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JJG 150-2005: Verification Regulation of Metallic Brinell Hardness Testers
JJG 150-2005
NATIONAL METROLOGICAL VERIFICATION
REGULATION OF THE PEOPLE’S REPUBLIC OF CHINA
Metallic Brinell Hardness Testers
ISSUED ON: MARCH 03, 2005
IMPLEMENTED ON: SEPTEMBER 03, 2005
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China
Table of Contents
1 Scope ... 5
2 References ... 5
3 General ... 5
4 Measurement performance requirements ... 6
4.1 Perpendicularity and coaxiality of hardness tester’s spindle ... 6
4.2 Test force for hardness testers ... 6
4.3 Indenter ... 6
4.4 Indentation measuring device ... 6
4.5 Indicating value’s maximum allowable error and indicating value repeatability
... 8
5 General technical requirements ... 8
5.1 Appearance, installation and requirements ... 8
5.2 Test force application speed and test cycle time ... 8
6 Control of measuring instruments ... 9
6.1 Verification conditions ... 9
6.2 Verification items and verification methods ... 9
6.3 Processing of verification results ... 14
6.4 Verification cycle ... 14
Annex A Record format of verification of test force and indicating value of
Brinell hardness testers ... 15
Annex B Inner page format of verification certificate and verification result
notice of Brinell hardness testers ... 17
Verification Regulation of Metallic Brinell Hardness
Testers
1 Scope
This Regulation applies to the initial verification, subsequent verification and in-
use inspection of fixed metallic Brinell hardness testers (hereinafter referred to
as hardness testers).
2 References
ISO 6506-1 Metallic materials - Brinell hardness test - Part 1 Test method
GB/T 231.1-2002 Metallic materials - Brinell hardness test - Part 1: Test
method
GB/T 231.2-2002 Metallic Brinell hardness test - Part 2: Verification and
calibration of hardness testers
GB/T 231.3-2002 Metallic Brinell hardness test - Part 3: Calibration of
hardness reference blocks
JJG 144-1992 Verification Regulation of Standard Dynamometer
When using this Regulation, care shall be taken to use the currently valid
version of the above-cited references.
3 General
A Brinell hardness tester is mainly used for the determination of hardness of
cast iron, steel, non-ferrous metals and soft alloys. In addition, it can also be
used for the determination of hardness of certain non-metal materials such as
plastic and bakelite.
Use a cemented carbide ball of a certain diameter to press into the surface of
the specimen under the specified test force. After a certain retention time of the
test force, remove the test force. Measure the diameter of the indentation left
on the surface of the specimen. The Brinell hardness value is expressed as the
average pressure on the indentation’s surface area.
The test cycle time refers to the test force holding time and the test force
application time. The maximum allowable error of the test force cycle time is
±0.5 s.
6 Control of measuring instruments
Control of measuring instruments includes: initial verification, subsequent
verification and in-use inspection.
6.1 Verification conditions
6.1.1 Environmental conditions
Hardness testers shall be verified under the environmental conditions of (23 ±
5) °C. During subsequent verification or in-use verification of hardness testers
outside this temperature, the ambient temperature shall not be lower than 10 °C
and higher than 35 °C. The temperature at the time of verification shall be
indicated in the verification record and verification certificate.
6.1.2 During the verification, the surrounding environment shall be clean and
free from vibration and corrosive gases.
6.1.3 Instruments for verification
See Table 4 for instruments for verification.
6.2 Verification items and verification methods
See Table 5 for verification items.
Subsequent verification of hardness testers shall be carried out in accordance
with the methods in 6.2.1 and 6.2.8 for the control of measuring instruments. If
the verification of indicating value is not qualified, it shall be verified and
adjusted according to the methods of 6.2.2, 6.2.3, 6.2.4, 6.2.5, 6.2.6, and 6.2.7
for the control of measuring instruments.
Table 4 -- Instruments for verification
No. Verification item Instruments for verification Name Technical requirements
1 Levelness of test bench of hardness testers Level Division value: 0.2/1000
Perpendicularity of
hardness tester’s spindle
and test bench surface
Calibration rod Cylindricity is not greater than 0.01 mm, effective length is 100 mm
Knife edge square Grade 1: 100 m × 60 m
Feeler (0.02 ~ 1) mm
3 Coaxiality of lifting Measuring Division value: 0.01 mm, Grade II
force of the hardness tester, then adjust the zero position and start the test.
6.2.4.2 The direction of movement of the test force during verification shall be
the same as the direction of movement of the test force during the test, and the
test shall be performed at three positions within the entire travel range of the
test force. Measure 3 times at each position.
The test force error is calculated according to (1):
where: W - the test force error;
K0 - the indicating value of the standard dynamometer corresponding
to the test force;
K - the reading differs most from K0, among the 3 readings.
The verification W result of test force shall meet the requirements of 4.2.2.
6.2.5 Verification of indenter
6.2.5.1 Appearance inspection of ball indenter
Observe the surface state of the ball under a stereo microscope with a
magnification of 100 times. The surface of the ball shall be free of defects such
as pits, scratches, cracks, and rust. Use an interference microscope to measure
its surface roughness. It shall meet the requirements of 4.3.
6.2.5.2 Test of ball diameter
The diameter of the ball shall be measured by a vertical optical length
measuring instrument. The diameter shall be measured in at least three
directions. The measured value of three measurements shall meet the
requirements of 4.3.
6.2.5.3 Test of ball hardness
Samples shall be taken randomly from ball indenters produced in the same
batch and tested with a Vickers hardness tester (HV10). The hardness value
shall meet the requirements of 4.3. The ball indenter after test shall be
discarded.
6.2.6 Verification of indentation measuring device
Check whether the scale of the indentation measuring device is clear and
uniform.
where: Hcf - the indicating value repeatability of the hardness tester;
Hmax - the maximum value of hardness at 5 points;
Hmin - the minimum value of hardness at 5 points;
- the arithmetic mean value of hardness at 5 points.
6.2.8.3 Indicating value error of hardness testers
The indicating value error of hardness testers is calculated according to formula
(4):
where: δ - the indicating value error of the hardness tester;
- the indicated value of the hardness tester (average value of
hardness at 5 points);
- the hardness value of the hardness block.
The indicating value repeatability and indicating value error of hardness testers
shall meet the requirements of 4.5.
6.3 Processing of verification results
The hardness tester that is qualified in the verification according to the
requirements of this Regulation is issued a verification certificate. The hardness
tester that is unqualified in the verification is issued a verification result notice.
6.4 Verification cycle
The verification cyc...