MO220 Datasheet, PDF (4/15 Pages) Extech Instruments Corporation. – Moisture Meter

Operation
CAUTION: The electrode measurement pins are extremely sharp. Use
care when handling this instrument. Cover the pins with the protective cap
when the instrument is not in use.
Basic Measurement Instructions
1. Remove the cap to expose the needle electrodes OR connect the heavy duty moisture
probe socket on the right hand side of this instrument
2. Switch the meter ON by pressing the button.
3. Select the appropriate wood calibration scale A, B, C, E, F, G, H or J (see the Wood
Calibration Tables later in this guide) using the button.
4. Push the needle pins or the heavy duty moisture probe pins into the wood and observe
the reading.
5. Press and hold the power button to shut the meter off.
Manual Temperature Correction (for use without the Temperature Probe)
The instrument is calibrated for wood at 68°F (20°C). In general, wood that is warmer than
68°F (20°C) will give higher readings and wood colder than 68°F (20°C) will give lower
readings. An approximate manual correction of 0.5% moisture content per 9°F (5°C) may
be subtracted from wood that is above 68°F (20°C). For wood that is below 68°F (20°C), a
manual correction of 0.5% moisture content per 9°F (5°C) may be added to the measured
value.
Automatic Temperature Correction ATC (for use with the Temperature Probe)
1. Switch the instrument on and select the appropriate wood calibration scale as detailed
earlier.
2. Using a hammer and nail of a nominal 3 mm diameter, make a hole in the wood to be
tested.
3. Remove the nail and push the Temperature Probe into the hole until the tip is at the
required depth.
4. Connect the Temperature Probe into the instrument via the Temp socket.
5. Measure the wood as described earlier to obtain the automatically temperature
corrected (ATC) moisture value.
6. To read the current temperature of the wood press the T button, the LCD will display
the temperature.
7. Press the T button again to change the C/F unit of measure.
8. Press the button to display moisture value again.
Auto Power OFF
The meter can automatically turn itself off after several minutes. This is to conserve on
battery energy. The user can select the period of time the meter must remain idle before
turning itself off (1 through 9 minutes). The user can also elect to disable the automatic
power off feature (select 00).
1. With the meter ON, simultaneously press the power and the right arrow
buttons. The current time period will appear.
2. While continuing to hold the power button, use the right arrow button to select
the desired time period. Select ‘00’ to disable this feature.
3. Release both buttons when the desired value is on the LCD.
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Model MO220 V1.1 10/07