407777 Datasheet, PDF (5/8 Pages) Extech Instruments Corporation. – Heavy Duty Wood Moisture Meter

Wallboard Moisture Measurements
Unlike wood types which have known densities, wallboard does not. Consequently it is not
possible to get an absolute moisture content reading.
The following procedure can be used to make relative or comparative measurements of
the moisture content in wallboard.
1. Turn ON the meter.
2. Select Material Group 1 by pressing the Material Select button.
3. Insert the sensor's test pins into a known dry area of wallboard. Insertion should be to
at least a 0.08" (2mm) depth. The meter display will now indicate moisture content in
%. Note this ‘dry’ reading.
4. Insert the sensor's test pins into the wallboard under test. Insertion should be to at
least a 0.08" (2mm) depth. The meter display will now indicate moisture content in %.
Note this ‘moist’ reading.
5. Compare the ‘dry’ wallboard reading with the ‘moist’ wallboard reading to determine the
moisture content of the wallboard area under test.
Temperature Compensation
This meter is calibrated for use at ambient temperature: 68^oF (20^oC). When the
temperature is above or below this value, manual temperature compensation should be
performed to maintain meter measurement accuracy. Follow these steps:
1. Check that the RECORD function is not engaged (‘REC’ display icon is off).
2. Use the TEMPERATURE ADJUST buttons to increase (left button) or decrease (right
button) the temperature display to match the new temperature (in ^oC). The
temperature is adjustable in 1 degree steps.
3. The value will be stored after 4 seconds. Temperature compensation adjustments are
not stored in memory when the meter is turned OFF however.
Data Hold
To freeze the LCD display reading, press the HOLD key. The 'DH' icon will appear on the
LCD. Press the HOLD key again to return to normal operation (the 'H' hold icon will switch
OFF).
Maximum (MAX) and Minimum (MIN) Record and Recall
To keep track of the highest (MAX) and lowest (MIN) measurements, follow the procedure
below:
1. Press the RECORD button to begin tracking the highest and lowest readings. The REC
display icon will appear on the LCD.
2. Press the RECALL key when it is desired to view the highest reading since the
RECORD button was pressed. The MAX icon will appear on the display and the
reading shown will be the highest reading encountered since the RECORD key was
pressed.
3. Press the RECALL key again to view the lowest reading (MIN).
4. To exit this mode of operation, press the RECORD key again. The REC, MAX, and
MIN icons will switch off.
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Model 407777 Version 2.2 Jan 04