E
Eloy Gomez
What type of gauge blocks would be recommended for calibration of simple measuring precision tools such as calipers, micrometers, height gages, etc....? I was thinking an 81 piece grade B gauge block set?
Here are some things for your consideration:What type of gauge blocks would be recommended for calibration of simple measuring precision tools such as calipers, micrometers, height gages, etc....? I was thinking an 81 piece grade B gauge block set?
I am not sure if ISO 17025 SPECIFIES or SUGGESTS any calibration frequencies but I do recall something along the lines that calibration services labs cannot require or impose specific calibration frequencies on their clients. The decision to increase or decrease verification/calibration frequencies should be based on previous verification results and experience. Therefore the suggestions to place the sets on no more than 3 years or 12 months cycles are just that: SUGGESSTIONS.
I am not sure what the 'white cloth' is but it is known that skin secretion from our fingers can have a corrosive/eroding effect on the bare steel of gage blocks.
Hershal is correct about the uncertainty but fails to explain how it applies to the equipment. I am not sure about the uncertainty being required in order to provide traceability of general inspection equipment to a national or international standard (i.e. NIST) but I am sure that the word 'uncertainty' does not appear or is implied anywhere in clause 7.6 if the ISO 9001 standard. However it needs to be considered because, as a rule of thumb, you don't want the uncertainty to exceed 10% of the equipment's accuracy (i.e. +/-.0001" for calipers accurate to +/-.001"). I have no idea where the 10% came from but I venture to guess that it is based on some statistical data.
Maybe someone else can provide additional information along these lines.
One often finds a measurement instrument which needs adjustment but is not technically out of calibration. The important part is to watch the trend over calibration cycles. If the instrument has to be adjusted more each cycle, even if it is within calibration limits for the instrument, it is probably indicating wear.<snip> ... any adjustments determined to be needed during the calibration process indicated that the instrument was out of calibration. Did I get that wrong? <snip>