User's Guide

Digital Multimeter plus IR Thermometer

Extech 450

Patented

99 Washington Street

Melrose, MA 02176

Phone

781-665-

1400

Toll Free 1-800-517-8431

Visit us at www.T

estEquipmentDepot.com

Introduction

Congratulations on your purchase of the Extech 450 (part number EX450) Autoranging

Multimeter plus IR Thermometer. This meter measures AC/DC Voltage, AC/DC Current,

Resistance, Capacitance, Frequency, Duty Cycle, Diode Test, and Continuity plus Non-

Contact IR Temperature. Proper use and care of this meter will provide many years of reliable service.

Safety

International Safety Symbols

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

WARNING

CAUTION

MAX

600V

This WARNING symbol indicates a potentially hazardous situation, which if not avoided, could result in death or serious injury.

This CAUTION symbol indicates a potentially hazardous situation, which if not avoided, may result damage to the product.

This symbol advises the user that the terminal(s) so marked must not be connected to a circuit point at which the voltage with respect to earth ground exceeds (in this case) 600 VAC or VDC.

This symbol indicates there is a potential hazard from a laser light source.

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CAUTIONS



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



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



Inspect the condition of the test leads and the meter itself for any damage before operating the meter. Repair or replace any damage before use.



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



Warning! This is a class A equipment. This equipment can cause interferences in the living quarters; in this case the operator can be required to carry out adequate measures.



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



Voltage checks on electrical outlets can be difficult and misleading because of the uncertainty of connection to the recessed electrical contacts. Other means should be used to ensure that the terminals are not "live".



If the equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.



This device is not a toy and must not reach children’s hands. It contains hazardous objects as well as small parts that the children could swallow. In case a child swallows any of them, please contact a physician immediately



Do not leave batteries and packing material lying around unattended; they can be dangerous for children if they use them as toys



In case the device is going to be unused for an extended period of time, remove the batteries to prevent them from training



Expired or damaged batteries can cause cauterization on contact with the skin.

Always, therefore, use suitable hand gloves in such cases



See that the batteries are not short-circuited. Do not throw batteries into the fire.



Do not directly view or direct the laser pointer at an eye.

Low power visible lasers do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time

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OVERVOLTAGE CATEGORY III

This meter meets the IEC 610-1-2001 standard for OVERVOLTAGE CATEGORY III. Cat III meters are protected against overvoltage transients in fixed installation at the distribution level. Examples include switches in the fixed installation and some equipment for industrial use with permanent connection to the fixed installation.

SAFETY INSTRUCTIONS

This meter has been designed for safe use, but must be operated with caution. The rules listed below must be carefully followed for safe operation.

1.

NEVER apply voltage or current to the meter that exceeds the specified maximum:

V DC or V AC mA AC/DC

A AC/DC

Function

Resistance, Diode Test, Continuity

Temperature

Input Protection Limits

Maximum Input

1000VDC/750AC, 200Vrms on 400mV range

500mA 250V fast acting fuse

20A 250V fast acting fuse(30 seconds max every

15 minutes)

250Vrms for 15sec max

60V DC/24V AC

2.

USE EXTREME CAUTION when working with high voltages.

3.

DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth ground.

4.

NEVER connect the meter leads across a voltage source while the function switch is in the current, resistance, or diode mode. Doing so can damage the meter.

5.

ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistance or diode tests.

6.

ALWAYS turn off the power and disconnect the test leads before opening the covers to replace the fuse or batteries.

7.

NEVER operate the meter unless the back cover and the battery and fuse covers are in place and fastened securely.

8.

NEVER look directly at the laser light source or aim the pointer at an eye.

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µ m k

M

AC

DC

ºF

ºC

Controls and Jacks

1. IR Thermometer and laser pointer

2. 2000 count LCD display

3. HOLD button

4. SELECT button

5. Function switch

6. mA, uA and A input jacks

7. COM input jack

8. Positive input jack

9. MAX hold button (voltage and current)

10. BACKLIGHT button

11. Laser pointer button

12. Protective holster

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

Symbols and Annunciators

•))) Continuity

Diode test

Laser pointer

Battery status

Test lead connection error micro (10

-6

) (amps) milli (10

-3

) (volts, amps) kilo (10

3

) (ohms) mega (10

6

) (ohms)

Alternating current

Direct current

Degrees Fahrenheit

Degrees Centigrade

A



V

Amps

Ohms

Volts

AUTO Autoranging

HOLD Display hold

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Operating Instructions

WARNING : Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and should be measured with great care.

1. ALWAYS turn the function switch to the OFF position when the meter is not in use.

2. If “OL” appears in the display during a measurement, the value exceeds the range you have selected. Change to a higher range.

NOTE: On some low AC and DC voltage ranges, with the test leads not connected to a device, the display may show a random, changing reading. This response is normal and is caused by the high-input sensitivity. The reading will stabilize and give a proper measurement when connected to a circuit.

DC VOLTAGE MEASUREMENTS

CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or

OFF. Large voltage surges may occur that can damage the meter.

1. Set the function switch to the green V position.

2. Press the SELECT button to indicate “DC” on the display.

3. Insert the black test lead banana plug into the negative COM jack.

Insert the red test lead banana plug into the positive V jack.

4. Touch the black test probe tip to the negative side of the circuit.

Touch the red test probe tip to the positive side of the circuit.

5. Read the voltage in the display.

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AC VOLTAGE MEASUREMENTS

WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the live parts inside some 240V outlets for appliances because the contacts are recessed deep in the outlets. As a result, the reading may show 0 volts when the outlet actually has voltage on it. Make sure the probe tips are touching the metal contacts inside the outlet before assuming that no voltage is present.

CAUTION: Do not measure AC voltages if a motor on the circuit is being switched ON or

OFF. Large voltage surges may occur that can damage the meter.

1. Set the function switch to the green V position.

2. Press the SELECT button to indicate “ AC ” on the display.

3. Insert the black test lead banana plug into the negative COM jack.

Insert red test lead banana plug into the positive V jack.

4. Touch the black test probe tip to the neutral side of the circuit.

Touch the red test probe tip to the “hot” side of the circuit.

5. Read the voltage in the display.

DC CURRENT MEASUREMENTS

CAUTION: Do not make current measurements on the 20A scale for longer than 30 seconds. 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.

2. For current measurements up to 2000µA DC, set the function switch to the yellow µA position and insert the red test lead banana plug into the µA/mA jack.

3. For current measurements up to 200mA DC, set the function switch to the yellow mA position and insert the red test lead banana plug into the µA/mA jack.

4. For current measurements up to 20A DC, set the function switch to the yellow A range and insert the red test lead banana plug into the A jack.

5. Press the SELECT button to indicate “ DC ” on the display.

6. Remove power from the circuit under test, then open up the circuit at the point where you wish to measure current.

7. Touch the black test probe tip to the negative side of the circuit.

Touch the red test probe tip to the positive side of the circuit.

8. Apply power to the circuit.

9. Read the current in the display.

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AC CURRENT MEASUREMENTS

CAUTION: Do not make current measurements on the 20A scale for longer than 30 seconds. 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.

2. For current measurements up to 2000µA AC, set the function switch to the yellow µA position and insert the red test lead banana plug into the µA/mA jack.

3. For current measurements up to 200mA AC, set the function switch to the yellow mA position and insert the red test lead banana plug into the µA/mA jack.

4. For current measurements up to 20A AC, set the function switch to the yellow A range and insert the red test lead banana plug into the A jack.

5. Press the SELECT button to indicate “ AC ” on the display.

6. Remove power from the circuit under test, then open up the circuit at the point where you wish to measure current.

7. Touch the black test probe tip to the neutral side of the circuit.

Touch the red test probe tip to the “hot” side of the circuit.

8. Apply power to the circuit.

9. Read the current in the display.

RESISTANCE MEASUREMENTS

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.

1. Set the function switch to the green

Ω  position.

2. Insert the black test lead banana plug into the negative COM jack.

Insert the red test lead banana plug into the positive

 jack.

3. Press the SELECT button to indicate “



"

 on the display.

4. Touch the test probe tips across the circuit or part under test.

It is best to disconnect one side of the part under test so the rest of the circuit will not interfere with the resistance reading.

5. Read the resistance in the display.

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CONTINUITY CHECK

WARNING: To avoid electric shock, never measure continuity on circuits or wires that have voltage on them.

1. Set the function switch to the green

Ω position.

2. Insert the black lead banana plug into the negative COM jack.

Insert the red test lead banana plug into the positive

 jack.

3. Press the SELECT button to indicate” "and “ Ω” on the display

4. Touch the test probe tips to the circuit or wire you wish to check.

5. If the resistance is less than approximately 150



, the audible signal will sound. If the circuit is open, the display will indicate “ OL ”.

DIODE TEST

1. Set the function switch to the green

Ω position.

2. Insert the black test lead banana plug into the negative

COM jack and the red test lead banana plug into the positive V jack.

3. Press the SELECT button to indicate and V on the display.

4. Touch the test probes to the diode under test. Forward voltage will typically indicate 0.400 to 0.700V. Reverse voltage will indicate “ OL ”. Shorted devices will indicate near

0V and an open device will indicate “ OL ” in both polarities.

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NON-CONTACT TEMPERATURE MEASUREMENTS

1. Set the function switch to the red IR Non-Contact ºC or ºF position.

2. Point the meter at the surface to be measured.

3. If needed, press the red IR Laser Pointer button to locate the exact spot being measured.

4. The area of the surface to be measured must be larger than the spot size as determined by the distance to spot size specification.

5. Read the temperature in the display.

WARNING: Do not directly view or direct the laser pointer at an eye.

Low power visible lasers do not normally present a hazard, but may present some potential for hazard if viewed directly for extended periods of time.

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DISPLAY BACKLIGHT

Press and hold the HOLD key for >1 second to turn on or off the display backlight function.

Note: The HOLD feature will activate when the Backlight is turned on. Press the HOLD key again to exit Hold .

MAX

Press the MAX button to activate the MAX feature in the voltage or current functions. The display will hold the maximum reading and will update only when a reading higher then the currently displayed reading occurs. Press the MAX button again to disable the feature.

HOLD

The hold function freezes the reading in the display. Press the HOLD key momentarily to activate or to exit the HOLD function.

AUTO POWER OFF

The auto off feature will turn the meter off after 15 minutes.

LOW BATTERY INDICATION

The icon will appear in the lower left conner of the display when the battery voltage becomes low. Replace the battery when this appears.

WRONG CONNECTION INDICATION

The icon will appear in the upper right conner of the display and the buzzer will sound whenever the positive test lead is inserted into the 20A or uA/mA input jack and a noncurrent (green, black or red) function is selected. If this occurs, turn the meter off and reinsert the test lead into the proper input jack for the function selected.

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Specifications

Function

DC Voltage

Range

200mV

Resolution

0.1mV

Accuracy



(0.5% reading + 2 digits)

2V

20V

200V

1000V

0.001V

0.01V

0.1V

1V



(0.8% reading + 2 digits)

AC Voltage

2V

20V

200V

750V

0.001V

0.01V

0.1V

1V



(1.0% reading + 3 digits)

50 to 400Hz



(1.0% reading + 4 digits)



(1.5% reading + 4 digits)



(2.0% reading + 6 digits)

400Hz to 1kHz



(2.5% reading + 8 digits)



(3.0% reading + 8 digits)



(3.5% reading + 8 digits)

DC Current 200



A

2000



A

20mA

0.1



A

1



A

0.01mA



(1.5% reading + 3 digits)

200mA

2A

20A

0.1mA

0.001A

0.01A



(2.5% reading + 5 digits)

AC Current 50 to 400Hz 400Hz to 1KHz

200



A

2000



A

20mA

0.1

1





A

A

0.01mA



(1.8% reading + 8 digits)



(3.0% reading + 7 digits)

200mA 0.1mA

2A

20A

0.001A

0.01A



(3.0% reading + 8 digits)



(3.5% reading + 10 digits)

NOTE: Accuracy is stated at 65 o

F to 83 o

F (18 o

C to 28 o

C) and less than 75% RH.

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Function

Resistance

Temp

(IR)

Range

200

2k





20k



200k



2M



20M



-58 to 518



F

-50 to270



C

Resolution

0.1



0.001k



0.01k



0.1k



0.001M



0.01M



1



F

1



C











Accuracy

(0.8% reading + 4 digits)

(0.8% reading + 2 digits)

(1.0% reading + 2 digits)

(3.0% reading + 5 digits)

2.0% reading or

NOTE: Accuracy specifications consist of two elements:



(% reading) – This is the accuracy of the measurement circuit.



(+ digits) – This is the accuracy of the analog to digital converter.



2



C,



4



F

Diode Test

Continuity Check

IR Spectral response

IR Emissivity

IR distance ratio

Input Impedance

AC Response

ACV Bandwidth

Display

Polarity

Overrange indication

Auto Power Off

Measurement Rate

Low Battery Indication

Patent notice

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

Audible signal will sound if the resistance is less than 150



(approx.), test current <0.7mA

6 to 16µm

0.95 fixed

8:1

>7.5MΩ (VDC & VAC)

Average responding

50Hz to 1kHz

2000 count backlit liquid crystal

“OL” is displayed

15 minutes (approximately)

Automatic (no indication for positive); Minus (-) sign for negative

2 times per second, nominal

“ ” is displayed if battery voltage drops below operating voltage

U.S. Patent 7056012

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Maintenance

WARNING: To avoid electrical shock, disconnect the meter from any circuit, remove the test leads from the input terminals, and turn OFF the meter before opening the case. Do not operate the meter with an open case.

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

1.

KEEP THE METER DRY . If it gets wet, wipe it off.

2.

USE AND STORE THE METER IN NORMAL TEMPERATURES.

Temperature extremes can shorten the life of the electronic parts and distort or melt plastic parts.

3.

HANDLE THE METER GENTLY AND CAREFULLY.

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

1.

Remove the Phillips head screw that secures the rear battery door

2.

3.

4.

Open the battery compartment

Replace the 9V battery

Secure the battery compartment

You, as the end user, are legally bound ( Battery ordinance ) to return all used batteries and accumulators; disposal in the household garbage is prohibited!

You can hand over your used batteries / accumulators, gratuitously, at the collection points for our branches in your community or wherever batteries / accumulators are sold!

Disposal

Follow the valid legal stipulations in respect of the disposal of the device at the end of its lifecycle

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

NOTE: : If your meter does not work properly, check the fuses and batteries to make sure that they are still good and that they are properly inserted.

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REPLACING THE FUSES

WARNING: To avoid electrical shock, disconnect the meter from any circuit, remove the test leads from the input terminals, and turn OFF the meter before opening the case. Do not operate the meter with an open case.

1. Disconnect the test leads from the meter.

2. Remove the protective rubber holster.

3. Remove the battery cover (two “B” screws) and the battery.

4. Remove the four “A” screws securing the rear cover.

5. Lift the center circuit board straight up from the connectors to gain access to the fuse holders.

6. Gently remove the old fuse and install the new fuse into the holder.

7. Always use a fuse of the proper size and value (0.5A/250V fast blow for the 400mA range, 20A/250V fast blow for the 20A range).

8. Align the center board with the connectors and gently press into place.

9. Replace and secure the rear cover, battery and battery cover.

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

UL LISTED

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

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