
MM64 MULTIMETER
Thank you for buying one of our products. For safety and full
understanding of its benefits please read this manual before
use. Technical support is available from 01923 441717 and
support@martindale-electric.co.uk.
CONTENTS
1 Introduction 1
1.1 Inspection 1
1.2 Description 1
1.3 Accessories 1
1.3 Battery Installation 1
2 Product Specific Safety Information 2
2.1 Precautions 2
3 Operation 4
3.1 General 4
3.2 Low Battery Indication 4
3.3 Description of Terminals 4
3.4 Description of Press Buttons 4
3.5 Description of LCD Symbols 5
3.6 Max/Min 5
3.7 Backlight 5
3.8 Voltage Measurement 5
3.9 Current Measurement 5
3.10 Resistance Measurement 6
3.11 Capacitance Measurement 6
3.12 Frequency Measurement 6
3.13 Temperature Measurement 7
3.14 Temperature Offset Adjustment 7
3.15 Continuity Testing 7
3.16 Diode Testing 8
4 Maintenance 9
4.1 Battery Replacement 9
4.2 Fuse Replacement 9
4.3 Test Lead Replacement 9
4.4 Calibration 10
4.5 Cleaning 10
4.6 Repair & Service 10
4.7 Storage Conditions 10
5 Warranty 11
Specifications
INSTRUCTION
MANUAL
GENERAL SAFETY INFORMATION: Always read before proceeding.
Warning
These instructions contain both information and warnings that are
necessary for the safe operation and maintenance of this product. It is
recommended that you read the instructions carefully and ensure that the contents
are fully understood. Failure to understand and to comply with the warnings and
instructions can result in serious injury, damage or even death.
In order to avoid the danger of electrical shock, it is important that proper safety
measures are taken when working with voltages exceeding 30V AC RMS, 42V AC
peak or 60V DC.
This product must only be used by a competent person capable of interpreting the
results under the conditions and for the purposes for which it has been
constructed. Particular attention should be paid to the Warnings, Precautions and
Technical Specifications. Always check the unit is in good working order before
use and that there are no signs of damage to it. Do not use if damaged.
Where applicable other safety measures such as use of protective gloves, goggles
etc. should be employed.
Please keep these instructions for future reference. Updated instructions and
product information are available at: www.martindale-electric.co.uk
REMEMBER: SAFETY IS NO ACCIDENT
MEANING OF SYMBOLS:
Equipment complies with relevant EU Directives
Caution - risk of danger & refer to instructions
Caution - risk of electric shock
Equipment protected by double or reinforced insulation (Class II)
End of life disposal of this equipment should be
in accordance with relevant EU Directives
Direct current (DC)
Alternating current (AC)
Earth (ground)
1. INTRODUCTION
1.1 Inspection
Examine the shipping carton for any sign of damage. Inspect the unit
and any accessories for damage. If there is any damage then consult
your distributor immediately.
1.2 Description
The MM64 is a 3½ digit multimeter with the following functions:
AC & DC voltage to 600V
AC & DC current to 200mA
Resistance to 20MΩ
Capacitance to 20mF
Frequency to 40kHz
Temperature to 750°C/1400°F using Type K thermocouple
Continuity with audible indication
Diode testing
Further functions are:
Max/Min indication
Display backlight
Auto power off
1.3 Accessories (included)
TL16 test leads
Type K thermocouple
Spare 0.25A/500V, fast acting ceramic fuse
9V battery (installed)
Instructions
1.4 Battery Installation
Refer to Section 4.1 (Battery Replacement) for the battery installation
instructions for the MM64.
1

2. PRODUCT SPECIFIC SAFETY INFORMATION
Measurement Category III (CAT III) is applicable to test and
measuring equipment connected to the distribution part of the
building’s low-voltage MAINS installation.
Warning
Always test this unit on an appropriate proving device or known
voltage source before and after using it to determine if a
hazardous voltage exists in a circuit to be tested.
Measurement Category IV (CAT IV) is applicable to test and
measuring equipment connected at the source of the building’s lowvoltage MAINS installation.
2.1 Precautions
This product has been designed with your safety in mind, but
please pay attention to the following warnings and cautions before
use.
Warning
Before use check the unit for cracks or any other damage. Make
sure the unit is free from dust, grease and moisture. Also check any
associated leads and accessories for damage. Do not use if
damaged.
Warning
Do not use if the battery/fuse cover is not fitted.
Warning
When this unit is used in combination with test leads, the
measurement category of the combination is the lower
measurement category of either this unit or the test leads used.
Likewise, if test lead accessories such as crocodile clips are also
used, the measurement category will be the lowest measurement
category in that combination.
Warning
When using test leads, always keep your fingers behind the finger
guard on the test lead probe.
Warning
Measuring a voltage that exceeds the specified limits of the unit
may damage the unit and expose the operator to a shock hazard.
Always check the unit’s specified limits before use.
Warning
To avoid electrical shock, and damage to the instrument, do not
use this instrument and the associated temperature probe when
voltages at the measurement surface exceed 30V AC rms or 60V
DC.
Caution
To avoid burns or damage to equipment, do not take temperature
measurements inside microwave ovens.
Caution
Avoid severe mechanical shock or vibration and extreme
temperature.
3. OPERATION
3.1 General
If the multimeter does not measure current the internal fuse (F1)
may have blown (see section 4.2 Fuse Replacement).
If the multimeter does not measure capacitance the internal fuse
(F2) may have blown (see section 4.2 Fuse Replacement).
If the magnitude of a parameter to be measured is unknown, but
known to be within the maximum safe limits of the multimeter, then
manually set the range to maximum. For example, if measuring DC
voltage and the voltage magnitude is unknown, set the range to
600V, then if required reduce the range for a satisfactory reading.
If the multimeter displays OL or -OL then the measurement limits
of the range have been exceeded.
3.2 Low Battery Indication
If the symbol is displayed then the battery needs replacing
(see section 4.1 Battery Replacement).
3.3 Description of Terminals
F Input terminal for capacitance measurements
mA Input terminal for AC & DC current measurements
COM Common terminal for all measurements
VΩ Input terminal for AC & DC voltage, resistance
continuity, diode and frequency measurements
TYPE K Input terminals for Type K thermocouple
3.4 Description of Press Buttons
MAX/MIN Selects maximum/minimum function
Turns on/off the backlight
3.5 Description of LCD Symbols
MAX Maximum indication is selected
MIN Minimum indication is selected
kHz Unit of frequency measurement being displayed
Indicates battery is low
3.6 Max/Min
To select the Max/Min function press the Max/Min button.
Alternate between displaying the maximum and minimum
measured values by pressing the Max/Min button.
To exit the Max/Min function hold down the Max/Min button for 2
seconds.
3.7 Backlight
Press the button to turn on/off the backlight.
The backlight will automatically turn off after approx 4½ minutes.
3.8 Voltage Measurement
Connect the black test lead to the COM terminal and the red test
lead to the VΩ terminal.
Set the rotary switch to either AC V or DC V and the required
range.
Taking all necessary safety precautions connect the test leads to
the circuit being measured and read the measured voltage from
the display.
3.9 Current Measurement
Connect the black test lead to the COM terminal and the red test
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lead to the mA terminal.