ISO 4547:1993

Metallic materials — Hardness test — Calibration of standardized blocks to be used for Knoop hardness testing machines

The method specified is applicable only for determining Knoop hardness in accordance with ISO 4545 giving indentations with long diagonals longer than or equal to 20 micrometres. Describes manufacture of the block, standardizing machine, standardizing procedure, number of indentations, uniformity of hardness, marking and test certificate. Annex A describes adjustment of Abbe/Nelson or Kohler illumination systems.