z
Press
key to print out the measured values after measurement.
z
Press
FEED
key to manually feed the paper.
2.4 Leeb Hardness Testing Principle
The basic principle is to use an impact body of certain weight impacts against the testing surface
under certain test force, then measure the impacting velocity and the rebounding velocity of the impact
body respectively when the spherically test tip is located 1mm above the testing surface.
The calculation formula is as follows:
HL=1000×VB/ VA
Where, HL—— Leeb hardness value
VB—— Rebounding velocity of the impact body
VA—— Impacting velocity of the impact body
3 Preparation
3.1 Instrument Preparation and Inspection
Verification of the instrument is by using standard test block. The error and repeatability of
displayed value should be within the regulation of Appendix table 2. The instrument and impact device
must be calibrated using a standard hardness block before use as the first time, or having not been used
for a long time, or having reset the instrument system.
Press key, meanwhile pressing down the key to power on the system. Then the user
calibration screen shows as left below.
Test for 5 points on the standard hardness block.
It would display the average measured value
after measuring 5 times. Press
key to
change to its nominal value.
Press key to confirm the calibration finally. Or
press the
key to cancel the calibration.
Range of adjustment: ±30HL.
The measurement parameters, including the material setting, the hardness scale and the impact
direction can’t be changed during calibration.
3.2 Impact
Device
Selection
Refer
to Appendix
Table 1 and Table 3 for selection of impact device.
Note
：
Use a calibrated hardness tester, test the standard test block
downward vertically for 5 times, the arithmetical average value compare with
the value of standard test block. If this value exceeds the standard value, could
use the function of user calibration to adjust.
