BS EN ISO 4545-3:2015 pdf free

BS EN ISO 4545-3:2015 pdf free.Metallic materials一Knoop hardness test一Calibration of reference blocks
The following referenced documents are indispensable for the application 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一proving instruments used for the verification of uniaxial testing machines
ISO 4287, Geometrical Product Specifications (GPS)一Surface texture: Profile method一Terms, definitions and surface texture parameters
ISO 4545-1, Metallic materials一Knoop hardness test一Part 1: Test method
ISO 4545-2, Metallic materials 一Knoop hardness test 一Part 2: Verification and calibration of testing machines
The block shall be specially manufactured for use as a hardness-reference block.
NOTE Attention is drawn to the need to use a manufacturing process which will give the necessary homogeneity,sability of structure and uniformity of surface hardness.
The reference block thickness shall be greater than twenty times the depth of indentation made with the certified test force.
The reference blocks shall be free of magnetism. It is recommended that the manufacturer ensure that the blocks, if made of steel, have been demagnetized at the end of the manufacturing process (before calibration).
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.
The instruments used for verification and calibration shall be traceable to national standards.
Each test force shall be verified at 3 different positions of the plunger, spaced at approximately equal increments covering the limits of travel used during testing. At each position, the force shall be measured three times using an elastic proving device according to ISO 376 Class 0,5 or better, or by another method having the same or better accuracy. Each measurement shall agree with the nominal value to within±0,5 %.
The indenter shall comply with ISO 4545-2 clause 4.3 and meet the following requirements:
a) The angle β (see ISO 4545-1, Figure 1), between opposite edges at the vertex of the diamond pyramid,shall be (130±0,1)°.
b) The angle between the axis of the diamond pyramid and the axis of the indenter holder (normal to the seating surface) shall not exceed 0,3°. The four faces shall meet at a point; the length of any common junction between opposite faces being less than 0,000 3 mm.
The diagonal measuring system shall be verified at a minimum of five evenly spaced intervals over each working range against an accurately ruled stage micrometer. The accuracy of the line intervals on the stage micrometer shall be 0,000 1 mm or 0,05%,whichever is greater.BS EN ISO 4545-3 pdf free.