Olympus 27MG, Руководство пользователя

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DMTA-10043-01EN, Rev. C, July 2016
Standard Calibration Measurement 39
[2
nd
F] , [CAL VEL] (VEL) may be pressed following velocity calibration (or at any
time in measurement mode) in order to read and record the material velocity for this
particular material. When measuring this material in the future, this velocity may be
entered by means of the arrow keys, without using the block.
Sound velocity in all materials changes with temperature. For maximum accuracy, the
calibration block should be at approximately the same temperature as the samples to
be measured.
5.4.2 When Material Sound Velocity Is Known
When preparing to measure a different material of known sound velocity, the velocity
may be entered directly without doing the CAL VEL procedure discussed above.
To calibrate for a known material velocity
1. In measurement mode press [2
nd
F] , [CAL VEL] (VEL) . The current velocity will
be displayed.
2. This number may then be changed to the desired value using the [

] , [

] , [

] ,
and [

] arrow keys.
3. Press [MEAS] to complete the entry and return to measurement mode. If the gage
is turned off before the [MEAS] key is pressed, the velocity will not be updated to
the new value, but instead will retain the previous value.
5.5 Zero Calibration
To do the zero calibration, a calibration block of the material to be measured must be
used. The block should be approximately as thin as the thinnest section to be
measured. If the surface of the material to be inspected is rough, the surface of the
calibration block may be roughened to simulate the actual surface to be measured.
Rough surfaces generally reduce the accuracy of measurements, but simulating actual
surface conditions on the calibration block can help to improve results. The exact
thickness of the sample must be known.