Extech DM110 Operating Manual

User’s Guide

Pocket Multimeter
4000 Count Autoranging DMM
Model: DM110

Warranty

EXTECH INSTRUMENTS CORPORATION 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 on 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 at 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.

Copyright © 2006Extech Instruments Corporation. All rights reserved
including the right of reproduction in whole or in part in any form.

DM110 V2.1 04/06

Safety

International Safety Symbols

Safety Precautions

1. Improper use of this meter can cause damage, shock, injury or
death. Read and understand this users manual before
operating the meter.

2. Make sure any covers or battery doors are properly closed and
secured.

3. Always disconnect the test leads from any voltage source
before replacing the battery or fuses.

4. Do not exceed the maximum rated input limits.

5. Use great care when making measurements if the voltages are
greater than 25VAC rms or 35VDC. These voltages are
considered a shock hazard.

6. Always discharge capacitors and remove power from the
device under test before performing Capacitance, Diode,
Resistance or Continuity tests.

7. Remove the battery from the meter if the meter is to be stored
for long periods.

This symbol, adjacent to another symbol or
terminal, indicates the user must refer to the manual
for further information.

This symbol, adjacent to a terminal, indicates that,
under normal use, hazardous voltages may be
present.

Double insulation

Description

Meter Description

1. 3 3/4 Digit (4000 count)

2. RELATIVE button

3. SELECT button

4. DATA HOLD button

5. Hz/DUTY button

6. Function switch

7. Rubber holster

8. Test leads

Specifications

Electrical Specifications

Function Range Accuracy

DC Voltage

AC Voltage
(40-400Hz)

(50-60 Hz)

Resistance

Capacitance

Frequency 9.999Hz, 99.99Hz,

Duty Cycle 0.1-99%

Max input voltage 500V AC/DC
Input Sensitivity, 10Vrms min. <9.999KHz

(Frequency Ranges) 40Vrms min. >99.99KHz
Diode Test Test current 1mA max., open circuit voltage

Continuity Check Audible signal if the resistance is < 60Ω
Display 4000 count 3 ¾ digit LCD
Over range indication LCD displays “OL”
Polarity Minus (-) sign for negative polarity.
Low Battery Indication “BAT” symbol indicates low battery

Battery CR2032 3V Lithium
Operating Temperature 32
Storage Temperature 14
Weight 1.7oz (50g)
Size 4.25x2.2x.5” (108x56x11.5mm)
Standard IEC1010 CAT II 600V Pollution degree II,

400.0mV

4.000V, 40.00V,

400.0V,500V

4.000V, 40.00V

400.0V, 500V

40.00mA DC Current

400.0mA

40.00mA AC Current

400.0mA

400.0Ω, 4.000kΩ,

40.00kΩ, 400.0kΩ

4.000MΩ ±(5.0% rdg + 5d)

40.00MΩ ±(10.0% rdg + 5d)

4.000nF

40.00nF

400.0nF

4.000µF, 40.00µF,

200.0µF

999.9Hz, 9.999kHz,

99.99kHz, 999.9kHz,
10MHz

of 1.5V typical

condition.

o

F to 104oF (0oC to 40oC)

o

F to 122oF (-10oC to 50oC)

CE Approved

±(0.7% rdg + 3d)

±(1.0% rdg + 3d)

±(1.3% rdg + 3d)

±(1.0% rdg + 10d)

±(2.3% rdg + 5d)

±(2.0% rdg + 5d)

±(2.5% rdg + 10d)

±(2.0% rdg + 5d)

±(5.0% rdg + 0.3nF)

±(5.0% rdg + 30d)

±(3.0% rdg + 15d)

±(10.0% rdg + 15d)

±(2.0% rdg + 5d)

±(2.0% rdg + 5d)

Operation

AC or DC Voltage Measurement

1. Set the function switch to the “AC/DCV” position

2. Press the SELECT button to select AC or DC voltage
measurement

3. Touch the test probe tips to the circuit under test. Be sure to
observe the correct polarity (red lead to positive, black lead to
negative).

4. Read the voltage on the display

Resistance/Continuity Measurement

WARNING: To avoid electric shock, disconnect power to the unit

under test and discharge all capacitors before taking any
resistance measurements. Remove the batteries and unplug the
line cords. Never measure continuity on circuits or wires that
have voltage on them.

1. Set the function switch to the “  •))) ” position.

2. Connect the test leads to the circuit to be measured.

3. Read the value on the display.

4. For Continuity tests, press the SELECT button until the “•)))“
symbol appears in the display.

5. If the resistance is less than 60 ohms, an audible tone will sound.

Capacitance Measurement

WARNING: To avoid electric shock, disconnect power to the unit

under test and discharge all capacitors before taking any
capacitance measurements. Remove the batteries and unplug
the line cords. Never measure continuity on circuits or wires that
have voltage on them.

1. Set the function switch to the “  •))) ” position.

2. Press the SELECT button until “nF” appears in the display.

3. Press the RELATIVE button to zero the display

4. Connect the test leads to the capacitor to be measured.

5. Read the value on the display.

Diode Test

WARNING: To avoid electric shock, do not test any diode that

has voltage on it.

1. Set the function switch to “  •))) “position.

2. Press the SELECT button once to enter Diode Test. The “ “

symbol will appear in the display.

3. Touch the test probe tips to the diode or semiconductor junction

you wish to test. Note the meter reading.

4. Reverse the test lead polarity by reversing the red and black

leads. Note this reading.

5. The diode or junction can be evaluated as follows:

A. If one reading shows a value and the other reading shows OL,

the diode is good.
B. If both readings show OL, the device is open.
C. If both readings are very small, or 0, the device is shorted

AC/DC Current Measurement

1. Set the function switch to the “mA AC/DC” position.

2. Press the SELECT button to measure AC or DC mA.

3. Remove power from the circuit under test and open the circuit at
the point where you wish to measure current.

4. Touch the black test probe tip to the negative side of the circuit
and touch the red test probe tip to the positive side of the circuit.

5. Apply power to the circuit.

6. Read the value on the display

Frequency/Duty Cycle Measurement

1. Set the function switch to the “HZ/DUTY” position.

2. Press the Hz/DUTY button once to display Duty Cycle %. Pressing
the button again will toggle the display to frequency (Hz).

3. Touch the test probe tips to the circuit under test. Be sure to
observe the correct polarity (red lead to positive, black lead to
negative).

4. Read the value on the display.

Features

Relative Button
The relative measurement feature allows you to make measurements

relative to a stored reference value. A reference voltage can be
stored and measurements made in comparison to that value. The
displayed value is the difference between the reference value and the
measured value.

1. Perform the measurement as described in the operating
instructions.

2. Press the RELATIVE button to store the reading in the display and
the "REL" indicator will appear on the display.

3. The display will now indicate the difference between the stored
value and the measured value.

4. Press the RELATIVE button to exit the relative mode.

Note: The Relative function does not operate in the Frequency
function.

Data Hold Button

The Data Hold function allows the meter to “freeze” a measurement
for later reference

1. Press the “DATA HOLD” button to “freeze” the display, the
“HOLD” indicator will appear.

2. Press the “DATA HOLD” button to return to normal operation.

Auto Power Off

1. To save power, the display automatically turns off in 30 minutes.

2. Press the SELECT button to turn display back on.

3. To cancel Auto Power Off, set the function switch to the off
position. Hold down the SELECT button and turn the function
switch to the desired position and release the SELECT button after
3 seconds.

Maintenance

WARNING: Disconnect the test leads from any source of voltage
before removing the back cover or the battery/fuse door. Do not
operate your meter until the rear housing is in place and fastened
securely.

Replacing the Battery

1. Remove the rubber holster (if in place)

2. Remove Philips head screw and lift off the rear housing of the
meter.

3. Replace old battery with fresh CR2032 type button battery.

4. Replace the rear cover and secure the screw.



Technical support: Extension 200; E-mail: [e-mail]

Support line [phone]

Repair & Returns: Extension 210; E-mail: [e-mail]

Product specifications subject to change without notice

For the latest version of this User’s Guide, Software updates, and other

up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451