emissivity offset by humidity
emissivity offset by humidity
(OP)
I am trying to get some accurate reading for air temperature... I am able to get the air temperature by using a probe, but I would like to have the option of using a temp gun...
The humidity is between 90-95% at all times... I have currently tried using white bond paper, but the paper does not stay accurate very long due to the high humidity because it’s absorbing the water... I have also tried using Scotch super 33 on a few different surfaces (foil, paper thin plastic, paper) and I seem to be battling the same issue... The air temps should be about 30.1 Celsius however after about 3-4 hours of being exposed to the humidity the reading will bounce all the way up to 31.5 (or round about)… Before the 3-4 window I am able to get accurate readings… The probes are not showing a bounce…
I am making an 8” square with the tape…
Is there a humidity equation out there somewhere? Any suggestions?
Thanks
Shiloh
The humidity is between 90-95% at all times... I have currently tried using white bond paper, but the paper does not stay accurate very long due to the high humidity because it’s absorbing the water... I have also tried using Scotch super 33 on a few different surfaces (foil, paper thin plastic, paper) and I seem to be battling the same issue... The air temps should be about 30.1 Celsius however after about 3-4 hours of being exposed to the humidity the reading will bounce all the way up to 31.5 (or round about)… Before the 3-4 window I am able to get accurate readings… The probes are not showing a bounce…
I am making an 8” square with the tape…
Is there a humidity equation out there somewhere? Any suggestions?
Thanks
Shiloh





RE: emissivity offset by humidity
I would suggest you are probably within the limits of accuracy and repeatability for the instrument you are using, but you may want to check the specifications.
If I can be of further assistance, please feel free to contact me.
John Snell
Snell Infrared
http://www.snellinfrared.com
RE: emissivity offset by humidity
The reason I am getting a higher reading after 3-4 hours is because the humidity has saturated the paper/tape... I am suprised that with no condensation in the enclosure that the tape is affected... The setup is a Forma incubator with a sterilite tub inside the incubator... The tub inside has approx 2" of water in it and I an trying to take the air temperature a few inches over the water... As far as I can see the temp inside the tub is .2 higher then the temperature in the incubator, but like I said I am hoping to have a method to check temps at any time, especially in the early morning...
thanks
Shiloh
RE: emissivity offset by humidity
Another thing that might be worth trying is to maintain an airflow across the target, such as with a small muffin fan, as this should evaporate the condensation on a continuous basis.
TTFN
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