Author Topic: Explaining differences between shields  (Read 945 times)

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Offline hmderek

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Explaining differences between shields
« on: August 19, 2021, 05:21:24 AM »
This week I added the Apogee Instruments TS-100 fan aspirated shield to my setup. Readings from the shield are not exactly what I expected. I'm trying to make sense of the initial data I am getting. Should get some fun out of figuring this out.  :grin:

I am comparing 4 shields.

2x Barani MeteoShield Pro with the same SHT35 sensor probe from the same seller
1x Davis 7714 with a steel SHT35 probe
1x Apogee TS-100 with the same probe casing as the Barani's, but the SHT35 comes from a different seller

What I am seeing is this. During the night the TS-100 reads a bit lower at times than my other sensors in passive shields. Makes sense, I am guessing. I am hoping it's due to the fact that during the night there's hardly any wind and the ventilated sensor reacts better to dropping temperatures while the passive shields retain slightly more warmth due to lack of ventilation.

Below you can see the graph as it's developing today. It's a rainy day, and only after 10AM does the radiation actually exceed 100 W/m2, though it hasn't hit 200 yet. At that point temperatures start to rise, and I note that the Apogee along with the 7714 start rising quicker than the Barani's. 0.2 degrees higher at points now. Yesterday saw a similar pattern, up to 0.5 degrees higher for the Apogee and 7714 at times. And that under mostly moderate radiation.

Now I am concerned about the Apogee. What could explain the apparent deviation? I am thinking a few things:

- Could it be the fact that the Apogee is open at the bottom and the sensor casing (see below) is warmed slightly by reflected radiation?

- Could it be that the fan sucks air from below that it actually receives air from closer to the ground and therefore a bit warmer?

- Could it be that the sensors reacts differently somehow?

- Could it be that the Barani's are not as responsive is some way?

Other theories?

I've recently come to assume that the Barani's give me very good readings under average conditions, because the results match up very good on average with a nearby station of our Met Office.

 [ You are not allowed to view attachments ]
The TS-100 from below.
 [ You are not allowed to view attachments ]
« Last Edit: August 19, 2021, 05:36:06 AM by hmderek »
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline hmderek

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Re: Explaining differences between shields
« Reply #1 on: August 19, 2021, 06:05:31 AM »
I might add that when I include the graph for the Davis SHT31, after the lines deviate there seems to be some agreement between the yellow, green and red lines (Davis VP2, Apogee, 7714) on the one side and the two Barani's (blue and purple) on the other.

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Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline hmderek

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Re: Explaining differences between shields
« Reply #2 on: August 19, 2021, 09:20:12 AM »
It's been raining (more like drizzling) on and off today.

Something I've noticed before is the responsiveness of the 7714 (in red). Not just with warming but with cooling too. This may be due (in part?) to the different probe type (steel probe vs plastic).

What I'm now also noticing is that the Apogee and 7714 appear to be in agreement a lot compared to the two Barani's. Perhaps the Apogee cools a bit more (especially after 13.00 when I forced the setting to 100% fan speed).


 [ You are not allowed to view attachments ]
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline Ivan13

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Re: Explaining differences between shields
« Reply #3 on: August 19, 2021, 05:13:29 PM »
A hypothesis could be that the sensor is too big and this reduces the flow rate of the air it can suck in. Maybe you should opt for much smaller probes, if you also see, the probe that is often used with the apogee is a very small probe !! This for example:

The difference between sensor with metal and plastic cap also makes the difference, here for example a comparison that I made some time ago between two identical standard barani with which I did various tests, including that between metal probe and plastic probe: find something here https://www.wxforum.net/index.php?topic=40562.0
« Last Edit: August 19, 2021, 05:16:49 PM by Ivan13 »
1. Froggit HP1000SE PRO;
2. GATEWAY GW1003 (ws80/wh40/wh32-ep in barani standard)
3. GATEWAY WH2650 (3rd station)(1 WH32-EP METAL, 1 WH40)
6. LIGHTING SENSOR;
7. OTHERS WH31 NORMAL and 1 WH31-EP
8. RAIN SENSOR;
9. WEBCAM HP10 (beta test)
10. LOW COST STATION (WN1900).

Offline zoomx

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Re: Explaining differences between shields
« Reply #4 on: August 20, 2021, 03:55:46 AM »
Before testing you should put all sensors in an insulated box and measure for hours so you can estimate the differences between sensors due to small differences during manifacturing.

I also agree with @Ivan13, sensor dimensions may reduce the air volume inside the shield. Datasheet may report the maximum sensor dimension.

Offline hmderek

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Re: Explaining differences between shields
« Reply #5 on: August 20, 2021, 07:25:12 AM »
I will be trying a different probe inside the Apogee.

I must say, it absolutely strikes me how well the 7714 and the Apogee match up. Two different screens with different probe types seem to agree with each other completely. The 2 Barani shields agree too.

Makes me really wonder if the problem is with the sensors inside the Barani shields. Will definitely be testing this!

 [ You are not allowed to view attachments ]
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #6 on: August 20, 2021, 07:45:55 AM »
It's been raining (more like drizzling) on and off today.

Something I've noticed before is the responsiveness of the 7714 (in red). Not just with warming but with cooling too. This may be due (in part?) to the different probe type (steel probe vs plastic).

What I'm now also noticing is that the Apogee and 7714 appear to be in agreement a lot compared to the two Barani's. Perhaps the Apogee cools a bit more (especially after 13.00 when I forced the setting to 100% fan speed).


 [ You are not allowed to view attachments ]

you could improve the performance of the davis7714, by changing the position of the wh31 ep sensor inside
 [ You are not allowed to view attachments ]
try to put it as it is in the photo next to the graphs, Davis recommends that position in the Davis 7714;) as regards the apoge TS-100 it needs a small sensor, already removing the plastic on the sht-35 sensor of the wh31 ep things get better  [tup]
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #7 on: August 21, 2021, 06:07:50 AM »
What a complete reversal of the situation today!

This morning started with foggy conditions. A similar pattern evolved. The two Barani's on the one side, 7714 and Apogee on the other.

Right up until 11 AM.

Then the sun came out, and radiation spiked to 800 W/m2 quickly. On top of that, there is no wind at all at sensor level. Anemometer at 1.8m is not moving.

The 7714 and Apogee start to deviate and the Apogee joins the Barani's for half an hour, after which the lack of ventilation apparently starts to hurt the Barani's too.

This is super interesting, albeit confusing. Going to keep an eye on this as it develops today. Hope winds pick up a bit to see how that affects readings.

 [ You are not allowed to view attachments ]
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline hmderek

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Re: Explaining differences between shields
« Reply #8 on: August 22, 2021, 08:02:50 AM »
More revelations for me today.

Last evening I changed the probe in my second Barani. I removed the plastic probe and replaced it with this steel probe:
 [ You are not allowed to view attachments ]

It's the same probe I use in the 7714.

The result? This is the graph from this morning, 08:00 to 11:00.

 [ You are not allowed to view attachments ]

Suddenly the second Barani now mostly agrees with the 7714 and Apogee.

What conclusion can I draw? It would appear that the probe still used in the first Barani somehow responds poorly?

From 11:00 to 13:30 the situation is slightly more confusing. But the pattern seems to be that still the new steel probe in the Barani responds way better to changes.

 [ You are not allowed to view attachments ]

My next step is going to be replacing the Apogee probe with the same probe now in the second Barani. My expectation is that adding a more responsive probe combined with the fan will mean even better response times/responsiveness.
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #9 on: August 22, 2021, 11:00:58 AM »
hi, if you want to get an idea of ​​how the various solar screens or stations are doing, I suggest you take a look at this dedicated post,
hi, if you want to get an idea of ​​how various screen stations go, I suggest you take a look at this dedicated post,
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #10 on: August 22, 2021, 01:40:25 PM »
hi, if you want to get an idea of ​​how the various solar screens or stations are doing, I suggest you take a look at this dedicated post,

Did you intend to link a topic?
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #11 on: August 22, 2021, 01:59:06 PM »
hi, if you want to get an idea of ​​how the various solar screens or stations are doing, I suggest you take a look at this dedicated post,

Did you intend to link a topic?

sorry I was wrong discussion, I had not even noticed
you can delete my message
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline ivano

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Re: Explaining differences between shields
« Reply #12 on: August 22, 2021, 02:04:54 PM »
however bad idea to change the plastic probe sensor with the metal one, now I understand why the davis 7714 was so high as values ​​compared to the pro, the netallo one is used more to immerse it in liquids or on the ground, in free air it gets too hot and offsets the temperature values
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #13 on: August 22, 2021, 02:15:19 PM »
however bad idea to change the plastic probe sensor with the metal one, now I understand why the davis 7714 was so high as values ​​compared to the pro, the netallo one is used more to immerse it in liquids or on the ground, in free air it gets too hot and offsets the temperature values

Is that specifically the probe I used, or metal probes in general?
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #14 on: August 22, 2021, 02:22:38 PM »
however bad idea to change the plastic probe sensor with the metal one, now I understand why the davis 7714 was so high as values ​​compared to the pro, the netallo one is used more to immerse it in liquids or on the ground, in free air it gets too hot and offsets the temperature values

Is that specifically the probe I used, or metal probes in general?

they are all metal probes that do not fit in a sun screen that is used to measure the air temperature, you try to insert a plastic probe in the davis and you will immediately see the difference
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #15 on: August 22, 2021, 02:36:38 PM »
they are all metal probes that do not fit in a sun screen that is used to measure the air temperature, you try to insert a plastic probe in the davis and you will immediately see the difference

In the topic you posted above, Ivan13 responded to me arguing (as I understood it) that the metal SHT35 probe should be considered superior to the plastic probe.

https://www.wxforum.net/index.php?topic=40562.msg417550#msg417550

You disagree with him then?
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #16 on: August 22, 2021, 02:46:59 PM »
they are all metal probes that do not fit in a sun screen that is used to measure the air temperature, you try to insert a plastic probe in the davis and you will immediately see the difference

In the topic you posted above, Ivan13 responded to me arguing (as I understood it) that the metal SHT35 probe should be considered superior to the plastic probe.

https://www.wxforum.net/index.php?topic=40562.msg417550#msg417550

You disagree with him then?

absolutely not, I have done these tests in the past, and the result confirmed it, much better the white plastic probe,
« Last Edit: August 22, 2021, 02:49:33 PM by ivano »
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #17 on: August 22, 2021, 02:56:38 PM »
much better the white plastic probe,

Got it. Some confusion here since it seemed like the conclusion drawn was that the metal probe was better.
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline ivano

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Re: Explaining differences between shields
« Reply #18 on: August 22, 2021, 03:00:56 PM »
even the graphs he posted show that the plastic probe is more performing, and with low solar radiation, let alone with high solar radiation and high temperatures, it definitely takes 2 degrees,
 [ You are not allowed to view attachments ]  [ You are not allowed to view attachments ]
1)3 gw1000
2)hp2551
3)ws80
4)ws68
5)2 wh32 EP
6)5 wh31 EP
7)2 meteoschield pro
8)schermo lastem LSI
9) davis 7714
10)wh40
11)schermo solare RAD-14 Metspec
12)schermo solare RAD-02 Metspec
13)Meteorain 200 compact (Barani)
14)davis ventilato h24
15) Davis vp2 pro ventilata
16) GW1001 ecowitt
17) Wittboy ecowitt
template http://ortellemeteo.altervista.org/pwsd/
webcam :https://rtsp.me/embed/tRhazi3z/
http://www.supermeteo.com/stazione/ortelle/

Offline hmderek

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Re: Explaining differences between shields
« Reply #19 on: August 22, 2021, 03:08:11 PM »
even the graphs he posted show that the plastic probe is more performing, and with low solar radiation, let alone with high solar radiation and high temperatures, it definitely takes 2 degrees,

I would have drawn your conclusion too, that the plastic probe is less affected by solar radation.

However Ivan13 argued there:

Quote
In my opinion yes, in equal conditions (inside the sun screen) the right temperature is the highest one, already it is the sun screen that does this work.  If you also look at the humidity graph, you notice that the metal probe sensor detects a higher humidity than the plastic one.

Hence my confusion about what was being concluded based on the readings.

Interesting research too by zoomx in that topic too.

Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline hmderek

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Re: Explaining differences between shields
« Reply #20 on: August 24, 2021, 10:22:11 AM »
A hypothesis could be that the sensor is too big and this reduces the flow rate of the air it can suck in. Maybe you should opt for much smaller probes

For those who are interested, I asked Apogee tech support about this one. Not too many details, but they did say that any probe diameter below 19mm should not cause issues with the flow rate.

Going to keep testing.
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl

Offline hmderek

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Re: Explaining differences between shields
« Reply #21 on: August 25, 2021, 03:45:03 PM »
While the steel probe in the Apogee is prone to some sudden spikes that appear a bit extreme, overall I'm not unhappy comparing it to what I considered my best shield/sensor combination.

Due to a little extra cooling during the night, the Apogee actually ends up 0,02 degrees cooler for the entire day.

Going to be trying a new SHT35 plastic probe, as I had doubts about how I was using the first one.

Also want to try a PT100 pretty soon.

August 24th:
 [ You are not allowed to view attachments ]
Davis VP2
Davis WeatherLink
Sensirion SHT35
PT100
NTC Thermistors
DS18B20
Apogee Instruments TS-100
Barani Meteoshield Pro
Davis 7714
MetSpec RAD14
Davis AirLink
Wemos D1 Mini micro controllers
https://blog.meteodrenthe.nl
https://meteodrenthe.nl