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Well before we 'throw out the baby with the bath water'. Let me clarify some things.

1. The location of the FARS shield IS partially covered by the 30w PV panel above it during the noon hours and the Meteoshield is fully exposed.

2. I'm not sure if it matters..(and it shouldn't ) but I realized this morning that the SHT31 in the Meteoshield is mounted with the sensor facing south, fully exposed to the southern facing gills. It is perfectly centered horizontally and vertically in the shield cavity. Mounted with 3/4" standoffs to a small piece of black Kydex I molded into a bracket.

I will, this afternoon, attempt to move the FARS 180 degrees opposing (on a east/west axis) the Meteo shield. This way insuring they get simultaneous and equal sun exposure. I will also turn the sensor to face a neutral position like Northeast, but other than due south. (this was purely coincidental   #-o).

After which, I will post another day's results. Honestly, I'm not expecting MUCH improvement, but at least it will be a more honest comparison.
WeatherUnderground / Re: WU - Let us know your issues
« Last post by miraculon on Today at 10:16:28 AM »
My monthly summary data is showing a low temperature of "0" degrees F on random days the past few weeks (see screenshot below).  I have a Davis Vantage Vue and upload to WU using the Weatherlink software via USB.  A check of my data does not show any "O" degree readings.  Anyone else experiencing this or have an explanation?  Thanks for any help or insight.


It appears to be more than just temperature. On August 14, 2018, at 9:40 AM, all of your data drops to zero. Are you also uploading anywhere else, like CWOP that you can compare? If your local data was OK at this time, then something happened with the upload apparently.

You screen capture shows max/min, but your station on WU shows current temp. I had to go back a few days to find the dropout. It is also present in the table view:

August 14, 2018:   9:40 AM    0 F    -- F    0 %    North    0 mph    0 mph    0 in    0 in    0 in

Greg H.
I've decided to stop testing on standard shield.
I see no reason to continue, it reminds me of the Davis Pro shield. Once any shield gets in the +2 range and looking at Bobville graph confirms not interested.

I've asked for a return RMA#.
Still interested in pro shield so not completely done testing.
Method 3: WS-2902A - How to Send Weather Data to CWOP

As if that was not enough there is actually sort of a 3rd method which is like a hybrid of both prior methods to get the WS-2902A to publish to CWOP.

This 3rd method requires the ObserverIP and the WS-1000-BTH but instead of the Meteobridge (Weatherbridge) you do the whole network redirection mentioned in method 2 above.  And so instead of capturing Weather Underground traffic from the WS-2902A display console you are capturing it from the ObserverIP over to the WeeWx computer. But there is more...don't stop reading yet.

This 3rd method actually has an advantage that may reduce some of the complexity of method 2. Since the ObserverIP can be modified to run an older version of its firmware you can then do the Weather Underground network redirection with just the ObserverIP. No need for router with complex custom firmware and no need for network expertise. This is because there is an older ObserverIP firmware that lets you change the IP address for the Weather Underground server. So instead of the ObserverIP sending data directly to Weather Underground you configure it with the IP address of your WeeWx computer and bingo, you have the data in WeeWx without needing to do the complex network redirection and without all that extra hardware. There are many old firmwares available to download for the ObserverIP. I don't know off hand exactly which older version is a good one that lets you modify the Weather Underground server IP address. This feature on the ObserverIP was blocked (removed) from the current firmware versions.

Note: In case you were wondering...The WS-2902A does not have the capability of changing the the Weather Underground server IP address.
WeatherUnderground / Re: WU - Let us know your issues
« Last post by Northwoodsman on Today at 09:25:00 AM »
My monthly summary data is showing a low temperature of "0" degrees F on random days the past few weeks (see screenshot below).  I have a Davis Vantage Vue and upload to WU using the Weatherlink software via USB.  A check of my data does not show any "O" degree readings.  Anyone else experiencing this or have an explanation?  Thanks for any help or insight.

Naturally aspirated to boot, with a caveat. "A further benefit of the MetSpec shield design is that the measured temperature is now even closer to reference temperature measurements made using artificially aspirated motors without the drawbacks of such systems
(power and the maintenance of moving parts)"

No fan? Until passive shields measure up completely to aspirated, it's a waste of the best sensors in the world.
I'll stick to my fan needing replacement every 7 years.

Let me simply begin with saying that I agree with you on the fact that radiation shields without aspiration will not be as accurate as shields with aspiration. However, I'd also like to point out that multiple case studies have been done and are easily retrievable. I believe you might be surprised with the results, but passively aspirated Gill/R.M. Young shields performed with little to no error with artificially aspirated ASOS shields.

There are many consumer grade radiation shields that hit the mark quite well with keeping temperature accurate during the day, as long as they are placed properly. In my case, I own an Ambient Weather WS-1001-WiFi. Call me cheap, but the radiation shielding on it has been excellent. 80-85 degree relatively calm days so far have yielded readings at or lower than official stations, and from that I can only conclude that the radiation shield from Gill on a $4500 station is quite well engineered.

No measurement will ever be perfect, and fan aspirated shields may perform better than passively aspirated. However, I believe that the difference is very minimal in this situation, and as a contributing factor, the wind is almost always blowing through the sensor as well.

Carbon, you are quite right ... furthermore, any noticeable difference between a brand new (calibrated) fan aspirated thermo-hygrometer and a naturally aspirated, will be lost after 2 or 3 months due to contamination.

I'll stick to my fan needing replacement every 7 years.

CW2274 > You replace the fan every 7 years... in that same period, how often do you replace/calibrate your thermo-hygrometer?
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:
This is my Davis FARS vs Meteoshield standard temp graph for yesterday. They are mounted about a foot apart and both housing a SHT31 sensor w/sensirion filter. Not real impressed, although I'm not surprised as I get very little wind here.

FARS= Blue
Meteo= Orange

afternoon wind ~ 1.5 mph

 [ You are not allowed to view attachments ]
I looked at data logger from yesterday and these were the recorded highs. So .7 between the 7714 and Pro.
Made correction.

PRO-        79.6
Standard- 80.6
7714-       78.9
FARS-       78.5

Lows today

Pro-          55.6
Standard- 55.5
7714-       56.1
FARS-      55.7
Method 2: WS-2902A - How to Send Weather Data to CWOP

There is actually another method for the WS-2902A to publish to CWOP but it is more complicated. But it is potentially cheaper than getting the ObserverIP, WS-1000-BTH and Meteobridge (WeatherBridge). It really depends on what computer and network equipment you may already have.

This other method to publish to CWOP mostly requires the use of a computer (an old one you already have lying around, or a cheap one, or it is popular to use a Raspberry Pi because they are cheap, small and take up little space.) Then add some software. You'll also need an old router that can run custom firmware or get a cheap router capable of running WRT or Tomato.

The software you need for the computer is WeeWx. You'll need to use the WeeWx interceptor driver to capture data being sent by the WS-2902A display console via the custom router as it sends to Weather Underground. Once WeeWx has this data it can then publish to a number of services including CWOP. And WeeWx will then also pass along the intercepted data to Weather Underground.

In concept the above paragraph explains how it works without getting too technical. But in reality to accomplish all of that it is complex. Because it requires a whole lot more technical experience. You'll need Linux experience, router configuration experience, and networking experience to redirect Weather Underground traffic to the WeeWx computer. Keep in mind that this custom router does not replace your existing router. It sits between your display console and the WeeWx computer from a network design perspective. But there are a lot of guides and write ups. But you probably won't find all the information in one place. And if you are a real network guru and you already have a managed layer 3 switch on your network then you won't need the router with custom firmware as you'll program your layer 3 switch to do the redirection to the WeeWx computer, but your network will have to also have a wireless access point that is not the router if you are using the WS-2902A display console.

It is much easier and convenient to use the first method in my prior post, although probably more expensive.

Note: I don't have any proof but conceptually this method of capturing Weather Underground data via network redirection could potentially be a solution to get any weather station from any manufacture that publishes to Weather Underground to be able to also send data to CWOP. With one caveat...Stations like Netatmo that don't directly publish to Weather Underground via your network have no WU data to intercept. These station publish to only to their private Internet cloud service and then from there it goes to Weather Underground, so it isn't done over your network.
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