2016DIN EN ISO 16859-2:2016 Metallic materials - Leeb hardness test - Part 2: Verification and calibration of the testing devices (ISO 16859-2:2015); German version EN ISO 16859-2:2015
2007DIN 50156-2:2007 Metallic materials - Leeb hardness test - Part 2: Verification and calibration of the testing devices