Dakota Ultrasonics PR-8V - Manual (Page 10)

Dakota Ultrasonics
6
Known Thickness
Sometimes the sound velocity of a material is unknown. In this case a sample with a
known thickness can be used to determine the sound velocity. It would be very
handy to carry a set of mechanical calipers to use in conjunction with the PR-8V for
calibration in the field:
Using a Known Thickness
Note: Be sure that the probe zero procedure has been performed prior to
performing this calibration procedure.
1) Physically measure an exact sample of the material or a location directly on
the material to be measured using a set of calipers or a digital micrometer.
2) Apply a drop of couplant on the transducer and place the transducer in
steady contact with the sample or actual test material. Be sure that the
reading is stable and the repeatability indicator, in the top left corner of the
display, is fully lit and stable. Press the MENU key once to activate the
menu items tab. Press the MENU key multiple times to tab right and the
ESC key multiple times to tab left until the CAL menu is highlighted and
displaying the submenu items.