Re: Dial Indicator Calibration Frequency - ASME/ANSI B89.1.10M-1987
You may be doing this already, but I don't see it written above...
Many dial indicators fail catastrophically (ie. an internal part like a spring breaks). If your usage or your gage may be prone to this as mine are, you might consider having a step before usage against knowns.
For me, I keep a known (calibrated) 75um piece right with the gage. When going to use the gage, it is zeroed first, then the 75um known is measured, then off we go.
It takes an extra 3 seconds, but has caught two gages now that had broken internally. Both had ~6mnths left before being due for recalibration.
Since the 'known' has very little risk of changing (dropping it on the floor and stamping on it wouldn't change it), it is on a much longer calibration cycle.
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