Dakota Ultrasonics VX User Manual

Page 18

Dakota Ultrasonics

Calibration to a known thickness

NOTE: This procedure requires a sample piece of the specific

material to be measured, the exact thickness of which is known,

e.g. from having been measured by some other means.

1) Make sure the VX is on.

2) Perform a Probe-Zero (refer to page 12)

3) Apply couplant to the sample piece.

4) Press the transducer against the sample piece, making sure that

the transducer sits flat against the surface of the sample. The

display should show some (probably incorrect) sound velocity

value, and the Stability Indicator should have nearly all its bars on.

5) Having achieved a stable reading, remove the transducer. If the

displayed value changes from the value shown while the

transducer was coupled, repeat step 4.

7) Press the CAL key. The IN /

µs (or M /s) symbol should begin

flashing.

8) Press the CAL key again. The IN (or MM) symbols should begin

flashing and a thickness value is displayed. Use the UP and

DOWN arrow keys to adjust the displayed thickness up or down,

until it matches the thickness of the sample piece.

9) Press the CAL key once more to exit the calibration mode. The VX

will now display sound velocities of materials of the same thickness

as entered.