Sealey MM18 - User Manual

1.1. PERSONAL PRECAUTIONS
 When using this multimeter, please observe all normal safety rules concerning:
Protection against the dangers of electrical current.
Protection of the meter against misuse.
 Full compliance with safety standards can only be guaranteed if used with the test leads supplied. If necessary, they must
be replaced with genuine Sealey leads with the same electrical ratings. Failure to do so will invalidate the warranty.
 DO NOT use leads if damaged or if the wires are bared in any way.
1.2. GENERAL SAFETY INSTRUCTIONS
 Familiarise yourself with the application and limitations of the multimeter as well as the potential hazards.
IF IN ANY DOUBT CONSULT A QUALIFIED ELECTRICIAN.
 USE EXTREME CAUTION when working with high voltages.
 DO NOT use the meter if it is damaged. Before you use it inspect the case. Pay particular attention to the insulation
surrounding the connectors.
 Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity. Replace damaged test
leads before you use the meter.
 DO NOT use the meter if it operates abnormally. Protection may be impaired. When in doubt have the meter inspected by
your Sealey Authorised Dealer.
 DO NOT operate the meter where explosive gas, vapour or dust is present.
 DO NOT apply more than the rated voltage, as marked on the meter, between the probes or between any probe and earth
ground.
 Before use verify the meter's operation by measuring a known voltage.
 When measuring current, turn off circuit power before connecting the meter in the circuit. Remember to place the meter in
series with the circuit.
 WARNING Use caution when working with voltage above 30V ac rms, 42V peak, or 60V dc. Such voltages pose a shock
hazard.
 When using the probes keep your fingers behind the finger guards.
 When making connections, connect the black test lead before you connect the red test lead. When you disconnect the test
leads, disconnect the red one first.
 Remove the test leads from the circuit under test before you open the back cover.
 DO NOT operate the meter with the back cover removed or loosened.
 To avoid false readings, which could lead to possible electric shock or personal injury, replace the button cells as soon as
the low battery indicator ( ) appears.
 DO NOT touch any naked conductor with your hand or skin, to avoid electric shock, DO NOT ground yourself whilst
using the meter.
 When a probe is connected to a dangerous live potential, it must be noted that this potential can occur at the other probe.
 NOTE CAT II measurement category is for measurements performed on circuits directly connected to low voltage
installations. (Examples are measurements on household appliances, portable tools and similar equipment.) DO NOT use
the meter for measurements within Measurement Categories III and IV.
 Disconnect circuit power and discharge all capacitors before testing resistance, diode or continuity.
 Use the proper function for your measurements.
 Before measuring current, check the meter's fuse and turn off power to the circuit before connecting the meter to the
circuit.
 Before moving the function switch or rotating the range switch, disconnect the test leads from the circuit under test.
 The user shall ensure that test probes are correctly selected in order to prevent danger. Probes shall be selected
to ensure that adequate barriers guard against inadvertent hand contact with live conductors under test and that
probes have minimal exposed probe tips. Where there is a risk of the probe tip short circuiting with other live
conductors under test, it is recommended that the exposed tip length shall not exceed 4mm.
NOTE:The warnings, cautions and instructions referred to in this manual cannot cover all possible conditions and
situations that may occur. It must be understood that common sense and caution are factors which cannot be
built into this product, but must be applied by the operator.
INSTRUCTIONS FOR:
POCKET MULTIMETER
Model No: MM18
Thank you for purchasing a Sealey product. Manufactured to a high standard this product will, if used according to these instructions and
properly maintained, give you years of trouble free performance.
1. SAFETY INSTRUCTIONS
IMPORTANT:
PLEASE READ THESE INSTRUCTIONS CAREFULLY. NOTE THE SAFE OPERATIONAL REQUIREMENTS, WARNINGS & CAUTIONS. USE THE
PRODUCT CORRECTLY AND WITH CARE FOR THE PURPOSE FOR WHICH IT IS INTENDED. FAILURE TO DO SO MAY CAUSE DAMAGE AND/OR PERSONAL
INJURY AND WILL INVALIDATE THE WARRANTY. PLEASE KEEP THESE INSTRUCTIONS SAFE FOR FUTURE USE.
Original Language Version
MM18 Issue No:2(I)-09/09/14
© Jack Sealey Limited
1.3. ELECTRICAL SYMBOLS
Alternating Current.
Direct Current.
Both direct and alternating current.
Caution risk of danger refer to operating manual
before use.
Caution risk of electric shock.
Earth (ground) terminal.
Fuse.
The equipment is protected throughout by double
insulation or reinforced insulation.

Summary

Safety Instructions

Personal Precautions

General safety rules for using the multimeter, including protection against electrical hazards.

General Safety Instructions

Detailed safety guidelines, including precautions for use, handling, and avoiding damage.

Electrical Symbols

Explanation of common electrical symbols used in the manual and on the device.

Features

Display Overview

Describes the 3½ digit LCD display with a maximum reading of 1999.

Control Functions

Explains the function and range switches used to select measurement type and range.

Test Probes

Refers to the included test probes for making measurements.

Product Specifications

DC and AC Voltage Specifications

Details ranges, resolution, and accuracy for DC and AC voltage measurements.

DC Current and Resistance Specs

Details specs for DC current measurement and resistance ranges, resolution, and accuracy.

Operating Instructions

Measuring DC Voltage

Steps for measuring DC voltage, including range selection and lead connection.

Measuring AC Voltage

Steps for measuring AC voltage, including range selection and lead connection.

Measuring DC Current

Steps for measuring DC current, including circuit connection and range selection.

Measuring Resistance

Steps for measuring resistance, including range selection and lead connection.

Diode Test

Procedure for testing diodes, including lead connection and interpreting results.

Continuity Test

Procedure for testing continuity, including lead connection and buzzer indication.

Maintenance and Disposal

Maintenance

Instructions for cleaning and maintaining the multimeter.

Battery and Fuse Replacement

Guidance on replacing batteries and fuses, including safety warnings.

Environmental Protection

Information on proper disposal of the product and its components.

Sealey MM18 Specifications

General

Type	Digital
Diode Test	Yes
Continuity Test	Yes
Display	LCD
Display Digits	3.5
Battery	9V
Battery Test	Yes
AC Voltage Range	200V
DC Current Range	10A