ISO 6507-2:2018 pdf download – Metallic materials — Vickers hardness test — Part 2: Verification and calibration of testing machines.
2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 376, Metallic materials — Calibration of force-proving instruments used for the verification of uniaxial testing machines ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method ISO 6507-3, Metallic materials — Vickers hardness test — Part 3: Calibration of reference blocks 3 Terms and definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia.org/ — ISO Online browsing platform: available at https://www.iso.org/obp 4 General conditions Before a Vickers hardness testing machine is verified, the machine shall be checked to ensure that it is properly set up in accordance with the manufacturer’s instructions. Especially, it should be checked that: a) the plunger holding the indenter is capable of sliding in its guide without any friction or excessive side play; b) the indenter-holder is firmly mounted in the plunger;
c) the test force can be applied and removed without shock, vibration or overshoot and in such a manner that the readings are not influenced; d) the diagonal measuring system: 1) if integral with the machine, the change from removing the test force to measuring mode does not influence the readings; 2) the illumination device of the measuring microscope produces uniform lighting of the whole observed field with enough contrast between the indentation and the surrounding surface to determine the boundary clearly; 3) the centre of the indentation is in the centre of the field of view, if necessary. NOTE The criteria specified in this document for the performance of the testing machine have been developed and refined over a significant period of time. When determining a specific tolerance that the machine needs to meet, the uncertainty associated with the use of measuring equipment and/or reference standards has been incorporated within this tolerance and it would therefore be inappropriate to make any further allowance for this uncertainty by, for example, reducing the tolerance by the measurement uncertainty. This applies to all measurements made when performing a direct or indirect verification of the machine. 5 Direct verification 5.1 General 5.1.1 Direct verification shall be conducted in accordance with the schedule given in Clause 7. 5.1.2 Direct verification involves: a) calibration of the test force; b) verification of the indenter; c) calibration and verification of the diagonal measuring system; d) verification of the testing cycle.