Extech Instruments DM220 User Manual

2 DM220-en-US_V3.3 10/20
Introduction
Congratulations on your purchase of the Extech DM220 Pocket Autoranging Multimeter. This meter
measures AC/DC Voltage, AC/DC Current with 200mA/500V resettable fuse, Resistance, Capacitance,
Frequency, Duty Cycle, Diode Test, and Continuity. It features a built-in non-contact AC voltage
detector plus flashlight. Proper use and care of this meter will provide many years of reliable service.
Safety
This symbol adjacent to another symbol, terminal or operating device indicates
that the operator must refer to an explanation in the Operating Instructions to
avoid personal injury or damage to the meter.
This WARNING symbol indicates a potentially hazardous situation, which if not
avoided, could result in death or serious injury.
This symbol indicates that a device is protected throughout by double insulation or
reinforced insulation.
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
V DC or V AC
600V DC/AC
µA AC/DC
200mA 500V fast acting resettable fuse
Resistance, Diode Test, Continuity Test
600V DC/AC
2. USE EXTREME CAUTION when working with voltages greater than 25VAC or 35VDC. These
voltages are considered a shock hazard.
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, continuity or diode tests.
6. ALWAYS turn off the power and disconnect the test leads from the circuit before opening the
cover to replace the batteries.
7. NEVER operate the meter unless the battery cover is in place and fastened securely.
WARNING

Extech Instruments DM220 Specifications

General

Brand	Extech Instruments
Model	DM220
Category	Multimeter
Language	English

Summary

Introduction

Safety Precautions

Product Description

Product Components

Lists and identifies the key parts and features of the DM220 multimeter.

Operating Instructions

AC/DC Voltage Measurements

Step-by-step guide for measuring AC and DC voltage using the multimeter.

AC/DC Current Measurements

Procedures for measuring AC and DC current, including safety warnings.

Resistance Measurements

Instructions for measuring electrical resistance, emphasizing safety.

Continuity Check

Procedure for checking circuit continuity, including audio feedback.

Diode Test

How to perform a diode test and interpret forward/reverse voltage readings.

Capacitance Measurements

Steps to measure capacitance, noting safety requirements for discharging capacitors.

Frequency Measurements

Guide on how to measure frequency (Hz) of a signal.

Duty Cycle Measurements

Procedure for measuring the percentage of duty cycle in a signal.

Non-Contact AC Voltage Detector

Instructions for using the non-contact voltage detection feature.

Maintenance and Features

Flashlight and Auto Power Off

Operation of the built-in flashlight and automatic power-off feature.

Battery Installation

Step-by-step guide for safely installing batteries into the multimeter.

Resettable Fuse

Information on the meter's resettable fuse and its function.

Specifications

Warranty and Support

Two-year Warranty

Details of the manufacturer's two-year limited warranty for the instrument.

Calibration and Repair Services

Information on available calibration and repair services for the product.

Contact Customer Support

Contact information for customer support, calibration, and technical assistance.