Calibration Subjects and Cycle

Calibration Subjects

What is the calibration subject?
It is stipulated in the “Article 40 of the Operation Guidelines for the National Calibration Institution Designation System”, “ In order to improve the traceability between the national measurement standards under the Article 14 of the Framework Act on National Standards and the measurement instruments used in all fields of the national society, a person who owns or uses a measuring instrument should calibrate the measuring instrument on an regular basis, and for this purpose, it can determine the calibration subjects and the application scope as its own regulations.

The reason why calibration should be conducted in the industrial field
It is because tests and measurements should be conducted using measuring instruments that maintain acceptable accuracy. The accuracy can be verified based on the tolerance required by the specification. This accuracy test is accomplished by comparing and calibrating on a regular basis using an upper-tier standard. Therefore, the subjects to be calibrated should be set on the basis of the reliability of whether its performance can be maintained within the tolerances required by the individual equipment to be measured.
However, there may be some cases in which calibration is not necessary in consideration of the performance or structure of the measuring instrument or cases in which national measurement standards have not been established or appropriate calibration methods have not been developed (e.g., surface characteristics, non-destructive testing fields, etc.), so calibration is impossible in realty.

Setting of Calibration Cycle

It is stated in the Article 40-2 of the Operation Guidelines for the National Calibration Institution Designation System that “When a person who owns or uses a measuring instrument wants to set his own calibration cycle, he should set rationally and reasonably in consideration of precision accuracy, stability, purpose of use, environment and frequency of use of the measuring instrument..

However, it is also sated “ If it is impossible to scientifically and reasonably determine his own calibration cycle, the calibration cycle separately notified by the head of the Korean Agency for Technology and Standards Web Site will be applied mutatis mutandis.”

However, the standard calibration cycle specified in the guidelines for setting the calibration subjects and cycle is the calibration cycle set by estimating the period during which the precision accuracy of the measuring instrument can be maintained when used under the most common conditions. It sets 42 sub-categories / 568 items, but recommend that a person who uses or have measuring instruments in each industry to adjust the cycle in consideration of the accuracy, stability, purpose of use, environmental conditions and frequency of use of the measuring instruments.

This means that it is unreasonable to set the calibration cycle uniformly since the working environment in which the measuring instrument is used by each department and the measurement range and tolerance range may differ even in the same workplace, and it is desirable to set the cycle on the basis of the data of the survey on the actual status of use of the measuring instrument and the measured value for each department. Therefore, the most basic matter to consider is securing measurement data accumulated in the past, which is the basis for the adjustment of cycle.