Having some issues getting my temp. sensor to show the correct temp. I just mounted this sensor over 5’ above the ground, under a eve, with no direct sunlight hitting it, but as you can see it’s showing 8-10 degree’s over what it should be (The station is listed as Warren Township on the WU personal stations area at the bottom of this page)
I know the sensor is working correctly after testing it. This is a LaCrosse Technology WS-2315 weather station.
Any idea’s or suggestions would be greatly appreciated
Warm air rises and if something is reflecting heat under your sensor then it will affect the reading. I had the same problem when I installed my system from Davis. I ended up buying a shield for the sensor to eliminate the bogus readings.
You can see a picture of the passive radiation sheild here:
It is plastic fins with space inside for mounting the sensor. It protects your temp or temp/humid sensor from solar radiation and other sources of radiated and reflected heat.
Not knowing the exact dimensions for the Davis sensor, do you think it would take a Lacrosse Technology WS-2315 temp. sensor? I can send the exact dimensions of the LCT temp. sensor if needed.
I couldn’t really see your sensor in the pictures. I measured the bolt pattern on my shield and estimate the hole inside to be about 4" x 4".
Keep in mind the shield was made specific for my sensor. I can’t tell you if your sensor will fit, or how you would attach your sensor to the shield.
The main idea was to point out that heat radiates and to check your setup and see if that is what is causing your temps to be high. For instance, is there a cement patio directly below your sensor? Is that side of the house facing north & away from direct sunlight? Both of these will affect your readings.
I bought the shield for my sensor for 2 reasons. First, my sensor can’t get wet, ever. The manual was very direct about it, get it wet and you will need a replacment, period. Mounting the sensor in the shield protects the sensor from moisture. The 2nd reason is because of radiation heat, I wanted the best readings I could get. I have my sensor mounted on the south side of my house (in direct sunlight during the daytime) and the shield works very well.
I have pointed my (crappy) webcam at my setup for rain and temp sensor. Have a look at how I mounted them together. The rain bucket is over the temp sensor.
The sensor is the small white box directly under the eve. the wire underneath it is going to a temporary spot for the rain gauge on the ground. Tomorrow I’m going to post a outline of my lot and some additional pics. Under the wall the sensor is attached too is only brown mulch.
ah, yes…under the eve…
sounds good…you would think it would be good…but it doesnt work very good…
its a great heat trap…
for lots of reasons…
i.e not much airflow (the eve traps the rising warm air)
the wall of the house reflects radiated heat right onto the sensor too…and that radiated heat is again trapped/focused right there under the eve…
also, the ws2310 sensor housing is not ideal…
the best thing is to make yourself a louvered free standing radiation sheild…
double louvered is best (i.e a stevenson screen)
or the davis instrument shelter works good too (you can remove the outside housing over the ws2310 temperature sensor to reduce its size)
I had a feeling the eve was acting as a heat trap. Is there anywhere I can find info on building a louvered free standing radiation sheild? The Davis enclosure looks cool, but a bit pricey if I could build something comparable.
Also, is there a way to add a radar image to the default web page? Is it ok to link to a TV station’s radar image? I’d like to use this image…and possibly this other one also…
As for adding images to your web page have a look in your wd webfiles directory, files named datahtmX.txt (where X = 1, 2 or 3) you can add your own html to these files.
Hi. I have the same LaCrosse temp/humidity sensor and ran into the same problem you describe. According to the LaCrosse manual one of the recommended places to mount the sensor is just where you did (me too!). I agree that this is poor advice. I built a homemade radiation shield and it helped some but I ended up buying the Davis shield linked above. The sensor does not fit in the Davis shield even without the rain cover. I had to modify one of the solid plates (second one from the bottom) in order to fit the sensor into the shield by cutting a 2 inch by 2 inch hole. The LaCrosse sensor is just too big for the cavity. I just finished placing the newly shielded sensor in my yard so will wait and the accuracy of the temperature readings. I think this will work but not recommended unless you want to modify the Davis product.
Good Luck
