Calibration n. : The process of estimating the caliber a tube, as of a thermometer tube, in order to graduate it to a scale of degrees; also, more generally, the determination of the true value of the spaces in any graduated instrument.

Example:
What is a Calibration mic and would a home theater system work without it?

Taxonomy
calibration, measurement, calibrated, instrument, accuracy, design, metrology, oscilloscopes, interval, ratio, measuring instrument, indications, calibration procedure, calibration certificate, pressure, vacuum, tube, the organization.

Defination from the web:
Calibration is the set of operations that establish, under specified conditions, the relationship between the values of quantities indicated by a ... The term "calibration" probably was first associated with the precise division of linear distance and angles using a dividing engine and the ...