T&D DT75 Instruction Manual

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Martindale Electric Company Limited

Metrohm House, Penfold Trading Estate, Imperial Way, Watford WD24 4YY, UK

Tel: [phone] Fax: [phone]

E-mail: [e-mail]
Website: www.martindale-electric.co.uk

© Martindale Electric Company Ltd. 2006

Registered in England No. 3387451. Rev 2 LITDT75

DT75 DIGITAL THERMOMETER

INSTRUCTION
MANUAL

MARTINDALE

ELECTRIC

Trusted by Professionals

Trusted by Professionals



16th Edition Testers



Accessories



Calibration Equipment



Continuity Testers



Electricians’ Kits



Environmental Products



Full Calibration & Repair Service



Fuse Finders



Digital Clamp Meters



Digital Multimeters



Labels



Microwave Leakage Detectors



Motor Maintenance Equipment



Multifunction Testers



Non-trip Loop Testers



Pat Testers & Accessories



Phase Rotation Testers



Proving Units



Socket Testers



Thermometers & Probes



Test Leads



Voltage Indicators



Specialist Metrohm Testers (4 & 5kV)



Specialist Drummond Testers

Check out what else you can get from Martindale:

Martindale Electric Company Limited

Metrohm House, Penfold Trading Estate, Imperial Way, Watford WD24 4YY, UK

Tel: [phone] Fax: [phone]

E-mail: [e-mail]
Website: www.martindale-electric.co.uk

© Martindale Electric Company Ltd. 2006

Registered in England No. 3387451. Rev 2 LITDT75

DT75 DIGITAL THERMOMETER

INSTRUCTION
MANUAL

MARTINDALE

ELECTRIC

Trusted by Professionals

Trusted by Professionals

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/instruct

REMEMBER: SAFETY IS NO ACCIDENT

MEANING OF SYMBOLS:

equipment complies with relevant EU Directives

end of life disposal of this equipment should be in accordance

with relevant EU Directives

For user notes

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/instruct

REMEMBER: SAFETY IS NO ACCIDENT

MEANING OF SYMBOLS:

equipment complies with relevant EU Directives

end of life disposal of this equipment should be in accordance

with relevant EU Directives

For user notes

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
[e-mail].

CONTENTS

1 Introduction 1

1.1 Inspection 1

1.2 Description 1

2 Product Specific Safety Information 3

2.1 Precautions 3

3 Operation 4

3.1 Replacing Battery 4

3.2 How it Works 4

4 Maintenance 6

4.1 Calibration 6

4.2 Cleaning 6

4.3 Repair & Service 6

4.4 Storage Conditions 7

5 Warranty

Specifications

For user notes

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
[e-mail].

CONTENTS

1 Introduction 1

1.1 Inspection 1

1.2 Description 1

2 Product Specific Safety Information 3

2.1 Precautions 3

3 Operation 4

3.1 Replacing Battery 4

3.2 How it Works 4

4 Maintenance 6

4.1 Calibration 6

4.2 Cleaning 6

4.3 Repair & Service 6

4.4 Storage Conditions 7

5 Warranty

Specifications

For user notes

1. INTRODUCTION

This manual contains information and warnings which must be
followed to ensure safe operation of the thermometer.

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.

You should have the following items:

1. Digital thermometer

2. Rubberised holster

3. 9-Volt battery (installed in meter)

4. Instruction manual

5. Two k-type bead thermocouples

1.2 Description

This instrument is a portable, 3½ digit, compact thermometer with
twin sensor inputs for K-Type thermocouples measuring from

-50°C to 1300°C (-58°F to 2000°F). The instrument may be used
in differential mode when thermocouples are connected to both
inputs.

WARNING

READ "SAFETY INFORMATION" BEFORE USING THE METER

Input Protection: 60V DC or 24V rms AC maximum input voltage

on any combination of inputs.

Reading Rate: >2 times per second.
Input Connector: Accepts standard miniature thermocouple

connectors (flat blades spaced 7.9mm, centre to centre).

Environmental
Ambient Operating Range: 0°C to 50 °C (32°F to 122°F)
Storage Temperature: -20°C to 60°C (-4°F to 140°F)
Relative Humidity: 0% to 80% (0°C to 35°C) (32°F to 95°F) 0%

to 70% (35°C to 50°C) (95°F to 122°F)

General
Display: 3½ digit liquid crystal display (LCD) with maximum

reading of 1999.

Battery: Standard 9V battery (PP3 or MN1604)
Battery Life: 200 hours typical (carbon zinc battery).
Dimensions: 147mm (H) x 70mm (W) x 39mm (D)
Weight: 7.6oz (215g)
Supplied Probe: 4ft type “K” thermocouple bead probe (teflon

tape insulated). Maximum insulation temperature 260°C (500°F).
Probe accuracy is ±2.2°C or ±0.75% of reading (whichever is
greater) from 0° to 800°C.

International linearisation follows National Bureau of
Standards / IEC 584 Temperature/Voltage tables for K-Type
thermocouples.

1

1. INTRODUCTION

This manual contains information and warnings which must be
followed to ensure safe operation of the thermometer.

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.

You should have the following items:

1. Digital thermometer

2. Rubberised holster

3. 9-Volt battery (installed in meter)

4. Instruction manual

5. Two k-type bead thermocouples

1.2 Description

This instrument is a portable, 3½ digit, compact thermometer with
twin sensor inputs for K-Type thermocouples measuring from

-50°C to 1300°C (-58°F to 2000°F). The instrument may be used
in differential mode when thermocouples are connected to both
inputs.

WARNING

READ "SAFETY INFORMATION" BEFORE USING THE METER

Input Protection: 60V DC or 24V rms AC maximum input voltage

on any combination of inputs.

Reading Rate: >2 times per second.
Input Connector: Accepts standard miniature thermocouple

connectors (flat blades spaced 7.9mm, centre to centre).

Environmental
Ambient Operating Range: 0°C to 50 °C (32°F to 122°F)
Storage Temperature: -20°C to 60°C (-4°F to 140°F)
Relative Humidity: 0% to 80% (0°C to 35°C) (32°F to 95°F) 0%

to 70% (35°C to 50°C) (95°F to 122°F)

General
Display: 3½ digit liquid crystal display (LCD) with maximum

reading of 1999.

Battery: Standard 9V battery (PP3 or MN1604)
Battery Life: 200 hours typical (carbon zinc battery).
Dimensions: 147mm (H) x 70mm (W) x 39mm (D)
Weight: 7.6oz (215g)
Supplied Probe: 4ft type “K” thermocouple bead probe (teflon

tape insulated). Maximum insulation temperature 260°C (500°F).
Probe accuracy is ±2.2°C or ±0.75% of reading (whichever is
greater) from 0° to 800°C.

International linearisation follows National Bureau of
Standards / IEC 584 Temperature/Voltage tables for K-Type
thermocouples.

1

1. Digital display

2. Rubberised holster

3. ON/OFF button

4. F/C

Press to change between fahrenheit and centigrade

5. MAX

Press to show and store the maximum temperature

6. HOLD

Freezes the reading displayed

7. T1 socket for T1 thermocouple

8. T2 socket for T2 thermocouple

9. Offset adjustment for T1

10. Offset adjustment for T2

11. T1-T2

Displays difference between T1 & T2

1

2

3

4

5

6

9

8

10

7

11

12

14

13

Specification
unit code: DT75
unit name: Digital Thermometer

MARTINDALE

ELECTRIC

Electrical Measurement Range: -50°C to 1300°C (-58°F to

2000°F)

Resolution: Switchable between 1° / 0.1 and °C / °F
Accuracy: For operating temperatures of 18°C to 28°C (64°F to

82°F), for one year, not including thermocouple error:

-50°C to 0°C ±2°C
0°C to 1000°C ±(0.3% rdg + 1°C)
1000°C to 1300°C ±(0.5% rdg + 1°C)

-58°F to 32°F ±4°F
32°F to 2000°F ±(0.3% rdg + 2°F)

Temperature Coefficient: 0.1 times the applicable accuracy
specification per °C from 0 to 18°C and 28 to 50°C (32°F to 64°F
and 82°F to 122°F).

2

1. Digital display

2. Rubberised holster

3. ON/OFF button

4. F/C

Press to change between fahrenheit and centigrade

5. MAX

Press to show and store the maximum temperature

6. HOLD

Freezes the reading displayed

7. T1 socket for T1 thermocouple

8. T2 socket for T2 thermocouple

9. Offset adjustment for T1

10. Offset adjustment for T2

11. T1-T2

Displays difference between T1 & T2

1

2

3

4

5

6

9

8

10

7

11

12

14

13

Specification
unit code: DT75
unit name: Digital Thermometer

MARTINDALE

ELECTRIC

Electrical Measurement Range: -50°C to 1300°C (-58°F to

2000°F)

Resolution: Switchable between 1° / 0.1 and °C / °F
Accuracy: For operating temperatures of 18°C to 28°C (64°F to

82°F), for one year, not including thermocouple error:

-50°C to 0°C ±2°C
0°C to 1000°C ±(0.3% rdg + 1°C)
1000°C to 1300°C ±(0.5% rdg + 1°C)

-58°F to 32°F ±4°F
32°F to 2000°F ±(0.3% rdg + 2°F)

Temperature Coefficient: 0.1 times the applicable accuracy
specification per °C from 0 to 18°C and 28 to 50°C (32°F to 64°F
and 82°F to 122°F).

2

12. T2

Displays temperature measured from socket T2

13. T1

Displays temperature measured from socket T1

14. 0.1°/1°

Press to change resolution/range

2. PRODUCT SPECIFIC SAFETY INFORMATION

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

To avoid electrical shocks, and damage to the instrument,

do not use this instrument when voltages at the

measurement surface exceed 24V AC or 60V DC.

To avoid burns or damage to equipment, do not take

temperature measurements inside microwave ovens.

CAUTION

Repeated flexing can break the thermocouple

leads. To prolong lead life, avoid sharp bends in the

leads, especially near the connector.

!

!

This warranty is the buyer’s sole and exclusive remedy and is in
lieu of all other warranties, expressed or implied, including but not
limited to any implied warranty of merchantability or fitness for a
particular purpose. Martindale shall not be liable for any special,
indirect, incidental or consequential damages or losses, including
loss of data, arising from any cause or theory.

Since some jurisdictions do not allow limitation of the term of an
implied warranty, or exclusion or limitation of incidental or
consequential damages, the limitations and exclusions of this
warranty may not apply to every buyer. If any part of any provision of
this warranty is held invalid or unenforceable by a court or other
decision-maker of competent jurisdiction, such holding will not affect
the validity or enforceability of any other provision or other part of that
provision.

Nothing in this statement reduces your statutory rights.

3

8

12. T2

Displays temperature measured from socket T2

13. T1

Displays temperature measured from socket T1

14. 0.1°/1°

Press to change resolution/range

2. PRODUCT SPECIFIC SAFETY INFORMATION

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

To avoid electrical shocks, and damage to the instrument,

do not use this instrument when voltages at the

measurement surface exceed 24V AC or 60V DC.

To avoid burns or damage to equipment, do not take

temperature measurements inside microwave ovens.

CAUTION

Repeated flexing can break the thermocouple

leads. To prolong lead life, avoid sharp bends in the

leads, especially near the connector.

!

!

This warranty is the buyer’s sole and exclusive remedy and is in
lieu of all other warranties, expressed or implied, including but not
limited to any implied warranty of merchantability or fitness for a
particular purpose. Martindale shall not be liable for any special,
indirect, incidental or consequential damages or losses, including
loss of data, arising from any cause or theory.

Since some jurisdictions do not allow limitation of the term of an
implied warranty, or exclusion or limitation of incidental or
consequential damages, the limitations and exclusions of this
warranty may not apply to every buyer. If any part of any provision of
this warranty is held invalid or unenforceable by a court or other
decision-maker of competent jurisdiction, such holding will not affect
the validity or enforceability of any other provision or other part of that
provision.

Nothing in this statement reduces your statutory rights.

3

8

3. OPERATION

3.1 Replacing the Battery

This meter is powered by a PP3 or MN1604 or equivalent 9-volt
battery. When the meter shows the " " sign the battery must be
replaced to maintain proper operation. Follow the procedure below
to replace the battery.

1. Disconnect the thermocouples and turn the unit off.

2. Using a Phillips screwdriver, remove the three screws securing
the back of the meter.

3. Replace the battery with a new equivalent 9-volt one observing
correct polarity.

NOTE It is essential to transfer the protective insulating

sleeve from the old battery to the new battery.

4. Replace the back cover and re-install the screws.

3.2 How it Works

Selecting °C or °F

The F/C button may be used to change the measurement between
°C and °F. The chosen unit is shown on the display. On power up,
the instrument defaults to the units last selected before power
down.

Single Input Temperature Measurement

To display the temperature from the input selected, press either
the T1 or T2 button, provided that a thermocouple is connected. A
symbol on the display shows the input in use (T1 or T2).

!

4.4 Storage Conditions

The instrument should be kept in warm dry conditions away from
direct sources of heat or sunlight, and in such a manner as to
preserve the working life of the unit. It is strongly advised that the
unit is not kept in a tool box where other tools may damage it.

5. WARRANTY AND LIMITATION OF LIABILITY

This Martindale product is warranted to be free from defects in
material and workmanship under normal use and service. The
warranty period is 2 years and begins on the date of receipt by the
end user. This warranty extends only to the original buyer or end­user customer, and does not apply to fuses, disposable batteries,
test leads or to any product which, in Martindale’s opinion, has
been misused, altered, neglected, contaminated, or damaged by
accident or abnormal conditions of operation, handling or storage.

Martindale authorised resellers shall extend this warranty on new
and unused products to end-user customers only but have no
authority to extend a greater or different warranty on behalf of
Martindale.

Martindale's warranty obligation is limited, at Martindale's option, to
refund of the purchase price, free of charge repair, or replacement of a
defective product which is returned to Martindale within the warranty
period.

4

7

3. OPERATION

3.1 Replacing the Battery

This meter is powered by a PP3 or MN1604 or equivalent 9-volt
battery. When the meter shows the " " sign the battery must be
replaced to maintain proper operation. Follow the procedure below
to replace the battery.

1. Disconnect the thermocouples and turn the unit off.

2. Using a Phillips screwdriver, remove the three screws securing
the back of the meter.

3. Replace the battery with a new equivalent 9-volt one observing
correct polarity.

NOTE It is essential to transfer the protective insulating

sleeve from the old battery to the new battery.

4. Replace the back cover and re-install the screws.

3.2 How it Works

Selecting °C or °F

The F/C button may be used to change the measurement between
°C and °F. The chosen unit is shown on the display. On power up,
the instrument defaults to the units last selected before power
down.

Single Input Temperature Measurement

To display the temperature from the input selected, press either
the T1 or T2 button, provided that a thermocouple is connected. A
symbol on the display shows the input in use (T1 or T2).

!

4.4 Storage Conditions

The instrument should be kept in warm dry conditions away from
direct sources of heat or sunlight, and in such a manner as to
preserve the working life of the unit. It is strongly advised that the
unit is not kept in a tool box where other tools may damage it.

5. WARRANTY AND LIMITATION OF LIABILITY

This Martindale product is warranted to be free from defects in
material and workmanship under normal use and service. The
warranty period is 2 years and begins on the date of receipt by the
end user. This warranty extends only to the original buyer or end­user customer, and does not apply to fuses, disposable batteries,
test leads or to any product which, in Martindale’s opinion, has
been misused, altered, neglected, contaminated, or damaged by
accident or abnormal conditions of operation, handling or storage.

Martindale authorised resellers shall extend this warranty on new
and unused products to end-user customers only but have no
authority to extend a greater or different warranty on behalf of
Martindale.

Martindale's warranty obligation is limited, at Martindale's option, to
refund of the purchase price, free of charge repair, or replacement of a
defective product which is returned to Martindale within the warranty
period.

4

7

Differential Temperature Measurement T1 or T2

In Difference mode, two temperatures are measured, one at the T1
input and the other at T2. Pressing the T1-T2 button displays the
difference in temperature between the two thermocouples. A T1-T2
symbol appears in the display.

Selecting the Display Resolution

The 0.1°/1° button selects either the low resolution 1°, or the high
resolution 0.1°, display mode.

HOLD Mode

The latest value for the T1, T2 or T1-T2 temperature may be frozen
by pressing the HOLD button; a D-H symbol appears in the display
and all further measurement stops until the HOLD button is
pressed again.

MAX Mode

Pressing the MAX button updates the display with the latest
maximum value for the selected measurement (T1, T2 or T1-T2)
and the MAX symbol is shown in the display. A further press of the
MAX button exits the mode.

The HOLD facility is available while the MAX function is being
used. A D-H symbol will be displayed.

4. MAINTENANCE

4.1 Calibration

To maintain the integrity of measurements made using your

instrument, Martindale Electric recommends that it is returned at

least once a year to an approved Calibration Laboratory for

recalibration and certification.

Martindale Electric is pleased to offer you this service. Please

contact our Service Department for details.

E: [e-mail]

T: 01923 650660

4.2 Cleaning

The unit may be cleaned using a soft dry cloth. Do not use
moisture, abrasives, solvents, or detergents, which can be
conductive.

4.3 Repair & Service

There are no user serviceable parts in this unit other than those
that may be described in section 3. Return to Martindale Electric if
faulty. Our service department will quote promptly to repair any
fault that occurs outside the guarantee period.

Before the unit is returned, please ensure that you have checked the:

- battery

- thermocouples

5 6

Differential Temperature Measurement T1 or T2

In Difference mode, two temperatures are measured, one at the T1
input and the other at T2. Pressing the T1-T2 button displays the
difference in temperature between the two thermocouples. A T1-T2
symbol appears in the display.

Selecting the Display Resolution

The 0.1°/1° button selects either the low resolution 1°, or the high
resolution 0.1°, display mode.

HOLD Mode

The latest value for the T1, T2 or T1-T2 temperature may be frozen
by pressing the HOLD button; a D-H symbol appears in the display
and all further measurement stops until the HOLD button is
pressed again.

MAX Mode

Pressing the MAX button updates the display with the latest
maximum value for the selected measurement (T1, T2 or T1-T2)
and the MAX symbol is shown in the display. A further press of the
MAX button exits the mode.

The HOLD facility is available while the MAX function is being
used. A D-H symbol will be displayed.

4. MAINTENANCE

4.1 Calibration

To maintain the integrity of measurements made using your

instrument, Martindale Electric recommends that it is returned at

least once a year to an approved Calibration Laboratory for

recalibration and certification.

Martindale Electric is pleased to offer you this service. Please

contact our Service Department for details.

E: [e-mail]

T: 01923 650660

4.2 Cleaning

The unit may be cleaned using a soft dry cloth. Do not use
moisture, abrasives, solvents, or detergents, which can be
conductive.

4.3 Repair & Service

There are no user serviceable parts in this unit other than those
that may be described in section 3. Return to Martindale Electric if
faulty. Our service department will quote promptly to repair any
fault that occurs outside the guarantee period.

Before the unit is returned, please ensure that you have checked the:

- battery

- thermocouples

5 6