ISO 6507-2:2018 pdf download

ISO 6507-2:2018 pdf download.Metallic materials Vickers hardness test Part 2: Verification and calibration of testing machines.
ISO 6507-2 specifies a method of verification and calibration of testing machines and diagonal measuring 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 the diagonal length measuring system. An indirect verification method using reference blocks is specified for the overall checking of the machine.
If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method.
ISO 6507-2 is also applicable to portable hardness testing machines but not applicable to hardness testing machines based on different measurement principles, e.g. ultrasonic impedance method.
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 ISO 6507-2. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments applies.
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;
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.
5.1.3 Direct verification should be carried out at a temperature of (23 ± 5) °C. If the verification is made outside this temperature range, this shall be stated in the verification report.
5.1.4 The instruments used for verification and calibration shall be traceable to national standards.
5.2 Calibration of the test force
5.2.1 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 the plunger 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.
5.2.2 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.ISO-6507-2-2018

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