The purpose of instrument calibration is to compare against metrological standards, assess the indication error of measuring devices, and ensure accuracy in measurements, which constitutes a set of operations for traceability of values from the bottom up. The assessment of this indication error should be governed by the organization's calibration procedures, conducted on a scheduled calibration cycle, and proper calibration records and identification tags should be maintained. In addition to assessing the indication error of measuring devices and determining relevant metrological characteristics, calibration results can also be expressed as correction values or calibration factors, providing specific guidance for the operation of the measurement process.
For example, calipers used by a certain mechanical processing organization were found to be 0.2mm larger than the measurement standard after calibration. This data can be used as a correction value, and the calibrated value, which is 0.2mm larger than the standard, should be marked in the calibration identification and records. During the physical measurement process using this measuring instrument (calipers), subtract the correction value of 0.2mm to obtain the actual measured value. As long as the traceability of the measurement value is achieved and the indication error of the measuring instrument is clearly understood, the purpose of calibration is met.
The purpose of calibration is to conduct mandatory assessment of measuring devices. This assessment falls under the category of value unification, being a top-down process of value transmission. Calibration should evaluate whether the measuring instruments meet the specified requirements. These requirements refer to the error range stipulated by the calibration regulation for measuring devices. Through calibration, it is determined if the error range of the measuring device is within the specified range.
