Draper DMM300 Instruction Booklet

300 SERIES

MULTIMETER

41821

IMPORTANT: Please read these instructions carefully to ensure the safe and effective use of this product and save
these instructions for future reference. This manual has been compiled by Draper Tools and is an integrated part of the
product with which it is enclosed and should be kept with it for future references.

This manual describes the purpose for which the product has been designed and contains all the necessary information
to ensure its correct and safe use. We recommend that this manual is read before any operation or, before performing
any kind of adjustment to the product and prior to any maintenance tasks. By following all the general safety
instructions contained in this manual, it will ensure both product and operator safety, together with longer life of the
product itself.

AlI photographs and drawings in this manual are supplied by Draper Tools to help illustrate the operation of the product.
Whilst every effort has been made to ensure accuracy of information contained in this manual, the Draper Tools policy

of continuous improvement determines the right to make modifications without prior warning.

1. TITLE PAGE

1.1 INTRODUCTION:

USER MANUAL FOR:

SERIES 300 MULTIMETER

Stock no. 41821.
Part no. DMM300.

1.2 REVISIONS:

Date first published March 2017
Date second published June 2017

As our user manuals are continually updated, users should make sure that they use the
very latest version.

Downloads are available from: http://www.drapertools.com/manuals

DRAPER TOOLS LIMITED WEBSITE: drapertools.com
HURSLEY ROAD PRODUCT HELPLINE: [phone]
CHANDLER’S FORD GENERAL FAX: [phone]
EASTLEIGH
HAMPSHIRE
SO53 1YF
UK

1.3 UNDERSTANDING THIS MANUALS SAFETY CONTENT:

WARNING! Information that draws attention to the risk of injury or death.
CAUTION! Information that draws attention to the risk of damage to the product or

surroundings.

1.4 COPYRIGHT © NOTICE:

Copyright © Draper Tools Limited.
Permission is granted to reproduce this publication for personal & educational use only.
Commercial copying, redistribution, hiring or lending is prohibited.
No part of this publication may be stored in a retrieval system or transmitted in any other
form or means without written permission from Draper Tools Limited.

In all cases this copyright notice must remain intact.

2. CONTENTS

2.1 CONTENTS
Page content

1 TITLE PAGE

1.1 INTRODUCTION ................................................................................................2

1.2 REVISION HISTORY..........................................................................................2

1.3 UNDERSTANDING THIS MANUAL ...................................................................2

1.4 COPYRIGHT NOTICE........................................................................................2

2 CONTENTS

2.1 CONTENTS........................................................................................................3

3 GUARANTEE

3.1 GUARANTEE......................................................................................................4

4 INTRODUCTION

4.1 GENERAL SPECIFICATIONS.........................................................................5-7

4.2 HANDLING & STORAGE....................................................................................8

5 HEALTH & SAFETY INFORMATION

5.1 SAFETY PRECAUTIONS...................................................................................9

6 IDENTIFICATION........................................................................................................... 10

7 UNPACKING & CHECKING

7.1 PACKAGING.....................................................................................................11

7.2 WHAT´S IN THE BOX?.....................................................................................11

8 OPERATING INSTRUCTIONS

8.1 DATA HOLD......................................................................................................12

8.2 MAXIMUM VALUE HOLD.................................................................................12

8.3 FUNCTION TRANSFORM................................................................................12

8.4 BACK LIGHT.....................................................................................................12

8.5 AUTO WARNING..............................................................................................12

8.6 AUTO POWER OFF .........................................................................................12

8.7 DC VOLTAGE...................................................................................................13

8.8 AC VOLTAGE ..................................................................................................13

8.9 DC CURRENT ..................................................................................................13

8.10 AC CURRENT ..................................................................................................13

8.11 RESISTANCE (Ω).............................................................................................14

8.12 MEASURING ENGINE DWELL........................................................................14

8.13 MEASURING REV............................................................................................14

8.14 TESTING DIODE..............................................................................................14

8.15 CONTINUITY TEST..........................................................................................14

9 MAINTENANCE

9.1 MAINTENANCE................................................................................................15

10 EXPLANATION OF SYMBOLS

10.1 FUNCTION KEYS EXPLAINED........................................................................16

10.2 EXPLANATION OF SYMBOLS......................................................................... 17

11 DISPOSAL

11.1 DISPOSAL ....................................................................................................... 18

DECLARATION OF CONFORMITY............................................................................ ENCLOSED

.............................................................................. Page

318

3. GUARANTEE

3.1 GUARANTEE

Draper tools have been carefully tested and inspected before shipment and are guaranteed to
be free from defective materials and workmanship.
Should the tool develop a fault, please return the complete tool to your nearest distributor
or contact Draper Tools Limited, Chandler's Ford, Eastleigh, Hampshire, SO53 1YF.
England.
Telephone Sales Desk: [phone] or Product Helpline [phone].
A proof of purchase must be provided with the tool.
If upon inspection it is found that the fault occurring is due to defective materials or
workmanship, repairs will be carried out free of charge. This guarantee period covering
parts/labour is 12 months from the date of purchase except where tools are hired out when
the guarantee period is 90 days from the date of purchase. This guarantee does not apply
to normal wear and tear, nor does it cover any damage caused by misuse, careless or
unsafe handling, alterations, accidents, or repairs attempted or made by any personnel
other than the authorised Draper warranty repair agent.
Note: If the tool is found not to be within the terms of warranty, repairs and carriage
charges will be quoted and made accordingly.
This guarantee applies in lieu of any other guarantee expressed or implied and variations
of its terms are not authorised.
Your Draper guarantee is not effective unless you can produce upon request a dated
receipt or invoice to verify your proof of purchase within the guarantee period.
Please note that this guarantee is an additional benefit and does not affect your statutory
rights.
Draper Tools Limited.

4. INTRODUCTION

4.1 GENERAL SPECIFICATIONS

Auto ranges and manual range.
Over range protection for all ranges.
Max. Voltage Between Terminals And Earth Ground: 600V DC or AC
Operating Altitude: 2000 meters (7000 ft.)maximum
LCD Display: 19.5mm height character
Max. Show Value: 1999 (3 1/2)
Polarity Indication: ‘-’indicates negative polarity.
Over range Indication: Display 'OL'
Sampling Time: approx. 0.4 second
Unit showing: showing of function and electrical capacity.
Low Battery Indication: “ ” displayed
Auto power off time: 15 min.
Power Supply: 1.5V×2 AAA batteries.

Operating Temperature: 0°C to 40°C (32°F to 104°F)

3.1.15 Storage Temperature: -10°C to 50°C (10°F to 122°F)

3.1.16 Dimension: 150×74×43mm

3.1.17 Weight: approx. 233 g (including battery)

DC Voltage

Range Accuracy Resolution
200mV 0.1mV
2V ± (0.7% of rdg + 3 digits) 0.001V
20V 0.01V
200V 0.1V
600V ± (1.0% of rdg + 3 digits) 1V

Input Impedance: 10M
Overload Protection:
200mV range: 250V DC or AC rms,
2V-600V ranges: 600V DC or AC rms.
Max. Input Voltage: 600V DC

516

4. INTRODUCTION

AC Voltage

Range Accuracy Resolution
200mV 0.1mV
2V ±（0.8% rdg + 5 digits） 0.001V
20V 0.01V
200V 0.1V
600V ±（1.0% rdg + 5 digits） 1V

- Input Impedance: 10M

- Overload Protection:

200mV range: 250V DC or AC rms,
2V-600V ranges: 600V DC or AC rms.

- Frequency Range: 40 to 400Hz

- Max. Input Voltage: 600V rms AC

DC Current

Range Accuracy Resolution
2A 0.001A
10A ±（2.5% rdg + 10 digits） 0.01A

- Overload Protection: 500V/10A FUSE

- Max. Input Current:10A

- Voltage drop: 2A range: 20mV,
10A range: 100mV

AC Current

Range Accuracy Resolution
2A 0.001A
10A ±（3.0% rdg + 10 digits） 0.01A

- Overload Protection: 500V/10A FUSE

- Max. Input Current:10A

- Frequency Range: 40 to 400Hz

- Voltage drop：2A range: 20mV, 10A range: 100mV

4. INTRODUCTION

Resistance

Range Accuracy Resolution
200Ω ±（1.0% rdg + 5 digits） 0.1Ω
2kΩ 0.001kΩ
20kΩ ±（1.0% rdg + 2 digits） 0.01kΩ
200kΩ 0.1kΩ
2MΩ 0.001MΩ
20MΩ ±（1.2% rdg + 5 digits） 0.01MΩ

- Open Circuit Voltage: 0.25V

- Overload Protection: 250V DC or 250V rms AC

Continuity Test

Range Function

Built-in buzzer will sound, if resistance

is lower than 50Ω

- Open circuit voltage: approx. 0.5V

- Overload Protection: 250V DC or 250V rms AC

Engine Dwell

Range Accuracy Resolution
4CYL ±（3º ) 0.1º
6CYL ±（3º ) 0.1º
8CYL ±（3º ) 0.1º

- Overload Protection: 250V DC or rms AC

Engine Rev

Range Accuracy Resolution
4CYL 10RPM
6CYL ±（3.0% rdg + 3 digits） 10RPM
8CYL 10RPM

- Overload Protection: 250V DC or rms AC

Diode

Range Resolution Function

1mV.

- Forward DC Current: approx. 1mA

- Reversed DC Voltage: approx.1.5V

- Overload Protection: 250V DC or rms AC

Display: read approximate forward

voltage of diode.

714

4. INTRODUCTION

4.3 HANDLING & STORAGE

Care must still be taken when handling, dropping this machine will have an effect on the
accuracy.

The environment will have a negative result on its operation if you are not careful. If the air
is damp, components will rust. If the machine is unprotected from dust and debris;
components will become clogged.

5. HEALTH & SAFETY INFORMATION

5.1 SAFETY PRECAUTIONS

This instrument complies with IEC1010 (International Electrotechnical Commission
promulgated safety standards). Design and production using the pollution level 2 safety
requirements.

Warning

To avoid electrical shock or personal injury.

Please read the safety information and “warnings and precautions” before use.

Warning: When measuring voltage above 30V, current above 10ma, AC power with an
inductive load. Use caution not to touch exposed contacts due to the risk of electric shock,
only use approved probes or clamps.

1. Before measuring, check whether the measurement function switch is in the correct
position, check whether the test probe is connected correctly to avoid electric shock.

2. The meter is only to be used in conjunction with the supplied test leads to comply with
safety standards. If the test leads are broken or damaged, replace the test leads of the
same type or the same electrical specifications.

3. Do not use an unapproved fuse to replace the fuse inside the meter. Only replace with
the same model or the same specifications of the fuse. Before changing, remove the
test leads to ensure that there is no signal input.

4. Do not use unapproved batteries to replace the battery inside the meter. Replace only
with the same model or the same electrical specifications of the battery. Before
changing, remove the test leads to ensure that there is no signal input.

5. During electrical measurements, the body must not be directly in contact with the
earth, use insulating materials to keep your body insulated from the earth.

6. Do not store or use in high temperature, high humidity, flammable, explosive and
strong magnetic field environments.

7. Measurements exceeding the limit values of the instrument may damage the
instrument and endanger the safety of the operator.

8. Do not attempt to calibrate or service the instrument.

9. When the LCD shows “ ”, please replace the battery.

10. Do not insert the test leads to be inserted into the current terminals to measure the
voltage!

912

6. IDENTIFICATION

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7. UNPACKING & CHECKING

7.1 PACKAGING

Carefully remove the product from the packaging and examine it for any sign of damage
caused during shipping. Lay the contents out and check them. If any part is damaged or
missing, do not attempt to use the tool and contact the Draper Helpline immediately (see
back page for details).

Retain the packaging material at least during the guarantee period: in case the machine
needs to be returned for repair.

Warning! Some of the packaging materials used may be harmful to children, keep them out
of reach from children.

Disposed of any packaging correctly and according to local regulations.

7.2 WHAT´S IN THE BOX?

As well as the product; there are several parts not fitted or attached to it.

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1110

8. OPERATING INSTRUCTIONS

8.1 DATA HOLD

If you need to hold the data when measuring, press the “HOLD” button, if you press the
button again, the data hold will switch off.

8.2 MAXIMUM VALUE HOLD

If you need data to hold the maxium data when measuring, press the “MAX” button, if you
press put the button again, maximum value hold will switch off.

8.3 FUNCTION TRANSFORM

Press the "FUNC." when measuring the current and voltage, the meter will switch between
DC and AC range. Press "FUNC." When measuring the resistance, diode and continuity,
the meter will switch to the correct measurement function.

8.4 BACK LIGHT

Press “ ” button for two seconds to turn on or turn off the back light, the back light will
stay on for 15 seconds.

Note:

A. Frequent use of the back light will shorten the battery life.

8.5 AUTO WARNING

If the input current is larger than 10A the buzzer will sound.

8.6 AUTO POWER OFF

1. After fifteen minutes without any operation the meter wil automatically switch off.

2. To disable the auto power off function press and hold the “FUNC” key when switching
the meter on.

8. OPERATING INSTRUCTIONS

8.7 DC VOLTAGE

WARNING
Do not use on voltages above 600V DC.

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

2. Set the measurement function range switch to the position.

3. Press the "FUNC." button to enter the DC measurement.

8.8 AC VOLTAGE

WARNING
Do not use on voltages above 600V rms AC.

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

2. Set the measurement function range switch to the position.

3. Press the "FUNC." button to enter the AC measurement.

8.9 DC CURRENT

1. Connect the black test lead to the COM probe socket and the red test lead to the10A
probe socket.

2. Set the measurement fuction range switch to the position.

3. Press the "FUNC." to enter the DC measurement.

Notes:
“ ”10A

500V/10A FUSE

probe socket has the maximum input current of 10A，Overload Protection:

8.10 AC CURRENT

1. Connect the black test lead to the COM probe socket and the red test lead to the 10A
probe socket.

Set the measurement fuction range switch to the position.

2.

3. Press the "FUNC." to enter the AC measurement.

Notes:
“ ”10A

500V/10A FUSE.

probe socket has the maximum input current of 10A，Overload Protection:

138

8. OPERATING INSTRUCTIONS

8.11 RESISTANCE (Ω)

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

Set the measurement fuction range switch to the Ω position.

2.

Notes:
If the resistance is more than 1MΩ, the meter will need several seconds to staberlise its

readings.

8.12 MEASURING ENGINE DWELL

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

Set the measurement fuction range switch to the desired DWELL range position.

2.

8.13 MEASURING REV

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

2. Set the

8.14 TESTING DIODE

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

2. Set the

3. Press the "FUNC." key to switch to test.

measurement fuction range switch to the desired TACH range position.

measurement fuction range switch to " " position.

8.15 CONTINUITY TEST

WARNING
When testing the circuit continuity, be sure that the power to the circuit has been

shut down and all capacitors have been discharged fully.

1. Connect the black test lead to the COM probe socket and the red test lead to the V/Ω
probe socket.

2. Set the measurement fuction range switch to the position.

3. Press the "FUNC." key to switch the continuity test.

Note:
If the circuit is open (or the circuit resistance is higher than 200Ω ), then the figure '0L'

will be displayed.

9. MAINTENANCE

9.1 BATTERY REPLACEMENT

WARNING
Before attempting to open the battery cover of the meter, be sure that test leads

have been disconnected.

156

10. EXPLANATION OF SYMBOLS

10.1 KEYS EXPLANATIONS

• "FUNC" button:

Measuring the current and voltage, the meter will switch between DC and AC range.

or when measuring the resistance, diode and continuity, the meter will switch to the
correct measurement function.

• "HOLD" button:

Used to hold data on screen.

• "MAX" button:

Used to hold maximum value on screen.

• " " button:

This button is used to the switch on/off back light.

10. EXPLANATION OF SYMBOLS

10.2 EXPLANATION OF SYMBOLS

WEEE
Do not dispose of Waste Electrical
& Electronic Equipment in with
domestic rubbish

Attention.

For indoor use.
Do not expose to rain.

Class II construction
(Double insulated)

Conforms to all relevant
safety standards.

Earth

Fuse

Back light

Warning!
Read instruction manuals before
operating and servicing this
equipment.

Diode test

High voltage / current!
Danger.

Voltage AC

Voltage DC

Current DC

Current AC

A

Resistance in Ohms

Continuity test buzzer

DWELL

TACH

MAX

Dwell angle

Tachometer

Max reading hold

Data hold / Screen lock

Auto power off

Low battery display

174

11. DISPOSAL

11.1 DISPOSAL

- At the end of the machine’s working life, or when it can no longer be repaired, ensure

that it is disposed of according to national regulations.

- Contact your local authority for details of collection schemes in your area.

In all circumstances:

• Do not dispose of power tools with domestic waste.

• Do not incinerate.

• Do not abandon in the environment.

• Do not dispose of WEEE*

as unsorted municipal waste.

* Waste Electrical & Electronic Equipment.

NOTES

192

CONTACT US

Draper Tools Limited, Hursley Road,
Chandler's Ford, Eastleigh, Hampshire. SO53 1YF. U.K.

Helpline:
Sales Desk:

[phone]

[phone]
Internet: www.drapertools.com
E-mail: [e-mail]
General Enquiries: [phone]
Service/Warranty Repair Agent:

For aftersales servicing or warranty repairs, please contact the
Draper Tools Helpline for details of an agent in your local area.

YOUR DRAPER STOCKIST

©Published by Draper Tools Limited.

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means,
electronic, mechanical photocopying, recording or otherwise without prior permission in writing from Draper Tools Ltd.

DBMC0217