MO220 Datasheet, PDF (5/15 Pages) Extech Instruments Corporation. – Moisture Meter

Manual Accuracy Check
There are two (2) sets of calibration poles located inside the meter’s protective cover.
One set is for the 18% calibration and the other is for the 26% calibration, as marked
inside the cover.
When checking the calibration, the A scale should be selected and the temperature
probe must be disconnected.
Touch the two measurement pins to the 18% calibration nodes and view the
measurement on the meter display. Do the same for the 26% calibration.
When correctly calibrated, the instrument will register %H2O values in the range of
17.7 to 18.3 (18% calibration) and in the range of 25.5 to 26.5 (26% calibration).
If the tolerance exceeds ±1 the instrument must be recalibrated.
Care and Maintenance
When the instrument is not in use, keep it in its pouch together with its accessories. Store
the kit in a stable, dust-free environment out of direct sunlight. Remove the batteries from
the instrument if it is to be stored for periods of more than one month, or when the low
battery power symbol appears on the display. Check the condition of accessories used
with the instrument on a regular basis and replace them if they become worn or damaged.
Battery replacement
When the low battery icon appears on the display, replace the battery as soon as practical.
1. Remove the rear battery compartment screw.
2. Remove the battery compartment door
3. Replace the two (2) ‘AAA’ 1’5V batteries
4. Replace the compartment door and secure the screw before using the meter.
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Model MO220 V1.1 10/07