Author Topic: Barometer 'Sanity Check', how to...  (Read 6620 times)

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Offline Old Tele man

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Barometer 'Sanity Check', how to...
« on: November 06, 2016, 03:29:18 PM »
I recently replaced/upgraded my 4-year old Davis VP2 console with a new Vue console. That meant a new barometer sensor was being used. Although the new barometer readings did not seem to change much, I wanted to *KNOW* they were OK. So, I decided to do a 'Sanity Check' to prove (to myself) that the pressure readings were (a) reasonable and (b) how close/far they were to expectations.

The attached PDF documents my process and results.

Discuss ( all comments / critique / suggestions / improvements welcomed ).
« Last Edit: June 27, 2018, 08:56:05 AM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX2 & DBX1 Precision Digital Barographs
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #1 on: November 06, 2016, 03:43:16 PM »
Although the new barometer readings did not seem to change much, I wanted to *KNOW* they were OK.
Looks good. You won't see a lot of change until the altimeter gets quite high or low. That's where the Vue keeps up and the VP2 begins losing ground. Sit the two together and observe as I did, you'll begin to see the subtleties.

Offline PaulMy

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Re: Barometer 'Sanity Check', how to...
« Reply #2 on: November 06, 2016, 04:43:34 PM »

Well that attachment reading checked my sanity #-o


Seriously, well done =D>


Paul

Offline Old Tele man

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Re: Barometer 'Sanity Check', how to...
« Reply #3 on: November 06, 2016, 04:48:34 PM »
Although the new barometer readings did not seem to change much, I wanted to *KNOW* they were OK.
Looks good. You won't see a lot of change until the altimeter gets quite high or low. That's where the Vue keeps up and the VP2 begins losing ground. Sit the two together and observe as I did, you'll begin to see the subtleties.
To be honest, I replaced the VP2 console with the Vue console because of reception/drop-out problems with the VP2, not because of pressure readings.

Between 07/22/15 and 10/30/16, the VP2 console experienced 21 episodes of total ISS signal drop-outs. In earlier years, I'd see one, maybe two, drop-outs a year, but starting in 2015, they began to occur increasingly more often. And, all (I believe) were RX problems, not really ISS TX problems -- I know this because data saved by my concurrently operating Envoy8X, which simultaneously receives its data from the same VP2 ISS, did not contain any drop-outs.

Davis makes GOOD equipment, but it certainly is NOT perfect equipment...I wouldn't trust them to make my pacemaker (wink,wink)!
« Last Edit: October 02, 2017, 12:09:59 PM by Old Tele man »
SYS: Davis VP2 Vue/WL-IP & Envoy8X/WL-USB;
DBX2 & DBX1 Precision Digital Barographs
CWOP: DW6988 - 2 miles NNE of Cortaro, AZ
WU - KAZTUCSO202, Countryside

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #4 on: November 06, 2016, 05:07:44 PM »
Although the new barometer readings did not seem to change much, I wanted to *KNOW* they were OK.
Looks good. You won't see a lot of change until the altimeter gets quite high or low. That's where the Vue keeps up and the VP2 begins losing ground. Sit the two together and observe as I did, you'll begin to see the subtleties.
To be honest, I replaced the VP2 console with the Vue console because of reception/drop-out problems with the VP2, not because of pressure readings.
Understood. Hopefully this will solve your big problem and certainly get you an accurate altimeter setting at the same time.

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #5 on: November 06, 2016, 05:55:26 PM »

Well that attachment reading checked my sanity #-o
Paul
That's why I just looked at the pictures. :-?

Offline DanS

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Re: Barometer 'Sanity Check', how to...
« Reply #6 on: November 06, 2016, 06:23:18 PM »

Well that attachment reading checked my sanity #-o
Paul
That's why I just looked at the pictures. :-?
ditto, since there's a reliable source (airport) nearby I routinely use CWOP's findU/Quality control graph comparison page, select the airport (VTCC) to compare with and the picture tells the story. [ You are not allowed to view attachments ]

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #7 on: November 06, 2016, 06:39:51 PM »

Well that attachment reading checked my sanity #-o
Paul
That's why I just looked at the pictures. :-?
ditto, since there's a reliable source (airport) nearby I routinely use CWOP's findU/Quality control graph comparison page, select the airport (VTCC) to compare with and the picture tells the story. [ You are not allowed to view attachments ]
How did you do that, compare yourself against another sole particular source? All I've ever seen is all stations compared against the "analysis" of ones self.

Offline Scalphunter

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Re: Barometer 'Sanity Check', how to...
« Reply #8 on: November 06, 2016, 06:59:38 PM »
Check 1 box at the bottom of the page  but in all reality Findu is an joke. One day here next day off the coast of Africa and  very bad analysis for me due  to inverision layers.

John

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #9 on: November 06, 2016, 07:00:40 PM »
I don't know what value to set mine at here. I have the luxury of having one NWS reporting station 20 miles away and another one about 6 miles away but their pressure data never jives.
Right now the one 20 miles NW of me is at 30.08.
The one 6 miles SE of me is at 29.98.
I am at 30.10 after just yesterday setting it to the station north of me because on CWOP's QC I am lower then everyone else. Go figure.
By the way we're all at about 75 feet.
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Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #10 on: November 06, 2016, 07:03:10 PM »

Well that attachment reading checked my sanity #-o
Paul
That's why I just looked at the pictures. :-?
ditto, since there's a reliable source (airport) nearby I routinely use CWOP's findU/Quality control graph comparison page, select the airport (VTCC) to compare with and the picture tells the story. [ You are not allowed to view attachments ]
How did you do that, compare yourself against another sole particular source? All I've ever seen is all stations compared against the "analysis" of ones self.
At the bottom where it has the other stations listed check the box next to one of them and at the bottom click Add To Charts.
The blues had a baby and they named it Rock & Roll

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #11 on: November 06, 2016, 07:13:38 PM »
I don't know what value to set mine at here. I have the luxury of having one NWS reporting station 20 miles away and another one about 6 miles away but their pressure data never jives.
Right now the one 20 miles NW of me is at 30.08.
The one 6 miles SE of me is at 29.98.
I am at 30.10 after just yesterday setting it to the station north of me because on CWOP's QC I am lower then everyone else. Go figure.
By the way we're all at about 75 feet.
OCF is at 30.18, which is an AWOS. You should be very close to this.

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #12 on: November 06, 2016, 07:18:06 PM »

Well that attachment reading checked my sanity #-o
Paul
That's why I just looked at the pictures. :-?
ditto, since there's a reliable source (airport) nearby I routinely use CWOP's findU/Quality control graph comparison page, select the airport (VTCC) to compare with and the picture tells the story. [ You are not allowed to view attachments ]
How did you do that, compare yourself against another sole particular source? All I've ever seen is all stations compared against the "analysis" of ones self.
At the bottom where it has the other stations listed check the box next to one of them and at the bottom click Add To Charts.
I see "other stations", but no box to check or add to charts, never have.

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #13 on: November 06, 2016, 07:23:31 PM »
Go to quality control graphs.
Then go to the bottom of that page.
The blues had a baby and they named it Rock & Roll

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #14 on: November 06, 2016, 07:25:36 PM »
I don't know what value to set mine at here. I have the luxury of having one NWS reporting station 20 miles away and another one about 6 miles away but their pressure data never jives.
Right now the one 20 miles NW of me is at 30.08.
The one 6 miles SE of me is at 29.98.
I am at 30.10 after just yesterday setting it to the station north of me because on CWOP's QC I am lower then everyone else. Go figure.
By the way we're all at about 75 feet.
OCF is at 30.18, which is an AWOS. You should be very close to this.
OK I'm confused. Certainly not the first time. :roll:
In Weatherlink, setting the barometer what do I put in the sea level barometer. Altimeter setting?
The blues had a baby and they named it Rock & Roll

Offline Scalphunter

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Re: Barometer 'Sanity Check', how to...
« Reply #15 on: November 06, 2016, 07:26:15 PM »
From the Findu you  page goto the next page that has your data.  Not the one that has your station on the maps. It be one where you are compare to others  and separate page to compare to locals. Be 2 different clickables at top of page.

John

Offline Scalphunter

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Re: Barometer 'Sanity Check', how to...
« Reply #16 on: November 06, 2016, 07:28:43 PM »
if you at sea level  or close to it seeing how in Flordia the highest thing on av charts are the garbage dumps yes.

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #17 on: November 06, 2016, 07:29:16 PM »
I don't know what value to set mine at here. I have the luxury of having one NWS reporting station 20 miles away and another one about 6 miles away but their pressure data never jives.
Right now the one 20 miles NW of me is at 30.08.
The one 6 miles SE of me is at 29.98.
I am at 30.10 after just yesterday setting it to the station north of me because on CWOP's QC I am lower then everyone else. Go figure.
By the way we're all at about 75 feet.
OCF is at 30.18, which is an AWOS. You should be very close to this.
OK I'm confused. Certainly not the first time. :roll:
In Weatherlink, setting the barometer what do I put in the sea level barometer. Altimeter setting?
Do you have a Vue or VP2 console?

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #18 on: November 06, 2016, 07:30:02 PM »
VP2
The blues had a baby and they named it Rock & Roll

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #19 on: November 06, 2016, 07:38:23 PM »
VP2
OK. The VP2 does not calculate the altimeter as does the Vue. If you want to be as close to OCF as you can set your console altitude to ZERO and dial in their altimeter setting, preferably in "benign-ish" conditions and around 29.85 to 30.00, if you can. Won't be completely accurate, but close, except for somewhat higher and lower pressures.

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #20 on: November 06, 2016, 07:51:51 PM »
VP2
OK. The VP2 does not calculate the altimeter as does the Vue. If you want to be as close to OCF as you can set your console altitude to ZERO and dial in their altimeter setting, preferably in "benign-ish" conditions and around 29.85 to 30.00, if you can. Won't be completely accurate, but close, except for somewhat higher and lower pressures.
Thank you!
OCF to my north is at 30.20 while VVG to my south is at 30.09. Probably split the difference.
The blues had a baby and they named it Rock & Roll

Offline CW2274

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Re: Barometer 'Sanity Check', how to...
« Reply #21 on: November 06, 2016, 08:05:15 PM »
VP2
OK. The VP2 does not calculate the altimeter as does the Vue. If you want to be as close to OCF as you can set your console altitude to ZERO and dial in their altimeter setting, preferably in "benign-ish" conditions and around 29.85 to 30.00, if you can. Won't be completely accurate, but close, except for somewhat higher and lower pressures.
Thank you!
OCF to my north is at 30.20 while VVG to my south is at 30.09. Probably split the difference.
Lean towards the closer one.
If you want and have a few extra bucks, get a Vue, then you know it's right no matter where you're at. Complete comparison then, especially when WX moves through!

Offline ValentineWeather

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Re: Barometer 'Sanity Check', how to...
« Reply #22 on: November 06, 2016, 08:50:04 PM »
VP2
OK. The VP2 does not calculate the altimeter as does the Vue. If you want to be as close to OCF as you can set your console altitude to ZERO and dial in their altimeter setting, preferably in "benign-ish" conditions and around 29.85 to 30.00, if you can. Won't be completely accurate, but close, except for somewhat higher and lower pressures.
Thank you!
OCF to my north is at 30.20 while VVG to my south is at 30.09. Probably split the difference.

I only see 2 near you I would trust. Both airports currently 30.21 and 30.20

http://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KOCF&unit=0&timetype=LOCAL
http://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KLEE&unit=0&timetype=LOCAL
Randy

Offline ocala

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Re: Barometer 'Sanity Check', how to...
« Reply #23 on: November 06, 2016, 08:58:51 PM »
VP2
OK. The VP2 does not calculate the altimeter as does the Vue. If you want to be as close to OCF as you can set your console altitude to ZERO and dial in their altimeter setting, preferably in "benign-ish" conditions and around 29.85 to 30.00, if you can. Won't be completely accurate, but close, except for somewhat higher and lower pressures.
Thank you!
OCF to my north is at 30.20 while VVG to my south is at 30.09. Probably split the difference.

I only see 2 near you I would trust. Both airports currently 30.21 and 30.20

http://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KOCF&unit=0&timetype=LOCAL
http://mesowest.utah.edu/cgi-bin/droman/meso_base_dyn.cgi?stn=KLEE&unit=0&timetype=LOCAL
I started checking all the reporting stations in the area and they are all in the 30.20 to 30.22 range except for KVVG which is at 30.10. Obviously that data is incorrect. Sent an email off to the the KJAX weather office that they need to fix that problem.
Anyways I am a happy camper because my pressure is pretty accurate. :-)
The blues had a baby and they named it Rock & Roll

Offline ValentineWeather

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Re: Barometer 'Sanity Check', how to...
« Reply #24 on: November 06, 2016, 09:08:58 PM »
Good deal  =D>
Randy

 

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