Checkline MX-3 - Manual (Page 20)

Dakota Ultrasonics
16
Two Point Calibration
NOTE: This procedure requires that the operator has two known
thickness points on the test piece that are representative of the
range to be measured.
1) Make sure the M X-3 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, at the first/second
calibration point, making sure that the transducer sits flat against
the surface of the sample. The display should show some
(probably incorrect) thickness value, and the Stability Indicator
should have nearly all its bars on.
5) Having achieved a stable reading, remove the transducer. If the
displayed thickness changes from the value shown while the
transducer was coupled, repeat step 4.
6) Press the CAL key. The IN (or MM) symbol should begin flashing.
7) Use the UP and DOWN arrow keys to adjust the displayed
thickness up or down, until it matches the thickness of the sample
piece.
8) Press the Probe key. The display will flash 1OF2. Repeat steps 3
through 8 on the second calibration point. The MX-3 will now
display the sound velocity value it has calculated based on the
thickness values that were entered in step 7.
9) The MX-3 is now ready to perform measurements.