Topic: Field study thermometer shields FARS 7755, Passive 7714, & new METEOSHIELD

[jerryg]

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.

[ValentineWeather]

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?

[ValentineWeather]

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?

PM from Jerry he has custom SHT75 built for the pro shield.
Performance on 75 does look promising also not displaying the high humidity. 

[ValentineWeather]

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

I only posted to help forum members who want to get away from FARS. The safe thing is wait for some test to get done by members and not trust Metoshield testing especially since the SHT is bigger sensor than original probe they used. Airflow may be restricted and shield a failure.
I spent enough time with them being it was my original idea and get the same $25 discount. If the product works great if not don't blame me.

[Bobvelle]

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

And how much are you making off each sale?

    Just Kidding

I wish I could use these but even the greatest passive shield on the planet will have issues in areas with stagnate air, Right?. However... I'm keeping an open mind... and I might bite.

[kcidwx]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

[Bobvelle]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

I looked at that. But I wish they would have recorded (or reported) wind conditions. The gallery photos show a lot of wide open spaces and a couple appear to be next to a large body of water (ocean, sea, gulf?)

[ValentineWeather]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

Well it's their product, I know how those test can go.   
 
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.

[Old Tele man]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

Well it's their product, I know how those test can go.   
 
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 EMPTOR

[ValentineWeather]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

Well it's their product, I know how those test can go.   
 
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 EMPTOR

I agree. Buyer beware is another.
Sensor size started worrying me. What if sensor causes restriction?
I'm actually liking what I see on the 7714 so far and it's less than 1/2 the price if purchased through Ryan at SI.
Nice sunny days toward end of the week forecast 95°. 

[CW2274]

They have already done some tests. Including the VP2 FARS.

https://www.allmeteo.com/radiation-shield-comparisons/

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.
Just sayin'....

[ValentineWeather]

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. 

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[jerryg]

Here's a interesting test comparison of the shield. Scroll down to the pix of stevenson screen and expand the comments. https://www.facebook.com/allmeteo/

[ValentineWeather]

And those are all passive shields. Doesn't say much good about the Vaisala. Big numbers for all being passive just shows how different they can be and why some don't trust passive shields.  Good comparison for the Meteoshield. 

[ValentineWeather]

Jerry would you know if the lite and standard are same shields. Noticed on FB they used the term lite in Aug 2017.

[Old Tele man]

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. 

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Looks to me as though DFARS would likely be adequate, of course, you're not at 100ºF and still winds.

[jgentry]

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

[ValentineWeather]

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.

Think so too. The meteoshield results will be interesting. I don't think it can do any better, how can it? But who knows without testing. One of the knocks on Davis fars it read lower than reference on calm days and higher windy days. Theoretically based on WMO study the reference may have been dead on with the fars reading low being 7714 was within 97-99% of reference in desert testing with 40-45c common temperatures.

[Bobvelle]

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

Maybe I don't know what the hell I'm looking at (very likely  ) but the graphs seem to show the gill plate shield doing pretty well against the others. At least in the inner shield temp vs the sensor temp.

[ValentineWeather]

Oops! forgot the other graphs,

Day-2, was a great test day with light winds and only few clouds later. 7714 was +1.6°F vs FARS at the in town station with less air movement .  Not sure if this is acceptable for all but IMO still not a total bust.  Hoping the Meteoshield does better.

The wind speeds are recorded at 30' not ground level.

The station outside of town wide open, temp max was 85°, 1 degree lower most likely due to better air movement.
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[Bobvelle]

So I'm confused. The 7714 passive shield plates come out of the box, black on the underside ? Or you had to paint them?

[dendrite]

I think I'd give up that 4% RH in exchange for the 1.5F temperature, but that's just me. That's definitely not bad for a passive with almost full sun on it all day though. Temp is always my first priority. Humidity is way down the list...probably a hair above solar/uv. 

[ValentineWeather]

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.

[hwcorder]

For some of you that have extra money lying around and want to go high tech with your black coating. By the way its apparently on sale! 

https://www.acktar.com/product/light-absorbing-sample-kit-standard-adhesive/

[Bobvelle]

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?