The question about calibrating physical/dimensional items in an environment where they are used has come up often over the years. I didn't have time to read all the posts, so I hope I'm not repeating. But it pretty well doesn't work.
Calibrating a micrometer, height gage, digital indicator, etc., the big temperature issue is the coefficient on the gage block, which is pretty well always calibrated at 68 degrees (20 C). If you calibrate a high accuracy out in a shop where the temp could be anything/whatever - you then have to calculate all the variables on tjhe gage block. The expansions on the digital indicator are small in comparison. So it is a dangerous tradeoff that could very well yield incorrect results. My vote is always calibrate items in a proper lab environment. It is the users job to know their instruments and apply corrections as needed, not the calibration lab.
Regarding environmental requirements for an electrical lab, I made a list of all my measurement standards, and looked up each and every temp, RH and temp coefficient (where significant/applicable). And set my lab parameters to be at least better than those. Many electrical standards is +/-5C, with some being +/-1C (precision standards). Our Fluke 8508A's have both. I have a set of HP 16380A capacitance standards that are spec'd to operate from 30% to 70%RH. I have them labeled to assure they are used within acceptable limits.
Calibrating a micrometer, height gage, digital indicator, etc., the big temperature issue is the coefficient on the gage block, which is pretty well always calibrated at 68 degrees (20 C). If you calibrate a high accuracy out in a shop where the temp could be anything/whatever - you then have to calculate all the variables on tjhe gage block. The expansions on the digital indicator are small in comparison. So it is a dangerous tradeoff that could very well yield incorrect results. My vote is always calibrate items in a proper lab environment. It is the users job to know their instruments and apply corrections as needed, not the calibration lab.
Regarding environmental requirements for an electrical lab, I made a list of all my measurement standards, and looked up each and every temp, RH and temp coefficient (where significant/applicable). And set my lab parameters to be at least better than those. Many electrical standards is +/-5C, with some being +/-1C (precision standards). Our Fluke 8508A's have both. I have a set of HP 16380A capacitance standards that are spec'd to operate from 30% to 70%RH. I have them labeled to assure they are used within acceptable limits.
