Checking Calibration - General MMD4E User Manual

To power off the meter, press the
more than 2 seconds.
To silence the beeper
button for >3 seconds. This will disable the beeper until the
meter is powered off. The beeper will automatically be re-
enabled when the meter is powered on again.

CHECKING CALIBRATION

You can verify the accuracy of the MMD4E's readings by
manually checking its calibration at any time. To do so:
1. Remove the black rubber protective sleeves from the test pins.
2. Remove the pin cap and note the small circuit board attached
to the inside of its rear wall. The rear wall also has two small
holes (left photo below) that provide access to terminals on
the circuit board. The circuit board contains a resistor whose
fixed value can be used to simulate a precise moisture level
and therefore check the calibration of the meter.
3. Power on the meter and push the test pins into the
calibration holes (right photo below). If the meter is properly
calibrated, the displayed reading will be 18.3% ± 1% in
Wood Measurement mode. If you do not obtain a reading
within this range and your meter is still under warranty, call
General's Customer Service Department at 212-431-6100
to arrange to return the meter for service or replacement.
6
at any time, press and hold the HOLD
button and hold it for