Topic: Airlink Humidity more Accurate than ISS SHT

[fkapp]

Was looking at Weatherlink data for today and noticed something didnt realize before.
My Airlink which is mounted outdoors Humidity is avg 3 to 5% lower than the Humidity in my ISS which has DFARS and is in nearby part of my backyard.

Quick comparison to the Buffalo Airpot ASOS shows the airlink is closer to the reading there than ISS (which is almost 2 years old)

I have attached a chart I created to show the variances for 10-17 by hour. (11pm obs was not in when i created).

Not sure what SHT sensor they use in the airlink, but appears to be more accurate.
Just sharing my observation and curious if others see similar difference.
Let me know, and maybe I shift to using the Airlink humidity as the actual one for my station.

Thanks
Frank

[CW7491]

Since humidity is relative to temperature, it might be more helpful to compare dew point among the three. If the Airlink dew point is lower than your ISS and closer to the ASOS, you’re on to something.

[ocala]

How far away is the Buffalo airport from your Location?

[fkapp]

Thanks. Added chart of dewpoint comparison for the same times.

Most obs no difference between ISS and Air Link.  A few obs in afternoon 3pm to 5pm Airlink is lower and closer to ASOS, but not consistent.

Guess inconclusive.

[fkapp]

Hi,
Am about 3 miles north of Buffalo NWS

Thanks
Frank

[Maximus]

The AirLink's design places the T/H sensor near the intake of the fan used to pull particles into the counter. In this way, it acts like a miniature SPARS unit, since fresh air is constantly pulled across the sensor. As long as the AirLink itself is shaded from the sun at all times, it will give proper outside temp and humidity readings.

[Bashy]

Straying a little off topic, can the Davis air sensors become clogged? I ask because i am thinking about getting one, perhaps next year now but i have a unique homemade shield for my old OS temp/hum sensor, this has a fan at the bottom and i used an old OS rain gauge debris screen (its a fine mesh) to slip over the fan just to protect it some. I have to clean off that screen at least twice a year, is there a filter of sorts in place for the davis air quality sensor? I am thinking not as this would defeat its purpose?

[mcrossley]

It does have a filter screen, but it is not in place out of the box. If you want to fit it you have to open the case and retrieve it from its storage position and move it to the slot behind the openings.

[Bashy]

It does have a filter screen, but it is not in place out of the box. If you want to fit it you have to open the case and retrieve it from its storage position and move it to the slot behind the openings.

Thank you, that's good to know

[drew1021]

Was looking at Weatherlink data for today and noticed something didnt realize before.
My Airlink which is mounted outdoors Humidity is avg 3 to 5% lower than the Humidity in my ISS which has DFARS and is in nearby part of my backyard.

Quick comparison to the Buffalo Airpot ASOS shows the airlink is closer to the reading there than ISS (which is almost 2 years old)

I have attached a chart I created to show the variances for 10-17 by hour. (11pm obs was not in when i created).



Not sure what SHT sensor they use in the airlink, but appears to be more accurate.
Just sharing my observation and curious if others see similar difference.
Let me know, and maybe I shift to using the Airlink humidity as the actual one for my station.

Thanks
Frank

First mistake is comparing your readings to ASOS. You don’t know for sure if it is accurate. Second is natural landscape, more than likely more trees where you live. If you’re going to compare then use dew point as someone else mentioned.

[fkapp]

Sharing interesting observation 11pm this evening.
Rained all day with drizzle/fog at the moment.

Airlink Humidity hit 100% past hour vs 97% for VP2 shield.  (no 24 x7 FARS yet)
Dewpoint 47 for both. 

Buffalo NWS 3 miles away is also 100% Dew Point 47 at 11pm.

Interesting to see airlink hit 100% humidity as this is first since got this outside this summer.

Just wanted to pass along as was unexpected but definitely soggy evening.
Frank

[Bashy]

I am 98% sure that i have never seen my vp2 humidity above 98% (raw) since i have had it, DOB 2017