Topic: Davis Wet Bulb Station pics

[SLOweather]

I made a wet bulb station to go with the black globe sensor to calculate WBGT temperature.

I've had this particular radiation shied around for years, so long that i'm not sure where I got it. Probably Ambient, or maybe Rainman.

Anyway, I never used it because I couldn't figure out how to mount it or anything in it. After closer examination, I noticed that there are 2 flat recesses molded into the inside of the louver plates, about 3/4" wide. Wide enough for a 1x board to slip in, or a 3/4" wide aluminum strip. I started with a length of that perforated metal plumber's tape to bend up a proof of concept. That worked well enough to purchase a piece of 1/16" x 3/4" aluminum bar, which I proceeded to cut and bend. I then bent up a U for a sensor mount and pop-riveted it to the bent-up frame.



Here it is, assembled on the bench. That little fan is a perfect force fit into the frame.



Mounted to a post, with the Davis stainless steel sensor mounted with cable ties. The wick is a cotton tee shirt hem. The probe is too large in diameter to use the classic shoelace.



The water bottle mount is made from a piece of 3" plastic drain pipe and a pipe cap.



I haven't mounted or powered the fan yet.

The temperature sensor is connected to one temperature input of a Leaf Wetness and Soil Moisture station. I can still add up to 2 more sensors, and there is room in the shield for another probe, so I could also do a dry bulb sensor.

[Old Tele man]

What are you using the Wetbulb Temperature data for? It's one of the few weather values SELDOM monitored or broadcast. It's most useful to areas/locals where evaporative cooling is used to cool farm animals (chickens, pigs, cows, etc.) I ended up using an Excel add-in module to "calculate" values for my evap cooling analysis.

[RainmanWeather]

Nice adaptation. That looks like the shield from a Fine Offset WH-1080 which we used to sell, Ambient still has replacement parts for it too http://www.ambientweather.com/amminisrs.html.

APRS World has made a very similar adaptation with mount available here: http://www.aprsworld.com/sensors/solarradiation/ and Amazon: https://www.amazon.com/APRS-World-LLC-APRS6547-Radiation/dp/B00DM9BN0M

[SLOweather]

Wet bulb temp is one component of the Wet Bulb (black) Globe Temperature (WBGT) as discussed here: http://www.wxforum.net/index.php?topic=32489.msg329872#msg329872

I had most of the parts on-hand, so I built one. Actually, this is the second one I built. A while back, I did the same thing to calculate humidity and then took it apart.
http://www.wxforum.net/index.php?topic=4844.msg42825#msg42825

What are you using the Wetbulb Temperature data for? It's one of the few weather values SELDOM monitored or broadcast. It's most useful to areas/locals where evaporative cooling is used to cool farm animals (chickens, pigs, cows, etc.) I ended up using an Excel add-in module to "calculate" values for my evap cooling analysis.

[Bashy]

Great setup, well done on the bracket,i take it you buy the Davis temp sensors in bulk then

[Old Tele man]

Is that the final (working) distance between the water bottle and the fan/louver assembly? That much length in the "wick" might be too long; most use short wick lengths to minimize chance of the wick "drying-out" somewhere between the water source and the sensor.

[Bashy]

There is not a vast difference in length compared to an official UKMO setup\

http://www.metoffice.gov.uk/learning/learn-about-the-weather/weather-phenomena/humidity/measuring