ISO 6507-2-2018 pdf free.Metallic materials – Vickershardness test — Verification and calibration of testingmachines.
This document specifies a method of verification and calibration of testing machines and diagonalmeasuring system for determining Vickers hardness in accordance with ISO 6507-1.A direct method of verification and calibration is specified for the testing machine, indenter and thediagonal length measuring system.An indirect verification method using reference blocks is specifiedfor the overall checking of the machine.
lf a testing machine is also to be used for other methods of hardness testing, it shall be verifiedindependently for each method.
This document is also applicable to portable hardness testing machines but not applicable to hardnesstesting machines based on different measurement principles,e.g.ultrasonic impedance method.
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document.For dated references, only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.
Each test force used within the working range of the testing machine shall be measured.Wheneverthe indenter position affects the applied force, this shall be done at not less than three positions of theplunger uniformly spaced throughout its range of movement during testing.
For testing machines whose test force is shown not to be influenced by the position of the plunger, e.g.closed-loop controlled loading system, the test force can be calibrated in one position.
The test force shall be measured by one of the following methods:
– by means of an elastic proving device in accordance with ISO 376, class 1 or better;
– by balancing against a force, accurate to 0,2 %, applied by means of calibrated masses or another
method with the same accuracy.
Evidence should be available to demonstrate that the output of the force-proving device does not varyby more than 0,2 % in the period of 1 s to 30 s following a stepped change in force.Three readings shall be taken for each test force, F, at each position of the plunger. Immediatelybefore each reading is taken, the indenter shall be moved in the same direction as during testing.Allreadings shall be within the maximum permissible percent relative error,AFrel, defined in ‘Table 1.ISO 6507 pdf download.