Fluke 52 II, 51 II User Manual

51 & 52 Series II

Thermometer

Users Manual

®

English
September 1999

© 1999 Fluke Corporation, All rights reserved. Printed in USA
All product names are trademarks of their respective companies.

Limited Warranty & Limitation of Liability

This Fluke product will be free from defects in material and workmanship for 3 years from the date of purchase. This war­ranty does not cover fuses, disposable batteries or damage from accident, neglect, misuse or abnormal conditions of opera-

tion or handling. Resellers are not authorized to extend any other warranty on Fluke’s behalf. To obtain service during the
warranty period, send your defective tester to the nearest Fluke Authorized Service Center with a description of the problem.

THIS WARRANTY IS YOUR ONLY REMEDY. NO OTHER WARRANTIES, SUCH AS FITNESS FOR A PARTICULAR
PURPOSE, ARE EXPRESSED OR IMPLIED. FLUKE IS NOT LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
CONSEQUENTIAL DAMAGES OR LOSSES, ARISING FROM ANY CAUSE OR THEORY. Since some states or countries
do not allow the exclusion or limitation of an implied warranty or of incidental or consequential damages, this limitation of
liability may not apply to you.

10/96

Fluke Corporation
P.O. Box 9090
Everett WA
98206-9090

Fluke Europe B.V.
P.O. Box 1186
5602 B.D. Eindhoven
The Netherlands

Table of Contents

Title Page

Introduction....................................................................................................................1

Contacting Fluke....................................................................................................... 1

Getting Started.............................................................................................................. 4

Components............................................................................................................. 5

Display Elements...................................................................................................... 6

Buttons ..................................................................................................................... 7

Using the Thermometer................................................................................................. 9

Changing Setup Options............................................................................................... 9

Entering or Exiting Setup.......................................................................................... 9

Setup Options........................................................................................................... 9

Changing a Setup Option......................................................................................... 10

Measuring Temperatures.............................................................................................. 11

Connecting a Thermocouple..................................................................................... 11

Displaying Temperatures.......................................................................................... 11

Holding the Displayed Readings............................................................................... 12

Viewing the MIN, MAX, and AVG Readings............................................................. 12

Using the Offset to Adjust for Probe Errors ................................................................... 12

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51 & 52 Series II

Users Manual

Maintenance.................................................................................................................. 13

Replacing the Batteries............................................................................................. 13

Cleaning the Case and Holster................................................................................. 13

Calibration................................................................................................................. 13

Specifications................................................................................................................. 13

Environmental........................................................................................................... 13

General..................................................................................................................... 14

80 PK-1 Thermocouple (supplied with thermometer)................................................ 14

Electrical.................................................................................................................... 14

Replacement Parts and Accessories............................................................................. 15

ii

51 & 52 Series II

Introduction

The Fluke Model 51 and Model 52 Thermometers (“the
thermometer”) are microprocessor-based, digital
thermometers designed to use external J-, K-, T-, and E­type thermocouples (temperature probes) as temperature
sensors.

Use the thermometer only as specified in this manual.
Otherwise, the protection provided by the meter may be
impaired.

Refer to safety information in Table 1 and meter symbols
in Table 2.

Contacting Fluke

To order accessories, receive assistance, or locate the
nearest Fluke distributor or Service Center, call:

1-888-993-5853 in USA & Canada
[phone] in Europe
[phone] in Japan
[phone] in Singapore
[phone] from other countries

Address correspondence to:

Fluke Corporation Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett, WA 98206-9090 5602 BD Eindhoven
USA The Netherlands

Visit us on the World Wide Web at: www.fluke.com

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51 & 52 Series II

Users Manual

Table 1. Safety Information

WWarning

A Warning identifies conditions and actions that pose hazards to the user. To avoid electrical shock or
personal injury, follow these guidelines:

• Before using the thermometer inspect the case. Do not use the thermometer if it appears damaged. Look

for cracks or missing plastic. Pay particular attention to the insulation around the connectors.

• Disconnect the thermocouple(s) from the thermometer before opening the case.

• Replace the batteries as soon as the battery indicator (

lead to personal injury.

• Do not use the thermometer if it operates abnormally. Protection may be impaired. When in doubt, have the

thermometer serviced.

• Do not operate the thermometer around explosive gas, vapor, or dust.

• Do not apply more than the rated voltage, as marked on the thermometer, between the thermocouple(s), or

between any thermocouple and earth ground.

B) appears. The possibility of false readings can

2

Table 1. Safety Information (cont.)

WWarning (cont.)

•

Model 52:

greater than 1 V between the two thermocouples. When potential differences are anticipated between the
thermocouples, use electrically insulated thermocouples.

• When servicing the thermometer, use only specified replacement parts.

• Do not use the thermometer with any part of the case or cover removed.

A Caution identifies conditions and actions that may damage the meter or the equipment under test.

• Use the proper thermocouples, function, and range for your thermometer.

• Do not attempt to recharge the batteries.

• To prevent explosion, do not throw batteries into a fire.

• Follow local laws or regulations when disposing of batteries.

• Match the + and − polarities of the battery with the battery case.

Measurement errors may occur if voltages on the measurement surfaces result in potentials

Caution

51 & 52 Series II

Introduction

3

51 & 52 Series II

Users Manual

Table 2. International Symbols

Refer to the manual for information about this

W

feature.

M

Battery. Complies with relevant Canadian Standards

Getting Started

Everything in this
51 and 52 unless otherwise indicated.

To become familiar with the thermometer, study the
following:

Users Manual

applies both to Models

Complies with European Union directives.

P

Association directives.

• Figure 1 and Table 3 describe the components.

• Figure 2 and Table 4 describe the display.

• Table 5 describes the functions of the buttons.

Then read the following sections.

4

51 & 52 Series II

Getting Started

Components

5

4

3

6

7

Figure 1. Components

1

2

aas01f.eps

Table 3. Components

A Thermocouple T1 input

B

Model 52:

Thermocouple T2 input

C Holster
D Display
E Buttons
F Battery door
G Batteries

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51 & 52 Series II

Users Manual

Display Elements

1

10

9

Figure 2. Display Elements

Table 4. Display Elements

2

3

4

5

A The thermocouple measurement includes an

offset. See "Changing Setup Options."

B The displayed readings do not change.
C A shift function is in progress.

6

D Setup is in progress.

7

E Low battery. Replace the batteries.
F Primary Display.

8

aas02f.eps

Model 51
Model 52:

: T1 reading.

T1, T2, or T1-T2 reading.

G The temperature unit.
H Secondary Display: MAX, MIN, AVG, or offset.

Model 52:

T1or T2 reading.

I The thermocouple type.
J Time Display: The elapsed time.

6

Buttons

A Press A to turn the thermometer on or off.

51 & 52 Series II

Getting Started

Table 5. Buttons

G

(Shift

function)

Press G, M (CANCEL) to stop displaying the minimum, maximum, and average readings in the
secondary display.

Q Press Q to turn the backlight on and off. The backlight turns off after 2 minutes without any button

presses. If the battery is low, the backlight is disabled.

M Press M to step through the maximum, minimum, and average readings. When viewing logged

readings, shows the maximum, minimum, and average of the logged readings.
Press

G, M (CANCEL) to turn off this display.

C Press C to switch between Celsius (

h Press h to freeze or unfreeze the displayed readings.

Press h when turning on the thermometer to test the display. All display elements appear.

T

Model 52:

primary or secondary display.

Press T to toggle showing the T1, T2, and T1-T2 (differential temperature measurement) in the

o

C), Fahrenheit (oF), and Kelvin (K).

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51 & 52 Series II

Users Manual

Table 5. Buttons (cont.)

D Press D to start or exit Setup. (See "Changing Setup Options.")

K Press K to scroll to the Setup option you want to change.

Press K to increase the displayed setting.

N Press N to scroll to the Setup option you want to change.

Press N to decrease the displayed setting.

E Press E to enter a Setup option.

Press E again to store the displayed setting in memory.

8

51 & 52 Series II

Using the Thermometer

Using the Thermometer

1. Plug the thermocouple(s ) into the inpu t connec tor(s ).

2. Press
After 1 second the thermometer displays the first reading.

If no thermocouple is plugged into the selected input or the
thermocouple is "open," the display shows "- - - -"

A to turn on the thermometer.

Changing Setup Options

Use Setup to change the thermocouple type, offset, sleep
mode, and line frequency settings.

The thermometer stores the settings in its memory. Setup
settings reset only when the batteries are removed for
more than 2 minutes.

Entering or Exiting Setup

When the thermometer is in Setup mode, the display
shows s.

• Press

D to start or exit Setup.

Setup Options

Menu

Option

Thermocouple
Type

Offset O T1 or T2 (Model 52)
Sleep Mode SLP on (sleep mode on)

Line Frequency Li ne 50 H (50 Hz)

Item Settings

TYPE J, K, T, or E

or 0FF (sleep mode
off)

or 60 H (60 Hz)

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51 & 52 Series II

Users Manual

Changing a Setup Option

1. Press K or N to scroll to the setup option you
want to change.

2. Press

3. Press

4. Press

E to indicate that you want to change this

setting.

K

or N until the setting you want to use

appears on the display.

E to store the new setting in memory.

Notes
Setup is disabled in MIN MAX mode.
Offset:
The primary display shows the temperature plus

the offset and the secondary display shows the
offset. Remember to reset the offset to 0.0 when
it is no longer needed. The offset automatically
resets to 0.0 when you change the thermocouple
type. Model 52: You can store individual offsets
for T1 and T2.

Sleep mode:
The thermometer enters sleep mode if no button

press occurs for 20 minutes. Pressing any button
wakes the thermometer and returns it to its
previous state. Sleep mode becomes enabled
each time you turn on the thermometer and is
automatically disabled in MIN MAX mode.

Line frequency:
For optimum rejection of line noise, the

thermometer must be set for the local line
frequency.

10

51 & 52 Series II

Measuring Temperatures

Measuring Temperatures

Connecting a Thermocouple

To change the thermocouple type, see “Changing Setup
Options.” The North American ANSI Color Code is:

Type JK ETN
Color Black Yellow Purple Blue Orange

1. Plug a thermocouple into the input connector(s).
(Make sure that the polarity is correct.)

2. Set the thermometer for the correct thermocouple
type.

Displaying Temperatures

1. Press C to select the correct temperature scale.

2. Hold or attach the thermocouple(s) to the
measurement location.

The temperature reading appears in the primary
display.

Model 52:

3.
T1, T2, and T1-T2 readings in the primary or
secondary display.

Press T to toggle between showing the

Notes

The display shows "- - - -" when a thermocouple
is not connected.

0L

The display shows
temperature being measured is outside the
thermocouple’s valid range.

Model 52: If only thermocouple T2 is connected,
the T2 reading appears in the primary display.

(overload) when the

11

51 & 52 Series II

Users Manual

Holding the Displayed Readings

1. Press h to freeze the readings on the display.
The display shows H.

Model 52:

2.
T1-T2 readings in the primary or secondary display.

3. Press

Press T to toggle showing the T1, T2, or

h again to turn off the HOLD function.

Viewing the MIN, MAX, and AVG Readings

1. Press M to step through the maximum (MAX),
minimum (MIN), or the average (AVG) readings.

The elapsed time since entering MIN MAX mode, or
the time at which the minimum or maximum occurred,
appears on the display.

2. Press

G, M (CANCEL) to exit MIN MAX mode.

Using the Offset to Adjust for Probe Errors

Use the offset option in Setup to adjust the thermometer’s
readings to compensate for the errors of a specific
thermocouple.

The allowable adjustment range is ± 5.0 oC or K, and

o

F.

± 9.0

1. Plug the thermocouple into the input connector.

2. Place the thermocouple in a known, stable
temperature environment (such as an ice bath or a
dry well calibrator).

3. Allow the readings to stabilize.

4. In Setup change the offset until the primary display
reading matches the calibration temperature. (See
"Changing Setup Options.")

12

51 & 52 Series II

Maintenance

Maintenance

Replacing the Batteries

Refer to the safety information in Table 1 before replacing
the batteries.

1. Turn off the thermometer if necessary.

2. Loosen the screw and remove the battery door.

3. Replace the three AA batteries.

4. Replace the battery door and tighten the screw.

Cleaning the Case and Holster

Use soap and water or a mild commercial cleaner.
Wipe with a damp sponge or soft rag.

Calibration

To ensure that the thermometer performs to its accuracy
specifications, Fluke recommends that you calibrate the
thermometer annually, starting one year after purchase.

To calibrate the thermometer, contact Fluke for the
Service Center nearest you or follow the calibration
procedure in the service manual listed in "Replacement
Parts and Accessories."

Specifications

Environmental

Operating
Temperature

Storage Temperature −40 oC to +60 oC

Humidity 0 % to 90 %: −10 oC to 35 oC

−10 oC to 50 oC

o

(14

F to 122 oF)

o

(−40

(14
0 % to 70 %: −10 oC to 50 oC

(14

F to +140 oF)

o

F to 95 oF)

o

F to 122 oF)

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51 & 52 Series II

Users Manual

General

Weight 280 g (10 oz)
Dimensions

(without
holster)

Battery 3 AA batteries
Certification P, ) (TÜV pending)
Safety CSA C22.2 No. 1010.1 1992

CAT I OVERVOLTAGE (Installation)

* Refers to the level of Impulse Withstand Voltage protection

provided. Equipment of OVERVOLTAGE CATEGORY I is
equipment for connection to circuits in which measures are
taken to limit the transient over voltages to an appropriate low
level. Example include protect electronic circuits.

2.8 cm × 7.8 cm × 16.2 cm
(1.1 in × 3 in × 6.4 in)

EN 61010 Amendments 1, 2

CATEGORY I, Pollution Degree 2
per IEC1010-1*

80 PK-1 Thermocouple (supplied with thermometer)

Type Type K, Chromel Alumel, bead style
Temperature

Range
Accuracy ± 1.1 oC (± 2.0 oF)

−40 oC to +260 oC
(−40 oF to +500 oF)

Electrical

Measurement
Range

Display
Resolution

J-type: −210 oC to +1200 oC
(−346 oF to + 2192 oF)

K-type: −200 oC to +1372 oC
(−328 oF to +2501 oF)

T-type: −250 oC to +400 oC
(−418 oF to +752 oF)

E-type: −150 oC to +1000 oC
(−238 oF to +1832 oF)

0.1 oC / oF / K < 1000o

1.0 oC / oF / K ≥ 1000o

14

51 & 52 Series II

Replacement Parts and Accessories

Electrical (cont.)

Measurement
Accuracy, T1,
T2, or T1-T2

(Model 52)

Temperature
Coefficient

Maximum
Differential
Common Mode
Voltage

Temperature
Scale

Applicable
Standards

Accuracy is specified for ambient temperatures
between 18

o

year. The above specifications do not include
thermocouple error.

J-, K-, T-, and E-type: ±[0.05 % of
reading + 0.3

[below −100 oC (−148 oF): add 0.15 % of
reading for J-, K-, E-, and N-type; and

0.45 % of reading for T-type]

0.01 % of reading + 0.03 oC per oC
(0.05
specified +18

o

F) range

+82
[below −100

o

C (0.5 oF)]

o

F per oF) outside the

o

C to 28 oC (+64 oF to

o

C (−148 oF): add

0.04 % of reading for J-, K-, E-, and
N-type; and 0.08 % of reading for
T-type]

1 V (Maximum voltage difference
between T1 and T2)

ITS-90

NIST-175

C (64 oF) and 28 oC (82 oF) for a period of 1

Replacement Parts and Accessories

Accessory Part Number

Holster and Flex Stand Assembly 1272438
AA NEDA 15A IEC LR6 batteries 376756
80PK-1 K-Type Bead Thermocouple 773135
CD-ROM 1276106
Service Manual 1276123

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51 & 52 Series II

Users Manual

16