Dakota Ultrasonics MX-5 DL - Manual (Page 20)

Dakota Ultrasonics
16
Calibration to a known velocity
NOTE: This procedure requires that the operator know the sound-
velocity of the material to be measured. A table of common
materials and their sound-velocities can be found in Appendix C.
1) Make sure the M X-5 DL is on.
2) Press the CAL key to enter calibration mode. If the IN (or MM)
symbol is flashing, press the CAL key again, so that the IN/
µs (or
M/s) symbols are flashing.
3) Use the UP and DOWN arrow keys to adjust the displayed velocity
up or down, until it matches the sound-velocity of the material to be
measured.
4) Press the CAL key once more to exit the calibration mode. The
MX-5 DL is now ready to perform measurements.
NOTE: At any time during the calibration procedure (IN, MM, IN/
µs, or
M/s flashing in the display), pressing the PRB-0 key will restore the tool to
the factory default sound-velocity for steel (0.233 IN/
µ
s).
To achieve the most accurate measurements possible, it is generally
advisable to always calibrate the MX-5 DL to a sample piece of known
thickness. Material composition (and thus, its sound-velocity) sometimes
varies from lot to lot and from manufacturer to manufacturer. Calibration to
a sample of known thickness will ensure that the tool is set as closely as
possible to the sound velocity of the material to be measured.