15
If the discrepancy of the results does not exceed the maximum error of the hardness
tester, it means that these materials can be measured without additional calibration.
If the discrepancy of the results exceeds the maximum error of the hardness tester, it is
necessary to carry out additional adjustments to the hardness tester (additional calibration)
for one or two samples of hardness from the controlled material.
During the operation of the hardness tester, the task of controlling the hardness (or
other properties) of materials with specific physical and mechanical properties may arise. In
this case, it is likely that additional calibration will not completely eliminate the error that
occurs. In this case, it is necessary to make additional adjustments to the hardness tester (enter
an additional scale in the hardness tester) for two or more samples of the hardness of the
controlled material.
Hardness samples for additional calibration and introduction of additional scales must
be made taking into account the requirements of paragraph 1.9 "Requirements for samples
for additional adjustment of the hardness tester".
In cases where the material of the product has a high structural heterogeneity, and
coarse-grained structure, the method implemented in the hardness tester may not allow
ensuring control of these products. Measures to further calibrate and introduce an additional
scale will not give the desired result. There will be a big scatter of readings of the device.
Also, these measures may not work for the control of ultra-high or ultra-low hardness
products.
1.9 Requirements for samples for additional adjustment of the hardness tester
A number of samples are required for additional calibration, 1 or 2 pcs. The
recommended ratio of the maximum value of the hardness of the sample Н
mах
to the minimum
value of the hardness of the sample Н
min
- 2.
The number of samples for creating the additional scale - 2 or more.
In case of deviation from these requirements (not recommended), it is necessary to
provide:
− the surface roughness of the sample - is not worse than defined in the table 1.7.
− the bearing surface of the sample must be flat ground.
To Next Page
Loading...
Need help?
General