16
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
