Extech MN26T Operating Manual

User’s Manual

MiniTecTM Series

Model MN26

(Model MN26T includes temperature probe)

Mini Autoranging MultiMeter

Introduction

Congratulations on your purchase of Extech’s MN26 Autoranging Multimeter. This meter
measures AC/DC Voltage, AC/DC Current, Resistance, Capacitance, Frequency, Duty Cycle,
Temperature, Diode Test and Continuity. Proper use and care of this meter will provide many
years of reliable service.

Safety

International Safety Symbols

Safety Precautions

1. Improper use of this meter can cause damage, shock, injury or death. Read and

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

3. Always remove the test leads before replacing the battery or fuses.

4. Inspect the condition of the test leads and the meter itself for any damage before

5. Do not exceed the maximum rated input limits.

6. Use great care when making measurements if the voltages are greater than 25VAC

7. Always discharge capacitors and remove power from the device under test before

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

9. To avoid electric shock, do not measure AC current on any circuit whose voltage

10. Voltage checks on electrical outlets can be difficult and misleading because of the

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

understand this user manual before operating the meter.

operating the meter. Repair any damage before use.

rms or 35VDC. These voltages are considered a shock hazard.
performing Capacitance, Diode, Resistance or Continuity tests.

exceeds 250V AC.
uncertainty of connection to the electrical contacts. Other means should be used to

ensure that the terminals are not "live".

Specifications

Function Range Resolution Accuracy
DC Voltage
(V DC)

AC Voltage
(V AC)
(40 - 400Hz)
(40 - 200Hz for
400mV, 4V ranges)

DC Current
(A DC)

400mV 0.1mV
4V 0.001V
40V 0.01V
400V 0.1V
600V 1V
400mV 0.1mV
4V 0.001V
40V 0.01V
400V 0.1V
600V 1V
400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
10A 0.01A

±(0.5% reading + 2 digits)
±(1.0% reading + 2 digits)

±(1.5% reading + 2 digits)
±(2.0% reading + 30 digits)
±(1.5% reading + 3 digits)

±(2.0% reading + 4 digits)
±(1.5% reading + 3 digits)

±(2.5% reading + 5 digits)

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Function Range Resolution Accuracy
AC Current
(A AC)
(40 - 400Hz)
(40 - 200Hz for
400µA, 4mA
ranges)
Resistance

Capacitance

Frequency

Duty Cycle 0.1 to 99.9% 0.1%

Temp °F -4 to 1400°F* 1°F
Temp °C -20 to 760°C* 1°C

NOTE: Accuracy is stated at 65oF to 83oF (18oC to 28oC) and less than 70% RH.
NOTE: Temperature range of the temperature probe may be less than the range of the

meter.

Function Maximum Input
V DC, VAC 600V DC/AC
Ohms, Capacitance, Diode, Frequency,
Continuity
mA DC/AC 400mA DC/AC
10A DC/AC 10A DC/AC (30sec. max)

400µA 0.1µA
4000µA 1µA
40mA 0.01mA
400mA 0.1mA
10A 0.01A

400Ω 0.1Ω ±(1.2% reading + 4 digits)
4kΩ 0.001kΩ
40kΩ 0.01kΩ
400kΩ 0.1kΩ
4MΩ 0.001MΩ
40MΩ 0.01MΩ ±(2.0% reading + 3 digits)
4nF 0.001nF
40nF 0.01nF
400nF 0.1nF
4µF 0.001µF
40µF 0.01µF
200µF 0.1µF ±(5.0% reading + 5 digits)

9.999Hz 0.001Hz

99.99Hz 0.01Hz

999.9Hz 0.1Hz

9.999kHz 0.001kHz

99.99kHz 0.01kHz

999.9kHz 0.1kHz

9.999MHz 0.001MHz
Sensitivity: 0.8V rms min. @ 20% to 80% duty cycle and <100kHz;

5Vrms min @ 20% to 80% duty cycle and > 100kHz.

Input Limits

±(1.8% reading + 5 digits)

±(3.0% reading + 7 digits)

±(1.2% reading + 2 digits)

±(5.0% reading + 10digits)
±(5.0% reading + 7 digits)
±(3.5% reading + 5 digits)

±(1.5% reading + 5 digits)
±(1.2% reading + 2 digits)

±(1.5% reading + 4 digits)

±(1.2% reading + 2 digits)
Pulse width: 100µs - 100ms
±(3.0% reading + 3 digits)

(probe effect additional)

250V DC/AC

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Diode Test Test current of 0.3mA maximum, open circuit voltage 1.5V DC

typical

Continuity Check Audible signal will sound if the resistance is less than

approximately 30Ω, test current <0.7mA

Input Impedance 7.5MΩ (VDC and VAC)
Display 4000 count LCD
Overrange indication “OL” is displayed
Polarity Automatic (no indication for positive polarity); Minus (-) sign for

negative polarity.

Measurement Rate 2 times per second, nominal
Auto Power Off Meter automatically shuts down after 15 minutes of inactivity
Low Battery Indication “BAT” is displayed
Batteries Requires two AAA batteries
Fuses mA, µA ranges, 0.5A/250V fast blow
10A range, 10A/250V fast blow
Operating Temperature 32
Storage Temperature -4

o

F to 122oF (0oC to 50oC)

o

F to 140oF (-20oC to 60oC)

Relative Humidity <70% operating, <80% storage
Operating Altitude 7000ft (2000 meters) maximum.
Weight 9.17 oz. (260g).
Size 4.78” x 2.38” x 1.57” (121.5mm x 60.6mm x 40mm)
Safety For indoor use and in accordance with Overvoltage Category

II, Pollution Degree 2. Category II includes local level,
appliance, portable equipment, etc., with transient
overvoltages less than Overvoltage Category III.

Meter Description

1. LCD Display

2. Function switch

3. Function key

4. Range key

5. Temperature jack

6. COM jack

7. 10A jack

8. Positive jack

9. Relative key

10. Data Hold key

Note: Tilt stand, fuse and battery compartment are on rear of unit.

1
4

3

10

9

2

5
6

7

8

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Symbols

AC (alternating current or

voltage)
DC (direct current or voltage)

•))) Continuity
Diode test
mV, V millivolt, volt (voltage)
Ω, kΩ, MΩ ohm, kilohm, megohm

(resistance)

uA, mA, A microamp, milliamp, Amp

(current)

pF, nF, uF picofarad, nanofarad,

Hz kHz hertz, kilohertz (frequency)
% % duty cycle

O

F, OC Degrees Fahrenheit,

AUTO Autorange
BAT Low battery
HOLD Display hold
REL Relative

microfarad (capacitance)

Centigrade (temperature)

Operating Instructions

AC or DC Voltage Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive V jack.

2. Turn the rotary switch to the VAC or VDC position.

3. Touch the test probes to the circuit under test and read the voltage on the display.

AC or DC Current Measurements

CAUTION: Do not make current measurements on the 10A scale for longer than 30

seconds followed by a 15 minute cool down period. Exceeding 30 seconds may cause
damage to the meter and/or the test leads.

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the;
a. Positive uA/mA jack for currents to 400mA
b. Positive 10A jack for currents to 10A

2. Turn the rotary switch to the uA, mA or A position.

3. Touch the test probes in series with the circuit under test and read the current on the
display.

Resistance Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive Ω jack.

2. Turn the rotary switch to the Ω position.

3. Touch the test probes to the circuit or device under test and read the resistance on
the display.

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Capacitance Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive CAP jack.

2. Turn the rotary switch to the CAP position.

3. Touch the test probes to the circuit or device under test and read the capacitance on
the display.

Frequency or Duty Cycle Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive HZ jack.

2. Turn the rotary switch to the Hz/% position.

3. Press the Hz/% key to select “Hz” or “%”.

4. Touch the test probes to the circuit or under test and read the frequency or duty cycle
on the display.

Temperature Measurements

WARNING: To avoid electric shock, disconnect test leads from any source of voltage

before making a temperature measurement. Be sure that the thermocouple has been
removed before changing to any other measurement function.

WARNING: To avoid electric shock, do not probe live circuits with the thermocouple
probe..

1. Insert the type K thermocouple probe into the sub-miniature temperature socket.
(see separate instruction sheet at the end of this manual)

2. Turn the rotary switch to the

3. Read the temperature on the display.

Note: Although the meter specifies the temperature range to be -4 to 1400
the supplied thermocouple’s (Part No. TP870) temperature range is -40 to 482

o

C).

250

o

C or oF position.

o

F (-20 to 760oC)

o

F (-4- to

Continuity Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive Ω jack. Observe polarity.

2. Turn the rotary switch to the •))) position.

3. Press the •))) key to select continuity.

4. Touch the test probes to the circuit or device under test. If the resistance is less than
approximately 30Ω the buzzer will sound and the resistance appears on the display.

Diode Measurements

1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the positive diode jack.

2. Turn the rotary switch to the •))) position.

3. Press the •))) key to select diode.

4. Touch the test probes to the diode under test. Forward voltage will indicate 0.4V to

0.7V. Reverse voltage will indicate “OL”. Shorted devices will indicate near 0mV and
an open device will indicate “OL” in both polarities.

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Manual Ranging

The meter powers on in the autoranging mode. Press the Range key to go to manual
ranging. Each press of the range key will step to the next range as indicated by the units
and decimal point location. Press and hold the Range key for one second to return to
autoranging.

Data Hold

Press the Data Hold key to freeze the reading in the display. “HOLD” will appear in the
LCD. Press the key again to release the display.

Relative Measurements

The relative measurement feature allows you to make measurements relative to a stored
reference value. A reference voltage, current, etc. 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 any 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 return to normal operation.

Auto Off

The auto off feature will turn the meter off after 15 minutes of inactivity (Range switch or a
key has not been turned or pressed). A beep will warn the user shortly before the auto off
feature activates.

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Maintenance

WARNING: To avoid electric shock, disconnect the test leads from any source of voltage
before removing the battery/fuse cover.

WARNING: To avoid electric shock, do not operate your meter until the battery/fuse
cover is in place and fastened securely.

This Multimeter is designed to provide years of dependable service, if the following care
instructions are performed.

1. Keep the meter dry.

2. Use and store the meter in mild ambient conditions. Temperature extremes can
shorten the life of the electronic parts and distort or melt plastic parts.

3. Handle the meter gently. Dropping it can damage the electronic parts or the case.

4. Keep the meter clean. Wipe the case occasionally with a damp cloth. DO NOT use
chemicals, cleaning solvents or detergents.

5. Use only fresh batteries of the recommended size and type. Remove old or weak
batteries so they do not leak and damage the unit.

6. If the meter is to be stored for a long period of time, the batteries should be removed
to prevent damage to the unit.

Battery Replacement

WARNING: To avoid electric shock, disconnect the test leads from any source of

voltage before removing the battery/fuse cover.

1. Disconnect the test leads from the meter.

2. Remove the rubber holster (if in place).

3. Open the battery door by removing the screw using a Phillips
head screwdriver.

4. Insert the new batteries into the battery holder, observing the
correct polarity.

5. Replace the battery door and secure with the screw.

Fuse Replacement

WARNING: To avoid electric shock, disconnect the test leads from any source of

voltage before removing battery/fuse cover.

1. Disconnect the test leads from any circuit being measured.

2. Remove the rubber holster (if in place).

3. Open the fuse cover by removing the screw on the rear cover using a Phillips
screwdriver.

4. Remove the rear cover.

5. Remove the old fuse by gently pulling up on it.

6. Install the new fuse by gently pushing it into the holder.

7. Always use a fuse of the proper size and value (0.5A/250V fast blow, or 10A/250V
fast blow).

8. Replace the fuse door and secure with the screw.

A UL mark does not indicate that this product has been evaluated for the accuracy of its
readings.

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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 Departm ent at (781) 890­7440 ext. 210 for authorization or visit our website at www.extech.com (click on ‘Contact Extech’ and go to ‘Service
Department’ to request an RA number). 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 i n 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 complete repair and calibration services for all of the products we sell. For
periodic calibration, NIST certification or repair of any Extech product, call customer service
for details on services available. Extech recommends that calibration be performed on an
annual basis to insure calibration integrity.

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

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

Support line [phone]

Copyright © 2005 Extech Instruments Corporation.

All rights reserved including the right of reproduction

in whole or in part in any form.



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MN26T V4.0 05/05

Instruction Sheet

Model TP870
Type K Bead Wire Thermocouple Probe

WARNING: To avoid electric shock, do not probe into or near live electrical circuits with the

Sensor Type Type K thermocouple (Chromel – Alumnel)
Temperature range -40 to 482
Lead length 39” (1m)
Connector subminiature
Note: This probe is not UL listed

thermocouple probe..

o

F (-40 to 250oC)

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MN26T V4.0 05/05