Press key to switch between hardness test and strength test. Only D and DC type
of impact device has the function of strength testing. So hardness testing is the only
selection if the impact device is not D or DC type.
Press
key to print out the measured values after measurement.
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:
! שגיאה
הסימניה אינה מוגדרת
.
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.
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
8
198
