[Nhcoll-l] [External] easy way to calibrate temperature humidity sensors

[Robert Waller]

Thanks for posting this helpful information Chris.
It appears in the picture that there is a large volume of liquid solution.
To achieve reliable RH control a slurry with some solid above the level of the solution is required. Otherwise there will be stratification of more dilute solution across the top of the solution leading to a substantially higher than nominal RH level.
Rob

From: Nhcoll-l <nhcoll-l-bounces at mailman.yale.edu> On Behalf Of Tacker, Christopher
Sent: Wednesday, October 13, 2021 9:22 AM
To: Lennart Lennuk <Lennart.Lennuk at loodusmuuseum.ee>; nhcoll-l at mailman.yale.edu
Subject: Re: [Nhcoll-l] [External] easy way to calibrate temperature humidity sensors

The link online to the paper is https://nvlpubs.nist.gov/nistpubs/jres/81A/jresv81An1p89_A1b.pdf
Humidity fixed points of binary saturated aqueous solutions<https://nvlpubs.nist.gov/nistpubs/jres/81A/jresv81An1p89_A1b.pdf>
JOURNAL OF RESEARCH of the National Bureau of Standards- A. Physics and Chemistry Vol. 81 A, No.1 , January-February 1977 Humidity Fixed Points of Binary Saturated Aqueous Solutions
nvlpubs.nist.gov
The paper is also attached.  I've included a picture of the setup I use for controlled humidity experiments. I use a HOBO sensor to monitor the humidity and temperature, inside the lid.

Regards,
Chris Tacker


Chris Tacker  (he, him, his)
Research Curator, Geology |  Ph.D., P.G.,
North Carolina Museum of Natural Sciences |  11 West Jones Street | Raleigh, NC  27601-1029
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Subject: [External] [Nhcoll-l] easy way to calibrate temperature humidity sensors

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Hi!



In our herbaarium we have one quite old and one new temperature humidity sensor.

The data is quite diferent though these sensors are placed in the same spot.



Do you know any good and cheap ways to calibrate those senors?



Best regards!

Lennart Lennuk

Head of collections

Estonian Museum of Natural History

+372 6603404, 56569916


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