Checkline TI-MVX - Manual (Page 34)

2) Apply a drop of couplant on the transducer. Place the transducer in steady
contact on the known thickness location. Be sure that the reading is stable and
the repeatability indicator, located 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.
3) Use the UP and DOWN arrow keys to scroll through the sub menu items until
ONE POINT is highlighted.
4) Press the ENTER key to display the Digits Edit Box.
5) Press the UP and DOWN arrow keys to scroll the highlighted value.
6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.
7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.
8) Press the OK key to calculate the velocity and return to the menu screen,
or ESC to cancel entering the velocity.
9) Finally, press the MEAS key to return to the measurement screen and begin
taking readings.
Note: CHECK YOUR CALIBRATION! Place the transducer back on the
calibration point. The thickness reading should now match the known thickness.
If the thickness is not correct, repeat the steps above.
Two Point Calibration
Note: Be sure that a probe zero has been done prior to performing this calibra-
tion procedure.
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7) Repeat steps 5 & 6 until the Delay number is correctly displayed.
8) Press the OK key to set the Delay and return to the menu screen, or ESC to
cancel entering the Delay.
9) Finally, press the MEAS key to return to the measurement screen and begin
taking readings.
7.4 Gain
The gain, or amplification of the return echoes, can be adjusted over a wide
range. The setting of the gain is crucial in order to obtain valid readings during
the measurement process. Too much gain may result in erroneous measure-
ments, by detecting on noise rather than the actual material back wall itself. Too
little gain may result in detection on an undesirable section of the waveform. It
may also result in lack of detection on internal flaws or pits. The gain can easily
be compared to the volume control of a home stereo system. If you turn it up too
much, you can’t hear the music clearly. If it’s turned down too much, you can’t
hear it at all.
Adjusting the Gain using the Hot Menus
1) Press the MEAS key once to activate measure
menu items. Press the MEAS key multiple times to
move right, and the ESC key multiple times to move
left until the GAIN cell is highlighted.
2) Press the UP, DOWN, LEFT, and RIGHT arrow keys
to scroll the highlighted value.
3) Alternatively, press the ENTER key to display the
Digits Edit Box.
4) Press the UP and DOWN arrow keys to scroll the
highlighted value.
5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.
6) Repeat steps 4 & 5 until the GAIN value is correctly displayed.
7) Press the OK key to return to the measurement screen, or ESC to cancel
entering the GAIN.
The user can also access and adjust the gain from the tabbed menus. However,
this method is more tedious than making the adjustments using the Hot Menus. :
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