DMQ QH5 U, Руководство пользователя

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VI
This manual provides all of the information needed to configure and
operate the QH5 U portable hardness tester. However there are
additional factors that can affect tests done with this instrument.
Specific information on those factors is outside the scope of this
manual. When in doubt you should always seek expert advice or refer
to specific textbooks on portable hardness testing. Additional
information can also be found on the internet and through local
government agencies as well as in technical institutes.
The QH5 U operates on the UCI or Ultrasonic Contact Impedance
method of hardness testing where just like in conventional methods
such as Vickers, Brinell or Knoop, hardness values are obtained by
applying constant force to an indenter which generates an
indentation on the part being tested. But where as in conventional
methods further optical evaluation is required, with the QH5 U
readings are processed electronically and instant measurements are
obtained in the most common hardness units.
Figure 1: UCI probe
Figure 1 represents a UCI probe where the indentor
P
is normally a
Vickers type synthetic diamond cemented to an oscilating rod V which
is excited by a transmitting element T at a frequency that changes
according to the depth of the indentation generated on part
m
.
Frequency changes are detected by a receiver R and finally