Amongst the pile of tools in my garage is a nice six-inch caliper, which I use for the occasional minor project around the house. And even though I work in one of the finest dimensional calibration laboratories in the country, where we calibrate thousands of calipers every year, my own personal caliper has not been calibrated in over 20 years.

CalPro is a database of complete step-by-step calibration procedures covering more than 60 types of measuring devices-from gage blocks to micrometers and calipers.