Extech Instruments AUT500 User Manual

USER GUIDE

Automotive Multimeter

MODEL AUT500

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Introduction

Thank you for selecting the Extech AUT500 Automotive Multimeter. The AUT500 is an Auto Range
Multimeter that measures AC/DC Voltage, AC/DC Current, Resistance, Capacitance, Frequency,
Diode, Continuity, RPM, Dwell, and Duty Cycle. The AUT500 also measures contact temperature via
supplied Thermocouple probe.

The AUT500 features a rugged design for heavy duty use. This device 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, and Customer
Support.

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

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.

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 any damage or replace the unit 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.

 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".

WARNING

CAUTION

MAX
600V

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 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.

DANGERS

 Engines produce carbon monoxide which is odorless, causes slower reaction time, and can

lead to serious injury. When the engine is operating keep service areas well ventilated or
attach the vehicle exhaust system to the shop exhaust removal system.

 Set the parking brake and block the wheels before testing or repairing the vehicle. It is

especially important to block the wheels on front-wheel drive vehicles; the parking brake does
not hold the drive wheels.

 Wear an eye shield when testing or repairing vehicles.

 Keep the meter away from spark plug and coil wires.

 Exceeding the limits of this meter is dangerous. This will expose you to serious or possibly fatal

injury. Carefully read and understand the cautions and the specification limits of this meter.

 Avoid electrical shock; do not touch the test leads, tips, or the circuit under test.

 Do not try a voltage measurement with the test leads in the 20A or the mA terminal.

 Choose the proper range and function for the measurement. Do not try voltage or current

measurements that may exceed the ratings marked on the Function/Range switch or terminal.

 When measuring current, connect the meter in series with the load.

 Never connect more than one set of test leads to the meter.

 Disconnect the live test lead before disconnecting the common test lead.

 The mA and the 20A terminals are protected by fuses. To avoid possible injury or damage, use

only in circuits limited to 400mA.

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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.

METER SAFETY RULES

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:

Input Protection Limits

Function Maximum Input

Voltage DC or V AC

Ohms, Continuity

Diode, Capacitance, Type K Temperature

Frequency, % Duty, Pulse-ms, Dwell

RPM

600V AC or DC

mA AC/DC 400mA 250V

20A AC/DC 20A AC or DC*

* 20A measurements for 30 seconds maximum

Notes: Resistance (Ohms) cannot be measured if voltage is present. Resistance can only be
measured on a non-powered circuit

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.

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Controls and Jacks

1. LCD display

2. MODE button

3. HOLD button

4. RANGE button

5. PEAK button

6. MAX-MIN button

7. Backlight button

8. Function switch

9. 20A input jack

10. 400mA input jack

11. Positive input jack

12. COM input jack

Note: Tilt stand, test lead holders, and battery compartment are located on rear of unit. Fuses are
accessible by removing the meter’s back cover, instructions provided later in this guide.

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Symbols and Annunciators

•))) Continuity

Diode test

Battery status

n nano (10

-9

) (capacitance)

µ micro (10

-6

) (amps, cap)

m milli (10

-3

) (volts, amps, milli-seconds: ms)

A Amps

k kilo (10

3

) (ohms)

F Farads (capacitance)

M mega (10

6

) (ohms)

 Ohms (resistance, continuity)

Hz Hertz (frequency)

V Volts

% Percent

REL Relative (unused in this model)

AC Alternating current

DC Direct current

MAX Highest reading

MIN Lowest reading

ºF Degrees Fahrenheit

ºC Degrees Centigrade

Pmax Maximum peak

Pmin Minimum peak

RPM Rotations per minute

Trig Positive (+) or Negative (-) Trigger

CYL Cylinder (4, 5, 6, and 8)

Display Hold

x10 Multiply displayed reading by 10

Bargraph

Manual range (top left on LCD)

AUTO Auto range mode

Auto Power OFF icon (middle left on LCD)

Dwell angle icon

H