In general, calibration is the process of matching an instrument to a standard scale. More specifically, in the field of metrology, calibration involves comparing the measurement values of an instrument, such as a gage, to those in a set, known as a calibration standard, that have a known degree of accuracy. There are a variety of standards that can be used, such as another instrument, a device with a known size or output, or another measurement object, such as a ruler. The most important quality of whatever comparison you use is that its measurement is known to be completely precise and accurate. This way you are guaranteed to be matching the gage or tool you need to calibrate to be just as precise. Tools and devices should go through calibration or re-calibration on a regular basis. Back to entire glossary
