Verification regulation of Equotip hardness tester
This regulation is applicable to the verification of newly manufactured, used and repaired metal Equotip hardness tester (hereinafter referred to as hardness tester).
1 General
The hardness tester, made according to the elastic impact principle, is used to measure the hardness of metal materials. Composed of impact device and display device, a hardness tester has the following characterizes: digital display, small size and light weight. By holding its impact device, the operator can use it to directly carry out hardness test on the materials and workpieces to be tested, and it is especially applicable to hardness test of large workpieces which are difficult to move and large parts and components which are difficult to disassemble.
Equotip hardness test is a dynamic hardness test. The impact device of a hardness tester releases the impact body (tungsten carbide or diamond ball head) from a fixed position, and impacts on the surface of the specimen. The impact velocity and rebound velocity of the ball head at a distance of 1mm from the surface of the specimen are measured. The Richter hardness value is expressed by the ratio of rebound velocity to impact velocity of the ball head. The following equation applies:
(1)
where,
HL——the Richter hardness value, HL;
vA——the impact velocity of ball head, m/s;
vR——the rebound velocity of ball head, m/s.
See Table 1 for the main model and technical parameters of the hardness tester.
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1 General
2 Technical requirements
2.1 Labeling
2.2 Impact device
2.3 Display device
2.4 Printer
2.5 Verification requirements
3 Verification conditions
3.1 Verification environment
3.2 Verification equipment
4 Verification items and methods
4.1 Appearance inspection according to 2.1
4.2 Verification of impact body
4.3 Test result
4.4 Consistency of hardness values
4.5 Verification of indication
4.6 Verification of newly manufactured hardness tester
4.7 Verification of hardness tester in use and after repair
5 Treatment of verification results and verification period
5.1 Treatment of verification results
5.2 Verification period
Annex A Verification of standard Equotip hardness block
Annex B Conversion value of Vickers hardness and Equotip hardness
Annex C Conversion value of Brinell hardness and Equotip hardness (HLG)
