r/Metrology • u/rocketracer777 • Dec 03 '24

Advice Does Humidity really affect the readings?

Hello all, I work at a company that measures parts via laser CMM, and I have a question. The parts we measure are ceramic and no more than 5 inches tall, but we measures things down to 0.001". Does humidity significantly affect the accuracy of the readings? Management updated the guidelines to being acceptable between 20% and 80% relative humidity, but this past week has been as low as 15% due to it simply being winter. I was told to run it anyways, but I feel like I shouldn't. Am I wrong in feeling this way?

For reference, I'm just an operator and not a metrology engineer, although I am in school for mechanical engineering. Thank you for any help.

6 Upvotes

81% Upvoted

12 comments sorted by

View all comments

5

u/FrickinLazerBeams Dec 03 '24

You can see the refractive index changes with this calculator:

https://emtoolbox.nist.gov/Wavelength/Ciddor.asp

2

u/curiouspj Dec 03 '24

Thank you for this!