After I wrote the last column on this subject a number of queries popped up so I figured a sequel would be worthwhile.
A few customers are requesting that reports show the actual lab humidity during calibration of their equipment. I realize that this can be a critical consideration for some types of calibration but when it comes to fixed limit gages, I have never heard the rationale for such a request other than it’s what their customer expects. Most dimensional labs I know of keep humidity between 40% and 50%. It’s true that in days gone by humidity was more critical due to the electronics used at the time. This concern fell by the wayside with the development of solid state electronics. However, if lasers are being used humidity can have a detrimental effect but most of these devices incorporate sensors and electronics to automatically condition their readings to compensate if needed.