Temperature and Humidity requirements for a Calibration Laboratory

D

DuaneG

What are the requirements for a calibration lab regarding temperature and humidity. Our room is so cold because they are worried about humidity. I want to give them numbers. Our average is 64 degrees and 28% humidity.
thanks
 
D

D.Scott

Duane - your lab should function under controlled conditions suitable for performing the tests/calibrations on your scope. Check the specs. you are working to and see if there are specific requirements.

Dave
 

CarolX

Trusted Information Resource
Duane, I moved your thread to this board for better response to your question. I suggest you scroll to the bottom of the page for links to similar threads.
 

Hershal

Metrologist-Auditor
Trusted Information Resource
DuaneG,

The Recommended Practices (RPs) available from NCSLI (National Conference of Standards Laboratories - International) provide some guidance on lab environmants. http://www.ncsli.org

Generally the guidelines for dimensional: 20 C +/- 2 C, 30% to 40% RH.
Electrical/electronic: 23 C +/- 3 C, 40% to 50% RH.

Hope this helps.

Hershal
 
J

JerryStem

Our requirements were dictated by the equipment we use. They have specs like 10-100% humidity and 0-100 degrees Celsius. Basically, it didn't matter! (Mostly X-Ray Fluorescence and Beta Backscatter coating thickness instruments).

We set our specs at reasonable levels we could achieve by normal AC and heating, 60-80F and 20-80% RH. We have temp/humidity gauges that can be adjusted/calibrated by traceable standards but since we don't NEED it, we stopped having them certified. We mainly keep them to record the numbers on our certs because customers expect it.

Jerry
 
N

nitram

Hi Jerry,
Keep in mind that the humidity levels recommended is due to:
1. Corrosion risks increase above 55% RH .
2. Electrostatic discard (ESD) risks increase below 35%RH .


I hope that I'm not misinformed ;-).

Martin
 
W

W. de Jong

Weigh the influences

Hi,

If the lab is not a controlled environment then you should examine the influence of the factors on your testresults. Take the factor into account in the uncertainty calculation. If the weight factor is very high you should take out the risk by controlling that factor. e.g. What we did for atmospheric pressure: measurements showed an atm. pressure of 1018 ± 12 hPa in a timespan of a year. The actual influence of the pressure was not a big contribution to the uncertainty of our method of analyses.
Validated it with test results and there was/ is no problem. We don't have to control the atm. pressure. Same with ambient temperature, saved us the cost of an airco.

BR, Wouter
 
G

Giselle

Duane,

for dimensional measurements 20C (68F) is nominal, you need to evaluate what types of measurements you are making, Chrome/Steel (gage blocks) expand and contract at a rate of 6 microinches per inch of material per degree C. If your measurments aren't any better than 0.00001, then you should be fine at that temperature, but it does sound a little chilly.
 
T

TWallace - 2008

Temperature and Humidity requirements for a Plastics testing lab

I need the assistance of the Cove. I am in the process of upgrading our HVAC system for our testing lab. The ASTM temperature and humidity requirements for conditioning and testing are 23°C ±2 and 50%RH ±5%.

The monitoring equipment information that I have been able to find has acceptable accuracy for temperature but the accuracy for RH for the instruments that I have seen up to this point have been in the range of 1.5 to 2.0%. Does anyone have information regarding monitoring equipment with better RH monitoring accuracy?

If I can't find monitoring equipment any more accurate than 2.0% I will have to control humidity to 50%±3.

Any help would be appreciated.
 

Hershal

Metrologist-Auditor
Trusted Information Resource
Depends a lot on your requirements.....

If the HVAC system controls to +/- 5%, then a chart recorder is typically around 2% accracy.....a datalogger is better and will feed a PC with long term monitoring, useful to make sure you stay controlled.

Have the monitoring instrument(s) calibrated by a lab accredited for Temp and RH under ISO/IEC 17025. Make sure they report the measurement uncertainty.

Hope this helps.

Hershal
 
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