Temperature Requirements for an In-House Calibration Laboratory

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fortyfour73

Good day,

Was trying to find where to get information on the temperature and humidity requirements for a Calibration Lab.
I realize there are specifics for what is being tested, but I have a "multi-purpose" lab where I do in house testing for our manufacturing facility.

Need some support to back a situation and move lab in facility to a more controlled area.

Any Help?????
 
S

suffelde

Re: Temperature Requirements for an In-House Calibration Lab

20 degrees C +/-1 and <70% RH should do as a rule of thumb. You are right, some instruments' requirements will be different depending on their application.
 
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Duke Okes

Re: Temperature Requirements for an In-House Calibration Lab

Requirements should be based on the equipment which has the tighter requirements, assuming these don't overlap requirements for other equipment.
 

Jerry Eldred

Forum Moderator
Super Moderator
Re: Temperature Requirements for an In-House Calibration Lab

20 Deg C is a common requirement for a dimensional lab, while 23 Deg C is a common requirement for an electronic lab. What I've had to do is make a chart listing the temperature requirements for my standards and base the lab requirements for them.

If you are using gage blocks, you'll need to consider not only that they are normally certified with values at 20 Deg C (so you may have to apply correction factors if your area is different), but stability will impact settling of devices being calibrated.

In the electronic areas, you'll need to see what the maximum and minimum operating (not storage) temperatures are for each standard, and possibly some numbers for items being calibrated.

For an electronic labs also, 23 Degrees C plus or minus 5 Degrees is a typical least accurate limit, 23 +/- 3 is typical medium accuracy, and an electrical standards lab should typically be 23 +/- 1 Deg C. Dimensional labs that use gage blocks are typically 20 Degrees C +/-1 Deg C.

As for RH, my tightest requirement is 30 to 70 %RH. 45%RH +/- something (depends on your circumstances). One of the typical lower RH limits is 30%RH (as that is considered an ESD threshold).

Those are just a few examples. If it were me, I would make a manufacturer/model list of my most critical lab standards, and look up their temp and RH limits along with coefficients (where applicable), and put them in a table. This is a handy document to have around.

One other recommendation is that if possible, what ever limits are on your standards, set your lab limits a little tighter to preclude problems. As you would need to potentially shut down operations when there is an excursion outside your limits.

And a final thought is to keep a watchful eye when reading specs that some instruments have more than one set of limits. A Fluke 8508A high accuracy digital multi-meter, for example, has separate specs for different lab environments.
 
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Citizen Kane

Re: Temperature Requirements for an In-House Calibration Lab

Hi !

For our lab we have 22-24 celsius degrees temperature. Some infulences we had before were due to the linsk with the humidity ans temperature control of the production area - so, some switches and adjustments were made for isolating the lab. You should get also this possible influences in considerations. Now, our facility guy are :)
 
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WalkingSeed

Re: Temperature Requirements for an In-House Calibration Lab

Good day,

Was trying to find where to get information on the temperature and humidity requirements for a Calibration Lab.
I realize there are specifics for what is being tested, but I have a "multi-purpose" lab where I do in house testing for our manufacturing facility.

Need some support to back a situation and move lab in facility to a more controlled area.

Any Help?????

NCSL Recommended Praactice #7 covers environmental conditions for labs. You may also want to look at the NIST handbook 150 series of publications. These will provide more specific environmental requirements relevant to the task. Also, ISO guides such as ISO-8655 for pipettes will provide temperature requirements. There is no one perfect room for all measurements and typically a calibration lab will be forced to satisfice their environmental conditions in order to manage costs. I have seen one in-house lab that had segregated environments for the different requirements. Over $2,000,000.00 was spent building the facility.

How I approached this issue in one lab:
Most electronics labs are satisfied with a 23C +/- 5 nominal temperature and 50% +/ - 15% humidity. Both of these are too high for dimensional and mass measurements which require 20C nominal and a humidity less than 50% to prevent corrosion but not so low that static becomes an issue. Volumetric devices should be calibrated in a cool (20C) environment the same as dimensional and mass but ideally the humidity should be greater than 50% but not so high as to be detrimental to the electronics on the balances. We have one room to do it all in so what do we do? We control the temperature toward the low side, our temperature control is set to 21C +/- 3C. Humidity is maintained between 35% and 55%. Since evaporation is an issue for volumetric calibrations, volumetric calibrations are done in hoods with small pans of water to control evaporation by contributing moisture to the hood atmosphere. Smaller volumetric calibrations such as pipettes are done on balances with moisture traps to further control evaporation.
 
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Inunez

Re: Temperature Requirements for an In-House Calibration Lab

Here is a question in the same breath as this post. What should a calibration laboratory use as a temperature and humidity reference. chart recorders such as the ct7100 are alright, except for the uncertainties associated with how the ink reacts with the paper. Can anybody suggest another unit?
 
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fortyfour73

Re: Temperature Requirements for an In-House Calibration Lab

there are many digital set ups out there that use wireless to computer. I like these for the ability to set up and print or continuously track and what ever set time intervals you have and ability to move temperature wand to different places and have multiple wands. Omega Engineering and Monarch both have some great choices to go paperless.
 

Hershal

Metrologist-Auditor
Trusted Information Resource
WalkingSeed, great reference to the NCSLI RP7.
Great detail Jerry in your response.

FortyFour73, you mentioned you also do testing. Do you test and calibrate, or only calibrate?

It may help us a bit more if you can give just a bit more detail.
 
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