Extech Instruments MZ13604 User manual

USER MANUAL
Dual Moisture Meter
Pin and Pinless Moisture Measurements
Model MO55

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Introduction
Thank you for selecting the Extech MO55 Pin and Pinless Dual Moisture Meter. The compact
MO55 takes quick Moisture level reference measurements (in percent %) on wood and building
materials. The MO55 can be used in pinless mode (rear sensor) or in pin mode. The MO55 is
simple to operate and offers measurement digits, audible tones and ‘moisture drop’ icons to
indicate moisture level content.
The MO55 is ideal for building restoration projects and applications where moisture detection on
floors and under carpets is critical. The MO55 is a great tool for analyzing the after-effects of
water leakage behind walls and in ceilings.
This meter is shipped fully tested and calibrated and, with proper use, will provide years of
reliable service. Please visit our website (www.extech.com) to check for the latest version of this
User Guide, Product Updates, Product Registration, and Customer Support.
Features
Displays the moisture level in wood and building materials (wall board, sheet rock, cardboard,
plaster, concrete, and mortar)
Pinless (non-invasive) or Pin modes of operation
Auto zero calibration for Pinless mode
Audible tone rate beeps faster as the moisture level increases (8 tone variations)
‘Moisture drop’ Icons display low, medium and high levels of moisture content
Easy-to-use, compact design
Display Lock freezes reading on display
Auto Power Off after 2 minutes conserves battery power
Complete with protective cap and 9V battery

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Description
Meter Description
1. Protective cover and pin-mode self-test circuit
2. Measurement pins
3. LCD Display
4. Power button
5. Mode (M) Pin/Pinless and Material selection
6. Display Lock/Beeper button
7. Internal sensor (rear)
8. Battery compartment (rear)
Display Description
1. Moisture Drop icons (1 droplet for low moisture content, 2 for medium, and 3 for high)
2. Wood mode
3. Building Material mode
4. Beeper active icon
5. Moisture reading digits
6. Percent moisture unit (relative)
7. Display Lock mode
8. Battery status icon
Button Description
Button
Button name
Description
Power ON-OFF
Press and hold to switch the meter ON or OFF
M
Mode (Material Select)
Select Material (Wood, Building Materials) for
Pin or Pinless mode
/
Display Lock / Beeper control
Short press locks reading on the display
Long press toggles the Beeper ON/OFF

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Operation
Operating Steps
1. For pin mode, carefully remove the protective/test cap to expose the electrode pins.
2. Switch the meter ON by long press of the button. The meter emits audible tones and the
display switches on when the meter powers up. If the meter does not switch on please check
the battery in the rear compartment.
3. Momentary presses of the Mode (M) button step through the following four material modes:
Wood - Pin mode , Building Material - Pin mode , Wood - Pinless mode (icon blinking)
, and Building Material - Pinless mode (icon blinking) .
4. For pin mode, push the electrode pins into the material under test.
5. For pinless mode, with power on, hold the meter in open air
(rear sensor should be clear of hands and any objects) and then
select material (step 3); the meter is now zero-calibrated. Press
the sensor firmly against the surface under test to take a
reading.
6. Observe the displayed reading in percent (%), view the displayed moisture droplet icon
and listen for the audible tones.
1 moisture droplet for low readings; 2 for medium readings; 3 for high readings; refer to the
chart on the back of the meter. Listen for the audible tone (fast beeping for higher readings
and slow beeping for lower readings).There are eight (8) tone variations.
7. Long press of the power button switches the meter off.
Measurement Interpretation Table
PIN MODE
PINLESS MODE
WOOD (%)
BUILDING
MATERIAL (%)
WOOD (%)
BUILDING
MATERIAL (%)
TOTAL RANGE >
5.0~50.0
1.5~33.0
0.0~99.9
0.0~99.9
LOW
5.0~11.9
1.5~16.9
0.0~16.9
0.0~16.9
MEDIUM
12.0~15.9
17.0~17.9
17.0~29.9
17.0~29.9
HIGH
16.0~50.0
20.0~33.0
30.0~99.9
30.0~99.9
Auto Power OFF (APO)
To conserve battery energy the meter automatically switches off after a two-minute period of
inactivity.
CAUTION: The electrode measurement pins are extremely sharp. Use care when
handling this instrument. Cover the pins with the protective cap when not in use.

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Display Lock
Press the Display Lock button to freeze the displayed reading. The icon is visible on the
display when Display Lock is active. Press again to return to the normal operating mode.
Beeper ON/OFF
The beeper defaults to ON. To switch the beeper OFF, press and hold the Display Lock/Audible
Beeper button until the icon disappears. When the beeper is active the audio display icon
will be visible.
Pin-Mode Self-Test
Turn on the meter and set the meter to Pin mode Wood or Building materials and then touch
the electrode pins to the contacts through the holes at the top of the Protective/Test cap.
Expected result: Wood 17.0 to 19.0%; Building 15.5 to 17.5%
When the meter reads outside of these ranges please replace the battery and retry. If the meter
continues to read outside of these ranges, the meter should be returned for service.
Pinless Mode Comparison Measurements
While holding the meter against a known dry surface, turn on the meter. Press the Mode (M)
button to step to the preferred setting, blinking wood or blinking building material icon. The
meter will now read 0% (relative/offset reading). Now move the meter to other areas to test to
find higher levels of moisture.
Maintenance
Battery Replacement
When the battery status icon appears empty or flashing, replace the battery.
1. Remove the rear battery compartment cover by pushing the compartment latch.
2. Replace the 9V battery observing correct polarity.
3. Replace the compartment door securely.
4. Dispose of battery responsibly and within applicable legal regulations.
Never dispose of used batteries or rechargeable batteries in household waste.
As consumers, users are legally required to take used batteries to appropriate collection sites, the
retail store where the batteries were purchased, or wherever batteries are sold.
Disposal: Do not dispose of this instrument in household waste. The user is obligated to take end-of-
life devices to a designated collection point for the disposal of electrical and electronic equipment.
Care and Cleaning
When the instrument is not in use please keep the protective cap in place.
Store the meter in a stable, dust-free environment; out of direct sunlight.
Remove the battery from the instrument if the meter is to be stored for long periods or if
the battery power symbol appears empty (or flashing) on the display.
To clean the meter case, wipe with a damp cloth do not use solvents or abrasives.
To clean the pins, wipe carefully with a damp cloth to remove residue; allow to dry well.

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Specifications
Display LCD with multi-function indicators
Measurement type Relative Moisture Content (%)
Measurement principle Electrical resistance (pins)
Electrical capacitance internal sensor (pinless)
Measurement depth Pinless mode: < 25mm (1 in.)
Auto Calibration Pinless mode in open air
Measurement indication Digital, Moisture Droplet icons (1, 2, or 3 droplets) and audible tone
with 8 levels of intensity indicating low to high moisture readings
Measurement ranges PIN MODE: 5.0~50.0% (wood), 1.4~33.0% (building materials);
PINLESS MODE: 0.0~99.9% (for wood and building materials)
Resolution 0.1%
Accuracy (Pin mode) ± (3% + 5 digits) for ambient conditions 22 oC to 25 oC (72 oF to 77 oF)
Electrode pin length 0.3” (8mm)
Electrode pin type Stainless steel. Integrated, replaceable
Auto Power OFF After approx. two (2) minutes
Power supply One (1) 9V Battery (rear compartment)
Consumption < 40mA
Low Battery indication Battery status icon appears empty or flashing
Operating conditions 5~45oC (41~113oF); 80%RH max.
Storage conditions 0~50oC (32~122oF); 85%RH max.
Dimensions 170 x 65 x 30mm (6.7 x 2.6 x 1.2")
Weight 120g (4.2 oz.) without battery
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All rights reserved including the right of reproduction in whole or in part in any form
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