BAQ dynaROCK II, Руководство пользователя

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EQUIPMENT DESCRIPTION AND MEASUREMENT PROCESS
3.2 Leeb hardness measurement process
The measurement process employed here exploits the difference between the
impact and rebound speed of a small impact body. This is fired in the impact
device onto the sample surface with an exactly defined energy. The plastic
deformation on generating the impression on the sample surface requires
energy. Therefore the rebound speed of the impact body is lower than the
speed before the impact. Both speeds are measured inductively 1 mm above
the surface.
The hardness number is calculated according to the following formula:
Where:
HL - Leeb hardness
VB – Rebound speed
VA – Impact speed
From the HL values, hardness numbers in the usual hardness scales are
obtained using empirically-determined revaluation tables. These revaluations
are dependent on material.
12
HL
=
1000
∗
VB
VA