because we went through highest solar period cloud free with no wind.
Running almost a full degree under the lagging 7714. Still not low as fars but for wind free day not bad.
Peek
[ You are not allowed to view attachments ]
I don’t buy it either. Often when my 2m temp rots at 32F following a weak, overrunning FZRA system, my sensor continuously fluctuates between 31.9° and 32.1°. That’s what you would expect with no temperature advection while hovering at a phase change.Well, that's the rub. Some say it's because FARS makes the temp artificially low (which I think is a load of crap because of some of the ridiculous data), or it's low because it better at it's job.Beautiful sunny day almost zero wind at sensor level, should be the ultimate test day for what to expect in worse conditions for passive shield, no wind and sunny.
I did put the standard back up so all can see the performance and do have top shields over both Meteo. Not sure it really does much but why not.
I'll post graphs with wind speeds and solar information after peak temperatures later today. Test officially started at 12 noon Central so all shields were dry from the rain and none had any advantage.
Preview of current condition snapshot. Have no idea myself so will look later.
Be back later after peak temperatures, later.
[ You are not allowed to view attachments ]
FARS might be reading slightly cooler due to its design?
Just to show you my high temperature recorded by the fars at 2.23pm was 97.5F degrees and the pro at the same time showed 96.9F degrees. Just love it.Not that the Pro isn't stepping up to the plate, but as I stated before, I still think the FARS can be higher just for the simple fact it's always pulling air across the sensor and catching the higher temp the passive may be missing. Of course, that's just my theory.
I’m losing track of everyone’s setups, but he has just the stock fan too, correct?Just to show you my high temperature recorded by the fars at 2.23pm was 97.5F degrees and the pro at the same time showed 96.9F degrees. Just love it.Not that the Pro isn't stepping up to the plate, but as I stated before, I still think the FARS can be higher just for the simple fact it's always pulling air across the sensor and catching the higher temp the passive may be missing. Of course, that's just my theory.
So if i can get some relief from the cleaning chores and not have to mess with fans and power i am sold completely on the pro until it lets me down lol.Absolutely! I deal with a filthy sensor chamber too, but not enough for me to abandon my fan. If I didn't already have my current setup well established, I might have actually tried this.
Just as a further thought, this is exactly why ASOS's use an averaging algorithm, to eliminate the high and low spikes that we aspirated PWS folks take for granted.I think the 5-min running averages best mimicked Hg thermometers. So when these stations went from max/min liquid-filled thermometers to aspirated probes they needed the averaging to maintain consistency with the climo record.
I'm sure all of us have seen our temp go up a degree or whatever for a packet cycle, then never to be seen again, that's our high. An ASOS would never report such a thing as valid, only as a number to be averaged in it's determined cycle.Good stuff here...
Indeed, read the whole thing. I certainly remember the HO-83 fiasco here in the early nineties, even the Chamber of Commerce got involved.I'm sure all of us have seen our temp go up a degree or whatever for a packet cycle, then never to be seen again, that's our high. An ASOS would never report such a thing as valid, only as a number to be averaged in it's determined cycle.Good stuff here...
https://training.weather.gov/nwstc/DATAACQ/d.ASOShuman/Temp.htm
Indeed, read the whole thing. I certainly remember the HO-83 fiasco here in the early nineties, even the Chamber of Commerce got involved.I'm sure all of us have seen our temp go up a degree or whatever for a packet cycle, then never to be seen again, that's our high. An ASOS would never report such a thing as valid, only as a number to be averaged in it's determined cycle.Good stuff here...
https://training.weather.gov/nwstc/DATAACQ/d.ASOShuman/Temp.htm
Makes me love my well aspirated PWS even more.
If you are asking me yes the fars is a stock davis set up other than i am running the fan off of a walwart at 2.3 volts during the day and 1 volt at night using a photocell and relay setup.
Took me awhile to find...here ya go.Indeed, read the whole thing. I certainly remember the HO-83 fiasco here in the early nineties, even the Chamber of Commerce got involved.I'm sure all of us have seen our temp go up a degree or whatever for a packet cycle, then never to be seen again, that's our high. An ASOS would never report such a thing as valid, only as a number to be averaged in it's determined cycle.Good stuff here...
https://training.weather.gov/nwstc/DATAACQ/d.ASOShuman/Temp.htm
Makes me love my well aspirated PWS even more.
If I remember correctly it wasnt due to lack of aspiration the problem more associated with exhaust air being recirculated back through the HO-83. Air being deflected down from the top rounded dome at the top of the shield was then getting sucked back into the intake at the bottom. Every time this happened the air was warmed little by little. This is why they added the fin towards the bottom of the shield to deflect air to the side preventing recirculation.
Just me, but I still think this is a complete waste of time. Let'er rip.If you are asking me yes the fars is a stock davis set up other than i am running the fan off of a walwart at 2.3 volts during the day and 1 volt at night using a photocell and relay setup.
What are you using after the relay switches to reduce the voltage?
Therefore, many more studies finding aspirated shields are "disappointing" compared to passive shields in high insolation, low wind situations are necessary before I'd buy in.+1 There's not enough convoluted evidence on this planet that could convince me that a passive shield would out perform an aspirated shield in my climate when your skin will burn in literal minutes and the wind is calm.
Well great test day with wind speed very low 0 mph much of day, sunny except maybe 2 clouds all day.As always Randy.... =D>
This is what can be expected on worse day passive vs FARS.
Both Meteoshields have additional top shield. I'm little skeptical of how well it helps at this latitude but it did provide partial shade most of day. That of course ends as we go into winter and top cover does little shading. As stated several times the Meteoshields have good response for fars they really leave the 7714 in the dust.
I can't recommend the Standard even at price point. Not horrible but I would spend money on the better 7714 before the standard.
The PRO is better than the 7714 imo so plan on adding second unit if they take the standard shield back. Still no response from them on returning. Maybe they didn't like what I said about it. Just it didn't meet my expectations...What's wrong with that? :lol:
Anyone getting one of these shields I recommend the 30' sensor just because the Davis plugs are so short. I do think Jerry said he got one working with stock setup but not 100% on that.
You will need to cut down the sensor to fit inside the Pro shield. I just used tin snips. For filter I used low VOC glue and just glued on using one corner of Davis filter. The glue I used easily pulls off later for changing. One stock Davis filter gives 4 filter changes.
Broke down FARS against each shield for cleaner comparision
Well great test day with wind speed very low 0 mph much of day, sunny except maybe 2 clouds all day.As always Randy.... =D>
This is what can be expected on worse day passive vs FARS.
Both Meteoshields have additional top shield. I'm little skeptical of how well it helps at this latitude but it did provide partial shade most of day. That of course ends as we go into winter and top cover does little shading. As stated several times the Meteoshields have good response for fars they really leave the 7714 in the dust.
I can't recommend the Standard even at price point. Not horrible but I would spend money on the better 7714 before the standard.
The PRO is better than the 7714 imo so plan on adding second unit if they take the standard shield back. Still no response from them on returning. Maybe they didn't like what I said about it. Just it didn't meet my expectations...What's wrong with that? :lol:
Anyone getting one of these shields I recommend the 30' sensor just because the Davis plugs are so short. I do think Jerry said he got one working with stock setup but not 100% on that.
You will need to cut down the sensor to fit inside the Pro shield. I just used tin snips. For filter I used low VOC glue and just glued on using one corner of Davis filter. The glue I used easily pulls off later for changing. One stock Davis filter gives 4 filter changes.
Broke down FARS against each shield for cleaner comparision
I to tried resistors but way too much variations in voltage so i just used the drop across a silcon diode at .7 volts. I had a 3 volt wallwart and put 3 diode in series which gave me a volt for night time use and the relay at night is basically not in use then in the am the photocell pulls the relay closed and i use a set of normal open contacts that close when the relay pulls and shorts out 2 of the diodes of the 3 that are in series which gives me just one diode for a voltage of 2.3 volts for daytime running.
Broke down FARS against each shield for cleaner comparision
[ You are not allowed to view attachments ]
Broke down FARS against each shield for cleaner comparision
[ You are not allowed to view attachments ]
Great Info!
Are the temps at the top the Average or standard deviation or...?
It Looks like my standard Meteo is doing about as good as your Pro...I'm only getting 1.5 -2 deg difference in the sun too Hmm
i don't have extreme heatheh. I think 99% of the forum had to laugh at that one. ;)
Broke down FARS against each shield for cleaner comparision
[ You are not allowed to view attachments ]
Great Info!
Are the temps at the top the Average or standard deviation or...?
It Looks like my standard Meteo is doing about as good as your Pro...I'm only getting 1.5 -2 deg difference in the sun too Hmm
Here is one to ponder everyone. The KVTN ASOS 1.3 mi distance, High was 87.1° today. That's still 2° warmer than the warmest shield (Standard).
So any of these shields looked stellar when comparing with the ASOS FARS #-o
So the hard sucking FARS doesn’t matter, geography really makes the big difference. I'm sure I have my own summer micro climate with all the vegetation.
That's still 2° warmer than the warmest shield (Standard).Well, not if they were side by side. I mean, you yourself verified the ASOS temp was spot on accurate only 2 or 3 weeks ago, right?
So any of these shields looked stellar when comparing with the ASOS FARS #-o
Update I was asked if I would continue testing all shields for long term study.Tell them you'd be glad to, but you need one of their temp/hum probes free of charge too. ;)
So guess I’ll set up the shields a little different instead of using tripod I need a permanent setup.
Another project and yes I enjoy stuff like this as you can imagine.
Heard back from Allmeteo and got refunded for standard. Sent them all my data in CVS form from test.
Also ordered a second Pro unit for remote site.
I do think the Pro is as good as any passive shield can get even surpassing the highly regarded 7714.
Those that have a breeze like Jerry living on the Gulf will never miss the FARS. If you are in the desert I wouldn't change over however.
Update I was asked if I would continue testing all shields for long term study.Tell them you'd be glad to, but you need one of their temp/hum probes free of charge too. ;)
So guess I’ll set up the shields a little different instead of using tripod I need a permanent setup.
Another project and yes I enjoy stuff like this as you can imagine.
Heard back from Allmeteo and got refunded for standard. Sent them all my data in CVS form from test.
Also ordered a second Pro unit for remote site.
I do think the Pro is as good as any passive shield can get even surpassing the highly regarded 7714.
Those that have a breeze like Jerry living on the Gulf will never miss the FARS. If you are in the desert I wouldn't change over however.
It actually looks like they use the SHT75 based on the specs. +/- 1.8% RH is usually a dead giveaway.
Broke down FARS against each shield for cleaner comparision
[ You are not allowed to view attachments ]
Great Info!
Are the temps at the top the Average or standard deviation or...?
It Looks like my standard Meteo is doing about as good as your Pro...I'm only getting 1.5 -2 deg difference in the sun too Hmm
Well, what's your wind like? Looks like Randy hit a max of 2mph the entire test period today! That's about as good as it gets for testing shields. If there were any errors to be found, they'd be sure to show up.
EDIT: missed that you posted 1.5mph avg wind. Randy didn’t give an average but his appears to be lower just looking at his graph. That might explain the discrepancy.
His does "look" closer, but then again, his index lines are 5 deg apart. :-)
I'm not making the claim that the standard is just as good as the Pro... I was just surprised that the standard did that well in my comparative test.
Agreed. But the only thing I know of that would not allow ANY heat (radiation) from affecting the enclosed sensor in stagnate air environment would be a lead lined vacuum chamber. Heat is going to find its way in to affect the reading no matter how well it's made, if there is little to no wind. So does a "good" radiation shield even exist?His does "look" closer, but then again, his index lines are 5 deg apart. :-)
I'm not making the claim that the standard is just as good as the Pro... I was just surprised that the standard did that well in my comparative test.
IMO, a solar radiation shield that doesn't perform well in the sun is a bad solar radiation shield.
Average wind speed was really low yesterday, highest I saw was .2 MPH and not much better today.Looks like Davis HQ. lol
New setup image. Concrete is still drying, the standard shield needs straightened after it dries little more.
[ You are not allowed to view attachments ]
I'll take a look see if I figure out what you see.Average wind speed was really low yesterday, highest I saw was .2 MPH and not much better today.Looks like Davis HQ. lol
New setup image. Concrete is still drying, the standard shield needs straightened after it dries little more.
[ You are not allowed to view attachments ]
In the pics of the shields I see on their site, it looks like the "gills" slope downward from the mounting bracket outward. Yours seem to be in the opposite direction, sloping upward. Is it possible to switch them around 180 degrees so that they're sloping downward toward the south side? Maybe it wouldn't make a difference...just an idea. I'm assuming your mounting arms are already aiming S based on the shadows in your pic.
The gills slope downward from the mounting bracket side in these images.I'll take a look see if I figure out what you see.Average wind speed was really low yesterday, highest I saw was .2 MPH and not much better today.Looks like Davis HQ. lol
New setup image. Concrete is still drying, the standard shield needs straightened after it dries little more.
[ You are not allowed to view attachments ]
In the pics of the shields I see on their site, it looks like the "gills" slope downward from the mounting bracket outward. Yours seem to be in the opposite direction, sloping upward. Is it possible to switch them around 180 degrees so that they're sloping downward toward the south side? Maybe it wouldn't make a difference...just an idea. I'm assuming your mounting arms are already aiming S based on the shadows in your pic.
Agreed. But the only thing I know of that would not allow ANY heat (radiation) from affecting the enclosed sensor in stagnate air environment would be a lead lined vacuum chamber. Heat is going to find its way in to affect the reading no matter how well it's made, if there is little to no wind. So does a "good" radiation shield even exist?His does "look" closer, but then again, his index lines are 5 deg apart. :-)
I'm not making the claim that the standard is just as good as the Pro... I was just surprised that the standard did that well in my comparative test.
IMO, a solar radiation shield that doesn't perform well in the sun is a bad solar radiation shield.
I honestly don't know..just asking the question.
The gills slope downward from the mounting bracket side in these images.I'll take a look see if I figure out what you see.Average wind speed was really low yesterday, highest I saw was .2 MPH and not much better today.Looks like Davis HQ. lol
New setup image. Concrete is still drying, the standard shield needs straightened after it dries little more.
[ You are not allowed to view attachments ]
In the pics of the shields I see on their site, it looks like the "gills" slope downward from the mounting bracket outward. Yours seem to be in the opposite direction, sloping upward. Is it possible to switch them around 180 degrees so that they're sloping downward toward the south side? Maybe it wouldn't make a difference...just an idea. I'm assuming your mounting arms are already aiming S based on the shadows in your pic.
https://www.allmeteo.com/meteo-shop/?category=Temperature
The gills slope downward from the mounting bracket side in these images.I'll take a look see if I figure out what you see.Average wind speed was really low yesterday, highest I saw was .2 MPH and not much better today.Looks like Davis HQ. lol
New setup image. Concrete is still drying, the standard shield needs straightened after it dries little more.
[ You are not allowed to view attachments ]
In the pics of the shields I see on their site, it looks like the "gills" slope downward from the mounting bracket outward. Yours seem to be in the opposite direction, sloping upward. Is it possible to switch them around 180 degrees so that they're sloping downward toward the south side? Maybe it wouldn't make a difference...just an idea. I'm assuming your mounting arms are already aiming S based on the shadows in your pic.
https://www.allmeteo.com/meteo-shop/?category=Temperature
I picked the 16" pizza pan up at dollar general cheap.Pizza pan... :???:
I had trouble keeping my meteo bracket stable with just one U-bolt. Had to use 2, I guess your not having an issue with it?
So your still going to be testing the standard? Thought you were going to give up on it.
So you're shielding their shield....I had trouble keeping my meteo bracket stable with just one U-bolt. Had to use 2, I guess your not having an issue with it?16” diameter shield
So your still going to be testing the standard? Thought you were going to give up on it.
They have all the typical data so I’m giving data that’s unusual.
So you're shielding their shield....I had trouble keeping my meteo bracket stable with just one U-bolt. Had to use 2, I guess your not having an issue with it?16” diameter shield
So your still going to be testing the standard? Thought you were going to give up on it.
They have all the typical data so I’m giving data that’s unusual.
Kinda defeats the purpose of what it's suppose to be in the first place isn't it, a competent shield?
So you're shielding their shield....I had trouble keeping my meteo bracket stable with just one U-bolt. Had to use 2, I guess your not having an issue with it?16” diameter shield
So your still going to be testing the standard? Thought you were going to give up on it.
They have all the typical data so I’m giving data that’s unusual.
Kinda defeats the purpose of what it's suppose to be in the first place isn't it, a competent shield?
What did I just say? I'm doing what I want, if I can make it better, I will. I don't care about their stock shield. Everything can be improved.
The 7714 is no longer stock. It performs better with black inside.
The FARS is no longer stock with the AC fan. Even my Cocorahs gauge is better than the original design with the deeper funnel. I don’t like anything stock. Cars, trucks, ATV’s first thing I do is start making it better.
I tried that on my wife too, but didn’t go over well… ;)