Temperature and Humidity requirements for a Calibration Laboratory

Control stability

Wallace,
Keep in mind that a ±2°C change within a short time period is also not acceptable (neither for the equipment or for you=egonomics).
If you have a supplier make sure to also specify the rate of change.
I might be neccessary also to specify where in the room the requirements should be fulfilled (in order not to have discussions with the supplier later).

To measure with an absolute accuracy better than 3% RH is usually not easy without to high costs.

Good luck,

An interesting read on the subject of humidity:

https://www.veriteq.com/humidity/index.htm

we recently shut down our IR bench because of the humidity being over 50%....... Dimensional, and electronic I understand.... IR?

Lab conditions will depend on the industry you are in. We are automotive and our lab conditions are TEmp: 62~68°F (17~20°C) and RH 45%~55%, with targets of 65°F and 50% RH. These were taken from the training program we received as quality technicians from Indiania Quality Council.

What kind of IR testing?
Humid air does attenuate IR radiation. It does make sense to stop testing at a certain humidity level.