ISO 6507-2:2018 pdf free

ISO 6507-2:2018 pdf free.Metallic materials – Vickers hardness test
Indirect verification shall be conducted in accordance with the schedule given in Clause 7.
Indirect verification involves verification of the overall performance of the testing machine by means of reference blocks calibrated in accordance with ISO 6507-3.
The testing machine shall be verified by testing reference blocks that have been calibrated in accordance with ISO 6507-3. The blocks shall have been calibrated using the same test forces that the machine will use for future testing. When verifying more than one test force, at least two reference blocks shall be selected from the hardness ranges specified below for each test force that the machine will be verified.The set of blocks needed for verifying the machine for all the test forces shall be chosen so that at least one reference block from each hardness range is used for the verifications. When verifying testing machines using only one test force, three reference blocks shall be used, one from each of the three hardness ranges specified below. The hardness ranges should be chosen, when possible, to replicate the hardness levels most commonly tested when using the specific test forces.
One of the reference indentations from the current calibration period on each reference block shall be measured. For each indentation, the difference between the mean measured value and the certified mean diagonal length shall not exceed greater than 0,001 mm or 1,25 % of the reference indentation length. If preferred, this check may instead be made on a similarly-sized indentation in a different reference block with similar hardness.
On each reference block, five indentations shall be made and measured. The test shall be carried out in accordance with ISO 6507-1. Only the calibrated surfaces of the test blocks are to be used for testing.
Direct verifications shall be performed according to the schedule given in Table 6. It is recommended that direct verifications be performed every 12 months.
Indirect verification shall be performed at least once every 12 months and after a direct verification has been performed.ISO 6507-2 pdf download.