Extech Instruments MO257 User manual

User's Guide
Pinless Moisture Meter
Model MO257
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Introduction
Congratulations on your purchase of the Extech MO257 Pinless Moisture Meter. The
pinless moisture sensor monitors the moisture in wood and other building materials without
causing surface damage. High frequency sensing technology allows the meter to take non-
invasive moisture measurements. User programmable alarms alert the user if moisture
measurements exceed alarm set-points. This meter is shipped fully tested and calibrated
and, with proper use, will provide years of reliable service.
Meter Description
1. Measurement sensor
2. Power ON-OFF button
3. LCD display
4. Measure (MEAS) button
5. UP and BACKLIGHT button
6. SET button
7. DOWN button
Battery compartment located on rear of unit
LCD Display
1. Low Battery icon
2. Main LCD display
3. MAX reading
4. MIN reading
5. HOLD function
6. Measurement alert
7. MAX mode icon
8. MIN mode icon
Battery Replacement
1. Turn off the meter
2. Remove the Philips head screw located on the rear of the unit
3. Lift off the rear battery cover
4. Replace the three (3) ‘AAA’ 1.5V batteries
5. Secure the rear battery cover
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Operation
Pinless Moisture Measurements
1. Press the power button to turn the meter on.
2. Before first use the meter must be calibrated to a known dry area as described below.
3. To calibrate, press the MEAS button immediately after powering the meter. The
display will audibly beep and visually flash the CAL display icon. Keep the
measurement sensor at least 3 to 4” (8 to 10 cm) from any object during calibration.
4. When the calibration is complete the beeping and flashing stop. The calibration
reading must not exceed 0.5. If so, re-calibrate ensuring that hands or other objects
are kept clear of the measurement sensor.
5. The meter should be calibrated whenever it is moved from one measurement area to
another.
6. To take a measurement, hold the meter and position the sensor so that it is very near
or directly touching the surface under test. The meter can sense moisture to a depth
of 0.79 to 1.57” (20 to 40mm).
7. IMPORTANT NOTE: The position of the hand can greatly affect a reading. Do not
move or reposition the hand that holds the meter while taking measurements or when
calibrating the unit.
8. The LCD indicates a relative moisture reading in numeric digits from 0.0 to 100.0 and
with programmable alarm alerts (DRY, RISK, and WET).
9. Press the MEAS button to hold (freeze) a reading on the LCD (the HOLD icon will
appear on the LCD). The meter will hold the reading for 30 seconds before
automatically shutting the meter down.
10. The MAX and MIN display areas indicate the highest and lowest readings
encountered since the measurement session was started.
11. If the battery symbol appears or if the meter does not switch ON, replace the
batteries.
Alarm Settings
Two high alarm points can be set for Moisture measurements: A RISK Alarm (0 to 50
setting range with a default setting of 30 units) and a WET Alarm (50 to 100 setting range
with a default setting of 60 units).
Moisture Alarm Setup Procedure:
1. Press the SET button. The RISK display icon will appear flashing on the LCD
indicating that a RISK alarm can now be programmed.
2. Use the up/down buttons to select the desired RISK Alarm value.
3. Press the SET button when the desired setting is displayed.
4. The WET icon will appear flashing on the LCD indicating that the WET Alarm is ready
to be programmed.
5. Use the up/down buttons to select the desired Wet Alarm setting.
6. Press SET to complete the programming.
7. Now, if the moisture measurement is higher than the RISK setting, the meter will beep
once every two seconds and if the moisture measurement is higher than the WET
setting the meter will beep four times per second.
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Auto Power Off
To conserve battery energy, the meter will enter a sleep mode after approx. 30 minutes of
inactivity. Press the power button to wake the meter.
Backlit LCD
Press the up/backlight button to switch the backlighting ON or OFF.
Specifications
Function Range Accuracy
Moisture Range 0.0 to 100.0 Relative only
Measurement Depth 0.79 to 1.57” (20 to 40mm)
Display type Backlit LCD
Display digits Three (3) numeric displays; each displaying from 0.0 to 100.0
Display icons HOLD, DRY, RISK, WET, MIN, MAX and low battery icon
Operating Temperature 40 to 110°F (4 to 43°C)
Operating Humidity 90%, 32-86°F (0-30°C), 75%, 86-104°F (30-40°C),
45%, 104-122°F (40-50°C)
Power Supply Three (3) 1.5V ‘AAA’ batteries
Auto Power Off (APO) After 30 minutes of inactivity
Dimensions 9.2 x 2.5 x 1.1” (235 x 63 x 28mm)
Weight 7.7oz (218g)
Moisture Comparison Table (typical)
Material Display units Moisture status
Gypsum < 30 DRY
30 - 60 RISK
> 60 WET
Cement < 25 DRY
25 - 50 RISK
> 50 WET
Wood < 50 DRY
50 - 80 RISK
> 80 WET
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Support line [phone]
Technical Support: Extension 200; E-mail: [e-mail]
Repair & Returns: Extension 210; E-mail: [email protected]
Product specifications subject to change without notice
For the latest version of this User Guide, Software updates, and other
up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Corporation, 285 Bear Hill Road, Waltham, MA 02451
ISO 9001 Certified
Warranty
EXTECH INSTRUMENTS CORPORATION (A FLIR COMPANY) warrants this instrument to be free of
defects in parts and workmanship for one year from date of shipment (a six month limited warranty
applies to sensors and cables). If it should become necessary to return the instrument for service during
or beyond the warranty period, contact the Customer Service Department at [phone] ext. 210 for
authorization or visit our website www.extech.com for contact information. A Return Authorization (RA)
number must be issued before any product is returned to Extech. The sender is responsible for shipping
charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not
apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of
specification, improper maintenance or repair, or unauthorized modification. Extech specifically
disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable
for any direct, indirect, incidental or consequential damages. Extech's total liability is limited to repair or
replacement of the product. The warranty set forth above is inclusive and no other warranty, whether
written or oral, is expressed or implied.
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also
provides NIST certification for most products. Call the Customer Care Department for
information on calibration services available for this product. Extech recommends that
annual calibrations be performed to verify meter performance and accuracy.
Copyright ©2010 Extech Instruments Corporation (a FLIR company)
All rights reserved including the right of reproduction in whole or in part in any form.
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