Recent Posts

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1
Jerryg,

Iíve been keeping an eye on your station, the RW station at the EOC, and two nearby airport stations. I do know that the RW is installed on the roof with pavement and concrete around the general area. Airport has a similar setup except it isnít on the rooftop. Lol.

Even though your station is sited over grass, Iím beginning to think that it shouldnít cause your station to report DPs that are 4-5į higher than the Airport & RW during the daytime hours. It would be more sensible if it was 1-3į higher at times during transpiration but that should be it I would think. The RW & your station matches up well along with the airport at night when it comes to DP. During the daytime, the RW seems to read the same or 1į higher or lower than the airport where you are reading 2-4į higher consistently. The RW air temps during the dayare very representative of your area, even though itís instalked on top of a roof.

Iím getting the feeling that it doesnít matter if you have the SF2 filter or not, the SHT-31 is going to have a wet bias during the daytime hours.

Here are some currents at 3:18p

Jerryg 94/77

RW station: 93/73

ASOS 91/72

The only other idea I have is to calibrate the humidity on the console. That will work fairly well until the humidities get closer to 100% (late 80s & 90s).

My thinking might be wrong here but it doesnít make sense to me when a RW (for example) humidity sensor would perform better than the Davis.

2
Ok just to put some info out there for those who want some accuracy in their sensor i asked Ryan over at Scaled Inst. about a calibrated sensor and he got word back from Davis they offer an nist traceable with paperwork for 100 dollars plus the price of a sensor. That would be the best way to have a known reference to work with.

If you check Davis' NIST reference publications (https://www.davisinstruments.com/product_documents/weather/spec_sheets/NIST_Traceable_Sensors.pdf), you'll see they only guarantee +/- 3% even after calibration. That's worse then the stated specs between 10 and 90%!

If you need a reference device, you can get the psychrometer that jgentry mentioned (http://www.iisusa.com/mobile/Psychro-Dyne-Battery-Operated-Psychrometer-Fahrenheit-BLACK-ORGANIC/productinfo/22014/) that's accurate to <1% for $175. That's only $25 more than Davis sensor + calibration, and is much more accurate. If you want 2% accuracy, you can get a Kestrel 5000 for $260 from Ryan. Those are pre-calibrated at the factory and have a 5 year warranty, including the calibration, and they measure more than just temp/humidity.

Please don't reward Davis for not standing behind their products. Davis could easily have cut this thread short by stepping up and promising to better protect the sensors in the future (installing the SF2 cap) and offering warranty replacements for anyone experiencing abnormally high humidity readings. They chose not to do that and, instead, put their retailers, like Ryan, in the line of fire.
3
I'm testing three of these evaluation boards right now. RH spec: 1.5%

https://www.idt.com/products/sensor-products/humidity-sensors

I'll run them against my three SHT-31 evaluation boards as well.

Were you able to test those IDT sensors out?  How did they do?
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Blue Iris is pretty nice.   Unfortunately they don't have a mac version out there, yet?   I think there are a lot of missed opportunities for software developers for the mac weather stations.
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I just ordered a nist sensor so i will have a calibrated reference to check my working sensor. Ryan over at Scaled Inst. now has the sensor with calibration pricing on his site.
   Ryan has good things at a reasonable price.   
6
I just ordered a nist sensor so i will have a calibrated reference to check my working sensor. Ryan over at Scaled Inst. now has the sensor with calibration pricing on his site.
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Weather Web Resources / Re: NOAA WEATHER RADIO
« Last post by brandon86 on Today at 03:28:48 PM »
For those wondering, if kzz52 keeps going up and down it's due to the fact I've got family who, they love their youtube video and amazon vid stuff so sometimes the connection gets a little shortfall, but I try to keep it up, hopefully things are sounding good now.  Still looking for more streamers on bhsprn.  Haven't seen any more new entries.
8
Davis isn't going to do anything with its software as they have written in the past.   I am using Weathercat and Weatherdisplay and concerned as you are.   I also have Parallels with Win 10. there I have the Weatherlink for windows and the same with Wd.  I am not sure how that will all work out when Mojave comes aboard.      With a weather console,  I can adjust because I can see it, but with my two Envoys, it is a concern. 

9

If that were the case my strongly aspirated ISS and dirty two year old 31 would not have hit and stayed at both 99% and 1%. I'm sure the filter is there to help protect from dirt/dust, but it's becoming much more evident moisture is the culprit in sensor degradation, not aspiration. As a matter of fact, I'm using the two year old 31 now and it's just as good as the newer one.

I'm having a hard time finding 99% when did this occur?  Last 30 days which includes the humid season monson highest is low 90's.
This was back on 2/16, we were WOXOF (super rare here), I hit 99% starting at 10pm and stayed there til, wait for it.......
10:30am the next morning. Yes, 12 and half hours, the spread between temp and dew stayed at 0.3F the whole time. The service time on the 31 then was 22 months. Two months later I put in the other 31 because I was getting gigged for having too low of a dew when I was at 1%. The TUS ASOS and a RAWS both hit 1% also, just didn't stay there as long as I did. Obviously at that time the 31 was a full two years old.
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  I did.  I suggested a sling psychrometer. Inexpensive and works fine .   

...

Yes, I suggested that early on. 

Where? I only show one other contribution to this thread under your screen name. In it you stated that you'd rather not have to read the proceeding 163 posts and asked the O.P. whether he solved his problem. And he answered you.

Then you return hundreds of posts later and imply that you're too important to be bothered reading a bunch of "opinions" and that, once again, someone should furnish you the information you desire upon request?

Should we just put the report on your desk when we're *finally* done or would you like it emailed?

I am done offering any suggestion.

Indeed, there is no reason for you to be here since your station is always "spot on". I mean the rest of us can't even comprehend that the weather is constantly changing and, therefore, how difficult it is to calibrate our stations properly. Only YOU understand that, Aardvark.
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