Dakota Ultrasonics MINI--MAX - Manual (Page 140)

Dakota Ultrasonics
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1) 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 TUNE menu is highlighted and displaying the submenu
items.
2) Use the UP and DOWN arrow keys to scroll through the sub menu
items until GAIN is highlighted.
3) Press the LEFT and RIGHT arrow keys to scroll the value. When the
correct Gain is being displayed, proceed to step 8.
4) Alternatively, 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 Gain value is correctly displayed.
8) Press the OK key to set the Gain and return to the menu screen, or
ESC to cancel entering the Gain.
9) Finally, press the MEAS key to return to the measurement.
12.5 Threshold
The Threshold is the level (sensitivity) of the signal amplitude required to trigger
detection. This level can be used in conjunction with the gain. Example:
suppose the user is not detecting on the first cycle of the waveform because the
amplitude of the first cycle is not large enough to break the current threshold.
Either the Threshold can be decreased (lower sensitivity), or the Gain increased
to cause a detection on the first cycle. This is also very important when the
reference length is being measured. If the threshold is set so that the amplitude
of the signal is just barely reaching the threshold, it should be decreased. If the
user does not increase it at that time, when the fastener is put under a load, the
same peak jumps can occur. Even though the threshold can be adjusted at a