Zero Calibration - Tru-Test EC-10 User Manual

6 Once the counter reads zero, move the plate meter up the full length of the
shaft. The colon will disappear once it passes 9 and enters "clicks" mode.
At the full height the display should read approximately "50" which is 50
half centimetres. The plate meter has now been calibrated.
7 Switch off when you have finished, and then back on again without
pressing any buttons.
8 Test the zero calibration by raising and lowering the plate all the way to the
bottom several times. A beep should sound and the kg DM/ha displayed as
the plate falls. If it does not, repeat the steps above and retest.
9 When you have finished calibrating the plate meter, replace the rubber
bung over the zero adjustment screw.
If the calibration fails to hold, then the potentiometer, which the cog drives, is
probably faulty and will need replacing. This can occur with excessive wear often
compounded by dust and dirt entering the dry bearing of the potentiometer.
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