GB/T 18449.3-2012 "Metallic materials - Knoop hardness test - Part 3: Calibration of reference blocks" specifies the calibration method for standardized hardness blocks used to calibrate Knoop hardness testing machines. It details the technical requirements for reference blocks (such as uniformity and stability), the calibration procedures (including the direct calibration method using a reference machine or the indirect comparison method via verified reference hardness blocks), and the evaluation of uncertainty in calibration results. Its purpose is to ensure the accuracy, reliability, and traceability of the values of reference hardness blocks, providing a unified benchmark for the indirect verification of Knoop hardness testing machines.
| Status | Active | ||
|---|---|---|---|
| CCS | N71 | ICS | 77.040.10;19.060 |
| Release Date | 2012-12-31 00:00:00 | Implementation Date | 2013-06-01 00:00:00 |