รายละเอียดเอกสาร

This Standard specifies a method of verification and calibration of testing machines for determining Knoop hardness in accordance with JIS Z 2251-1. A direct method of verification and calibration is specified for the testing machine, indenter and the diagonal length measuring system. An indirect verification method using reference blocks is specified for the overall checking of the machine. If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method. It should be noted that using the method specified in this Standard for determination from indentations < 20 µm in diagonal length may cause large uncertainties in the results.