BS EN ISO 4545-3-2015 pdf download.Metallic materials一Knoop hardness test一 Part 3: Calibration of reference blocks.
8 Marking
8.1 Each reference block shall be marked with the fllowing particulars:
a) arithmetic mean of the hardness values found in the calibration test, for example 249 HK 1, if possible;
b) name or mark of the supplier or manufacturer;
c) serial number;
d) name or mark of the calibrating agency;
2) thickness of the block, or an identifying mark on the test surface (see 3.7);
f) year of calibration, if not indicated in the serial number.
8.2 Any mark put on the side of the block shall be the right way up when the test surface is the upper face.
8.3 Each delivered reference block shall be accompanied with a document giving at least the following information:
a) a reference to this part of ISO 4545;
b) the identity of the block;
c) the date of calibration;
d) the test force used to perform the calibration;
2) the arithmetic mean of the hardness values in the format defined in ISO 4545-1, 4.2, and the value characterizing the non-uniformity of the block;
0) information about the location of each reference indentation together with the length of the long diagonal.
9 Validity
The reference block is only valid for the scale for which it was calibrated.
The calibration validity should be limited to a duration of 5 years. Attention is drawn to the fact that, for AI- and Cu-alloys, the calibration validity could be reduced to 2-3 years.BS EN ISO 4545-3 pdf download.