14
4.2.3 Testing
Press down the release button on the top of the impact device to make a
test. At this point, the test sample, impact device and the operator are all
required to be stable; and the force direction should comply with the axis
of the impact device.
Five measurements should be carried out per measuring position of test
sample. The divergence of data should be not exceeds
±
15HL of mean
value.
Distance between any two indentations, or the distance between any
indentation center and the edge of test sample should be in accordance
with the specification of table 6.
For any special material, a comparative test must be performed to obtain
relevant conversion relation if Leeb hardness value accurately conversing
to other type of hardness value is required. Procedures are as following:
tests are made on the same test sample via Leeb hardness tester which
recalibrated well and relevant hardness meter respectively; for each
hardness value, five points which uniformly distributed around hardness
indentation should be chosen to make tests, and tests for three (at least)
indentations should be made; the mean value of Leeb hardness and the
mean value of relevant hardness will be act as relevant values
respectively to make a comparative hardness curve. Three groups
corresponding data should be included at least in comparative curve.
Table 6
Type of
impact
device
The distance of two
indentations center
The distance between
indentation center and edge of
test piece
No less than
No less than
D
、
DC
3
5
DL
3
5
D+15
3
5
G
4
8
E
3
5
C
2
4
