®
51, 52, 53, 54 Series II
Thermometer
Service Manual
PN 1276123
October 1999
© 1999 Fluke Corporation. All rights reserved. Printed in USA
All product names are trademarks of their respective companies.
LIMITED WARRANTY & LIMITATION OF LIABILITY
Each Fluke product is warranted to be free from defects in material and workmanship under normal use and
service. The warranty period is three years and begins on the date of shipment. Parts, product repairs and
services are warranted for 90 days. This warranty extends only to the original buyer or end-user customer of a
Fluke authorized reseller, and does not apply to fuses, disposable batteries or to any product which, in Fluke’s
opinion, has been misused, altered, neglected or damaged by accident or abnormal conditions of operation or
handling. Fluke warrants that software will operate substantially in accordance with its functional specifications
for 90 days and that it has been properly recorded on non-defective media. Fluke does not warrant that
software will be error free or operate without interruption.
Fluke authorized 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 Fluke. Warranty support is available
if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international
price. Fluke reserves the right to invoice Buyer for importation costs of repair/replacement parts when product
purchased in one country is submitted for repair in another country.
Fluke’s warranty obligation is limited, at Fluke’s option, to refund of the purchase price, free of charge repair, or
replacement of a defective product which is returned to a Fluke authorized service center within the warranty
period.
To obtain warranty service, contact your nearest Fluke authorized service center or send the product, with a
description of the difficulty, postage and insurance prepaid (FOB Destination), to the nearest Fluke authorized
service center. Fluke assumes no risk for damage in transit. Following warranty repair, the product will be
returned to Buyer, transportation prepaid (FOB Destination). If Fluke determines that the failure was caused by
misuse, alteration, accident or abnormal condition of operation or handling, Fluke will provide an estimate of
repair costs and obtain authorization before commencing the work. Following repair, the product will be
returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation
charges (FOB Shipping Point).
THIS WARRANTY IS BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR
ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS
OF DATA, WHETHER ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT, TORT,
RELIANCE OR ANY OTHER THEORY.
Since some countries or states 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 provision of this Warranty is held invalid or unenforceable by a court of competent
jurisdiction, such holding will not affect the validity or enforceability of any other provision.
Fluke Corporation
P.O. Box 9090
Everett WA 98206-9090
U.S.A
Fluke Europe B.V.
P.O. Box 1186
5602 B.D.
Eindhoven, The Netherlands
Table of Contents
Title
Introduction .......................................................................................................
Service Centers..................................................................................................
International Symbols........................................................................................
Precautions and Safety Information ..................................................................
General Specifications ..................................................................................
Environmental ...............................................................................................
Electrical .......................................................................................................
Performance Test and Calibration Required Test Equipment ...........................
Performance Tests .............................................................................................
Display Test ..................................................................................................
Keypad Test ..................................................................................................
Wide Range Performance Test Procedure ....................................................
Ice Bath Construction ...............................................................................
Ice Bath Test .............................................................................................
Verification of IR Communications Port (Fluke 53 and 54).........................
Calibration and Offset Adjustment....................................................................
A/D Calibration.............................................................................................
Reference Junction Calibration .....................................................................
Using the Offset to Adjust for Variation Between Thermocouples ..............
Basic Maintenance.............................................................................................
Cleaning the Thermometer............................................................................
Changing the Batteries ..................................................................................
Disassembly and Reassembly............................................................................
Disassembly ..................................................................................................
Reassembly ...................................................................................................
Reinstalling the LCD Assembly ...............................................................
Rebuilding the Main PCA.........................................................................
Reinstalling the Main PCA .......................................................................
Replaceable Parts...............................................................................................
Index
i
Page
1
2
2
2
4
4
4
5
5
5
6
6
6
7
8
9
9
11
11
12
12
12
13
13
14
14
14
15
15
51, 52, 53, 54 Series II
Service Manual
ii
List of Tables
Table
1.
2.
3.
4.
Title
International Electrical Symbols Used in this Manual...........................................
Recommended Test Equipment .............................................................................
Performance Test Values (K-Type Thermocouple)...............................................
Replaceable Parts ...................................................................................................
iii
Page
2
5
8
15
51, 52, 53, 54 Series II
Service Manual
iv
List of Figures
Figure
1.
2.
3.
4.
5.
6.
Title
Display Segments ..................................................................................................
Ice Bath Test Equipment Connections...................................................................
Calibration Connections ........................................................................................
Calibration Button Access .....................................................................................
Battery Access .......................................................................................................
Exploded View (Model 54 is Shown)....................................................................
v
Page
6
7
9
10
13
17
51, 52, 53, 54 Series II
Service Manual
vi
51, 52, 53, 54 Series II
Service Manual
WWarning
To avoid shock or injury, do not perform the performance tests
or calibration procedures described in this manual unless you
are qualified to do so.
Refer to the Safety Information section of this manual before
using the Fluke 51, 52, 53, 54 Series II Thermometers.
Caution
The Fluke 51, 52, 53, 54 Series II Thermometers contain parts
that can be damaged by static discharge.
Follow the standard practices for handling static sensitive
devices.
Introduction
This manual provides the following service information for the 51, 52, 53, and 54 Series
II Thermometers, hereafter referred to as “the thermometer”.
•
Precautions and safety information
•
Specifications
•
Performance tests
•
Calibration and adjustment
•
Basic maintenance
•
Replaceable parts
For complete operating instructions, refer to the 51/52 Series II Users Manual or the 53,
54 Series II Users Manual, located on the 51/54 Series II CD ROM, part number
1276106.
1
51, 52, 53, 54 Series II
Service Manual
Service Centers
To contact Fluke, order parts, or locate a Fluke service center, call one of the following
telephone numbers:
USA: 1-888-99-FLUKE (1-888-993-5853)
Canada: 1-800-36-FLUKE (1-800-363-5853)
Europe: +31 402-678-200
Japan: +81-3-3434-0181
Singapore: +65-738-5655
Anywhere in the world: +1-425-446-5500
Or, visit Fluke’s Web site at www.fluke.com.
International Symbols
Table 1 identifies the international electrical symbols used in this manual.
Table 1. International Electrical Symbols Used in this Manual
B
Low Battery
Important information
Complies with relevant Canadian Standards
Association directives
Complies with European Union
directives
Precautions and Safety Information
Use the thermometer only in the ways specified in the 51/52 Series II Users Manual and
the 53/54 Series II Users Manual. If the thermometer is used in ways not specified, the
thermometer may be damaged.
In this manual, a Warning statement identifies conditions and actions that pose a hazard
to the user; a Caution statement identifies conditions and actions that may damage the
thermometer or the test instruments.
2
Thermometer
Precautions and Safety Information
Safety Information
WWarning
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 low battery indicator (B) appears. The
possibility of false readings can 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.
•
Models 52 and 54: Measurement errors may occur if voltages on the
measurement surfaces result in potentials 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.
Caution
To avoid damaging the thermometer 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 dispose of batteries in fire.
•
Follow local laws or regulations when disposing of batteries.
•
Match the + and − polarities of the batteries with the battery case
markings.
3
51, 52, 53, 54 Series II
Service Manual
Specifications
General Specifications
Weight
Dimensions
(without holster)
280 g (10 oz)
2.8 cm × 7.8 cm × 16.2 cm
(1.1 in × 3 in × 6.4 in)
Battery
Certification
3 AA batteries
P, ) (TÜV pending)
Safety
CSA C22.2 No. 1010.1 1992
EN 61010 Amendments 1, 2
CAT I
OVERVOLTAGE (Installation) CATEGORY I,
Pollution Degree 2 per IEC1010-1*
* 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.
Environmental
Operating Temperature
−10 C to +50 C (+14 F to +122 F)
Storage Temperature
−40 C to +60 C (−40 F to +140 F)
Humidity
Non Condensing (< +10 C) (< +50 F)
o
o
o
o
95% RH (+10 C to +30 C) (+50 F to +86 F)
o
o
o
o
75% RH (+30 C to +40 C) (+86 F to +104 F)
o
o
o
o
45% RH (+40 C to +50 C) (+104 F to +122 F)
(Without Condensation)
o
o
o
o
o
o
o
o
o
o
Electrical
J-type: −210 C to +1200 C (−346 F to +2192 F)
o
o
o
o
K-type: −200 C to +1372 C (−328 F to +2501 F)
o
o
o
o
T-type: −250 C to +400 C (−418 F to +752 F)
o
o
o
o
E-type: −150 C to +1000 C (−238 F to +1832 F)
o
o
o
o
N-type: −200 C to +1300 C (−328 F to +2372 F)
o
o
o
o
R- and S-type: 0 C to +1767 C (+32 F to +3212 F)
o
o
o
0.1 C / F / K < 1000
o
o
o
1.0 C / F / K ≥ 1000
o
o
J-, K-, T-, E-, and N-type: ±[0.05 % of reading + 0.3 C (0.5 F)]
o
o
[below −100 C (−148 F): add 0.15 % of reading for J, K, E, and N;
and 0.45 % of reading for T]
o
o
R- and S-type: ±[0.05 % of reading + 0.4 C (+0.7 F)]
o
o
0.01 % of reading + 0.03 C per C
o
o
o
o
o
o
(0.05 F per F) outside the specified +18 C to +28 C (+64 F to +82 F) range
o
o
[below −100 C (−148 F): add 0.04 % of reading for J-, K-, E-, and N-type;
and 0.08 % of reading for T-type]
o
o
Susceptibility: ± 2 C (± 3.6 F) for 80 MHz to 200 MHz in 1.5 v/m field, for 200 MHz to
1000 MHz in 3 V/m field.
Emissions: Commercial limits per EN50081-1
o
Measurement
Range
Display
Resolution
Measurement
Accuracy
Temperature
Coefficient
Electromagnetic
Compatibility
o
o
o
Maximum
Differential
Common Mode
Voltage
1 V (Maximum voltage difference between T1 and T2)
Temperature
Scale
ITS-90
Applicable
Standards
NIST-175
o
o
o
o
Accuracy is specified for ambient temperatures between +18 C (+64 F) and +28 C (+82 F) for a period of
1 year. The above specifications do not include thermocouple error.
4
Thermometer
Performance Test and Calibration Required Test Equipment
Performance Test and Calibration Required Test Equipment
Refer to Table 2 for a list of test equipment used in the performance test and calibration
procedures.
Table 2. Recommended Test Equipment
Equipment
Required Characteristics
Output Voltage: 0-1V
Accuracy: 0.0125 %
Resolution: 0.1 µV
DC Voltage Calibrator
Recommended Model
Thermocouple connector
K-type Thermocouple wire
Dewar Flask/Cap
For K-type thermocouple
Copper
Standard
1- pint, or larger capacity
Fluke 5700A or equivalent
Fluke 80CK-M
Fluke P/N 779942
Fluke P/N 601747
Omega
Thermos
Mercury Thermometer
(either °C or °F)
0.02 °C Resolution
0.05 °F Resolution
Princo Model ASTM56C
Princo Model ASTM56F
Thermocouple connector
DB9 Adapter Connector
Fluke P/N 804549
IR Adapter
Fluke P/N 690518
®
PC with Microsoft Windows
installed
Performance Tests
Performance tests are recommended for incoming inspection, periodic maintenance, and
for checking the thermometer’s specifications. If the thermometer fails any part of the
performance tests, calibration and/or repair is indicated.
Before performing these tests:
o
o
o
o
1. Allow the thermometer to stabilize to room temperature, +23 C ± 5 C (+73 F ± 9 F).
2. Check the batteries and replace them if necessary.
Display Test
Turn the thermometer on while pressing the h button. All display segments are
displayed until the h button is released. Confirm that all the display segments are
showing as in Figure 1.
5
51, 52, 53, 54 Series II
Service Manual
51
53
54
52
zb03f.eps
Figure 1. Display Segments
Keypad Test
Check that all keypad switches are functional by pressing each key and confirming the
proper response on the display.
Wide Range Performance Test Procedure
This test verifies the instrument specifications. If the instrument fails this test, perform
the calibration procedure. If the unit continues to fail, it should be taken to a Fluke
service center.
Ice Bath Construction
To begin the performance test, first construct an ice bath as follows:
1. Prepare a Dewar Flask by drilling two holes in its cap to accept the Mercury
thermometer and thermocouple wires, or use a standard laboratory cork.
2. Fill the Dewar Flask with shaved or crushed ice made from distilled water.
3. Fill the Dewar Flask with enough distilled water so that the ice turns to slush, but do
not add enough water to float the ice.
Note
As the ice melts, siphon off the excess water and add more ice. Allow
approximately 5 to 10 minutes for the water to drop back to the freezing
point.
6
Thermometer
Performance Tests
4. Replace the Dewar Flask cap or cork, and insert the thermocouple wires and Mercury
thermometer as shown in Figure 2. Insert the Mercury thermometer to the same depth
as the thermocouple wire.
_
Copper wire
_
K-Type Thermocouple wire
Mercury
Thermometer
-
+
-
K-Type
Thermocouple
connector
+
51, 52, 53, or 54
Series II
Thermometer
+
5700A
Calibrator
Ice bath
-
zb04f.eps
Figure 2. Ice Bath Test Equipment Connections
Ice Bath Test
Use the following procedure to test the thermometer. If the thermometer has two inputs,
this test should be conducted on both thermocouple inputs.
1. If not already selected, select K-type thermocouple on the thermometer using the
D, K, N, and E buttons.
2. Connect the equipment as shown in Figure 2. Allow the setup to thermally stabilize at
least 5 minutes after inserting the thermocouple into the thermometer.
3. Verify that the ice bath temperature reads 0.0 C ± 0.06 C on the Mercury
thermometer.
o
o
4. Short (or apply 0 mV) to the copper wires at the Calibrator.
5. Verify the thermometer reads 0.0 oC ± 0.3 oC.
6. If this test fails, reposition the thermocouple wires and Mercury thermometer to the
same depth in the ice bath, and repeat steps 3-5. If the test continues to fail, perform
the calibration procedure, located after this procedure.
7. Remove the short applied in step 4.
8. Using Table 3, steps 2-5, obtain an output from the Calibrator equal to the values in
the “Input Voltage (mV DC)” column, and verify the thermometer reads within the
limits specified. If any step fails, perform the calibration procedure located later in
this section.
9. Disconnect the thermocouple from the input terminals. This completes the ice bath
test.
7
51, 52, 53, 54 Series II
Service Manual
Table 3. Performance Test Values (K-Type Thermocouple)
Input
Voltage
Step
Equivalent
Temperature
(mV DC)
Display Reading limits
°C
°F
1
0.0000
0.0 °C
32.0 °F
-0.3 to 0.3
31.5 to 32.5
2
0.9193
23.0 °C
73.4 °F
22.7 to 23.3
72.9 to 73.9
3
-5.7297
-190.0 °C
-310.0 °F
-189.3 to -190.7
-308.9 to -311.1
4
40.8853
990.0 °C
1814 °F
989.2 to 990.8
1813 to 1815
5
48.8382
1200 °C
2192 °F
1199 to 1201
2190 to 2194
Verification of IR Communications Port (Fluke 53 and 54)
This section explains how to verify the operation of the IR Communications Port (IR
port). Perform the following procedure using a PC and HyperTerminal. The IR port can
also be verified using Flukeview software.
To set up a HyperTerminal file, follow these steps:
1. Connect the IR adapter cable to the DB9 Adapter connector. Connect the other end of
the DB9 Adapter to a COM port of the PC.
2. Place the Fluke 53 or 54 in front of the IR adapter.
3. Open up a HyperTerminal session. Select Start button, Programs, Accessories,
HyperTerminal.
4. Open up a New Connection with a name like “Fluke 54 IR Test”.
5. When the Connect To box appears, select the COM1 or COM2 (the port that the IR
adapter cable is plugged into).
6. Select Port Settings: 9600 baud rate, 8 data bits, no parity, 1 stop bit, and no flow
control.
7. Under File, select properties. Verify that the correct port is selected. Click on
Configure. Verify that port settings are correct (the baud rate may need to be
changed to 9600).
8. Select the Settings tab then click on ASCII Setup. Check the following boxes:
•
Echo typed characters locally
•
Append line feeds to incoming line ends
•
Wrap lines that exceed terminal width
To open a HyperTerminal file to test the IR port, use the following procedure:
1. Under File, select Save As. Use a file name such as “Fluke 54 IR Test” and then
click on save.
2. Click on the phone disconnect icon.
3. Click on open folder or under File select Open. Double click on Fluke 54 IR Test.
4. Type in "ID" followed by the Enter key (notice the "ID" is capitalized).
5. The display of the thermometer now shows the thermometer name (Fluke 53-II or
Fluke 54-II), and the units operating software version (e.g. Fluke 54-II, V1.01).
8
Thermometer
Calibration and Offset Adjustment
Calibration and Offset Adjustment
Calibration consists of two parts:
1. Calibration of the A/D converter, using the set up shown in Figure 3.
2. Reference junction calibration, using the ice bath test set up shown in Figure 2.
A/D Calibration
To calibrate the A/D portion of the thermometer, follow these steps:
1. Connect the calibrator to the T1 input of the thermometer using copper (nonthermocouple) wire and a copper thermocouple connector. Refer to Figure 3 for
proper equipment connections.
_
2. Turn the thermometer on, with a small, blunt probe, press the calibration button
located on the back and in the center of the thermometer. Refer to Figure 4.
-
Copper
wire
5700A
Calibrator
Copper
Thermocouple
connector
+
51, 52, 53, or 54
Series II
Thermometer
+
-
zb06f.eps
Figure 3. Calibration Connections
9
51, 52, 53, 54 Series II
Service Manual
Calibration
button access
zb02f.eps
Figure 4. Calibration Button Access
3. The menu on the display changes to “CAL A-d”.
Note
Within CAL are four menu options that may be accessed by pressing E:
•
CAL A-d prompts the operator for the A/D calibration inputs in mV dc.
•
CAL rEF allows the operator to calibrate the reference junction at a
known temperature.
•
CAL donE saves the new calibration constants in memory.
•
CAL Abrt ignores calibration changes (turning the thermometer off
while in CAL will also ignore calibration changes).
4. Press K or N to select different menu options.
5. With CAL A-d selected, press E. The thermometer prompts “80”. Set the
calibrator to +80.000 mV and allow the output to stabilize.
Note
For steps 6 and 8, keep hand and body motion to a minimum while the
thermometer takes A/D readings.
6. Press E. Wait while it takes A/D readings.
7. When the thermometer prompts for “-8”, set the Calibrator to -8.0000 mV. Allow the
output to stabilize.
8. Press E on the thermometer and wait while it takes A/D readings. The
thermometer now shows the measured value in the bottom portion of the display.
Millivolts appears on the left side and microvolts appears on the right side.
9. If the measurement is from –7 995.0 to –8 005.0, press E and the meter will
return to the calibration menu and display CAL rEF. If the measurement is outside –
7995.0 to –8005.0, press E once to return to the calibration menu. Using
K or N, select CAL A-d and try the A/D calibration procedure a second time
starting at step 5.
10. Using K or N, select “CAL donE”, then press E to store the calibration in
memory.
10
Thermometer
Calibration and Offset Adjustment
11. To ignore the calibration changes, use K or N, and select “CAL Abrt” and press
E.
12. Proceed to Reference Junction Calibration.
Reference Junction Calibration
Note
This procedure is described using an ice bath and a K-type thermocouple.
It can be performed in °C, °F, or K with any thermocouple and a known,
accurate temperature between 0 °C (+32 °F) and +50 °C (+122 °F).
Note
It is important that the temperature of the thermocouple and the internal
temperature of the thermometer (the reference junction) have stabilized.
To calibrate the reference junction, follow these steps:
1. Prepare an ice bath (described earlier in this section).
2. Referring to Figure 2, connect the equipment to T1 using K-type thermocouple wire
and a K-type thermocouple connector. Allow the setup to thermally stabilize at least
5 minutes after inserting the thermocouple connector into the thermometer.
3. Turn the thermometer on and select the thermocouple type using the D, K, N,
and Ebuttons.
4. Enter calibration mode (refer to the “A/D Calibration” section, step 2).
5. Using K or N, select CAL rEF and press E.
6. Press K or N until the upper display matches the known temperature.
Note
Once adjusted, do not change units (°C, °F, or K) until the thermometer is
in measurement mode.
7. Press the E button.
8. “CAL donE”appears then press E to store the calibration in memory.
9. To ignore the calibration changes, use the K or N, and select “CAL Abrt” and
press E.
Using the Offset to Adjust for Variation Between Thermocouples
Use the offset option in the thermometer SETUP mode to adjust the thermometer's
readings for errors of a specific thermocouple. Use the following procedure:
1. Plug the thermocouple into the thermometer input then allow the setup to thermally
stabilize at least 5 minutes.
2. Place the thermocouple in a known, stable temperature environment (such as an ice
bath, lag 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 bath
temperature. (See "Changing Setup Options” in the 51/52 Series II Users Manual,
and the 53/54 Series II Users Manual.)
11
51, 52, 53, 54 Series II
Service Manual
Basic Maintenance
Basic maintenance required by the thermometer is discussed in this section.
Cleaning the Thermometer
•
Caution
To avoid damaging the thermometer, do not use aromatic
hydrocarbons or chlorinated solvents for cleaning. These
solutions react with the plastics used in the thermometer.
•
Do not allow the LCD to get wet.
•
Do not remove any of the lubricant from the battery/pca
connection.
Clean the thermometer case with a mild detergent and water.
The pca may be washed with isopropyl alcohol or deionized water and a soft brush. Dry
o
o
the pca with clean dry air at low pressure, then bake it at +50 C (+122 F) for 24 hours.
Changing the Batteries
WWarning
•
Replace the batteries as soon as the low battery indicator (B)
appears. The possibility of false readings increases when
the batteries are low. False readings can lead to personal
injury.
•
To avoid electrical shock, disconnect the thermocouple(s)
before opening the battery door.
•
Caution
Do not attempt to recharge the batteries.
•
Do not dispose of the batteries by placing them in fire.
•
Follow local laws or regulations when disposing of
batteries.
•
Match the positive (+) and negative (-) polarities of the
batteries with the markings located on the case.
To replace the batteries, refer to Figure 5 and use the following procedure:
1. Turn the thermometer off.
2. Loosen the battery compartment door screw and remove the battery door.
3. Replace the three AA batteries. To simplify battery installation, put the new batteries
into the unit positive end first.
4. Replace the battery compartment door and tighten the screw.
12
Thermometer
Disassembly and Reassembly
zb01f.eps
Figure 5. Battery Access
Disassembly and Reassembly
Disassembly and reassembly of the thermometer may be necessary to replace interior
parts. Refer to Figure 6 when disassembling and reassembling the thermometer.
Disassembly
To disassemble the thermometer, follow these steps:
1. Remove the batteries (see “Changing the Batteries” section).
2. Remove the two screws located inside the battery compartment.
•
•
Caution
Before proceeding, make sure that you are grounded to
prevent static discharge, which could damage the
thermometer.
Inside the unit there are parts that can become
contaminated by oils from the skin. These parts should not
be directly handled. When lifting out the elastomeric
connectors and the main switch pad, it is recommended that
tweezers or sterile gloves be used.
3. Remove the two case bottom screws, located at the LCD-end of the unit and separate
the bottom case from the top case.
4. Removing any of the interior components of the unit requires removing the Main
PCA. To remove the Main PCA, place the top case face down and remove the two
screws that attach the Main PCA to the top case. Gently lift the Main PCA out of the
top case. The IR Lens, small Isothermal PCA, backlight, elastomeric connectors, and
the LCD may all lift out attached to the Main PCA.
5. If the Isothermal PCA separates from the Main PCA, the Isothermal PCA, IR Lens,
backlight, elastomeric connectors, and the LCD will still be in the top case. Lift them
out of the top case after the Main PCA is removed.
13
51, 52, 53, 54 Series II
Service Manual
6. The LCD decal is now exposed and may be removed.
7. To remove the main switch pad, first remove the small elastomeric connector at the
top of the switch pad, and then lift out the entire switch pad.
Reassembly
The reassembly procedure is basically the reverse of the disassembly procedure.
However, there are several points in this process that should be explained further.
Note
For reassembly, the thermometer top case should be face down, with the
keypad end of the top case facing the user.
Reinstalling the LCD Assembly
Follow these steps to reinstall the LCD assembly:
1. Install the LCD decal.
2. When putting the LCD back into the top case, make sure the LCD is correctly
aligned. The edge of the LCD with the bubble in it should be facing the left side of
the open, face down top case, and the LCD should be placed into the top case face
down.
3. When reinstalling the backlight, the backlight pins should be on the left side of the
open top case and they should be facing up. Check that the pins are straight. To make
sure that the backlight is centered, line up the bottom left corner of the backlight with
the guide that is molded into the top case. The left corner of the backlight should fit
directly over this guide and the bottom right side of the backlight should also be lined
up with (but not over) a similar guide on the right side of the open top case.
4. Install the two LCD elastomeric connectors.
Rebuilding the Main PCA
When reinstalling the Main PCA, make sure that the Isothermal PCA and the IR Lens are
attached to each other first. To do this, follow these directions:
1. Turn the Main PCA over so that the components are face down.
2. Attach the Isothermal PCA to the Main PCA by inserting the pins into the matching
holes on the Main PCA.
Note
When putting the Isothermal PCA back onto the Main PCA, do not push the
Isothermal PCA all the way down into the contact holes of the Main PCA. If
the Isothermal PCA is kept slightly loose, it makes installation of the IR
Lens easier.
3. Reinstall the IR Lens by taking the Main PCA (with the Isothermal PCA loosely
attached), and with the component side facing down; slide the IR Lens in between the
main board and the Isothermal PCA.
4. Line up the tab on the Isothermal PCA and the notch in the IR Lens and push the two
together. The contacts of the IR Lens should slide under the Isothermal PCA and they
should be making contact with pads on the underside of the Isothermal PCA.
14
Thermometer
Replaceable Parts
5. Push the Isothermal PCA and the Main PCA together so that the Isothermal PCA
pins go deeper into the Main PCA sockets. This holds the IR Lens in place and
allows the Main PCA to be reinstalled into the top case.
Reinstalling the Main PCA
1. While holding the IR Lens to the Main PCA, turn the Main PCA over so that the
components are facing up.
2. Align the screw holes in the Main PCA with those in the top case.
3. Align the backlight pins with the Main PCA sockets.
4. Align the Main PCA holes with the backlight posts.
5. Gently push the Main PCA down into the top case, making sure that the IR Lens goes
into the groove on the LCD-end of the top case. If it does not fit together easily,
check to make sure that everything is properly lined up and try again.
6. Reinsert and tighten the two pca screws.
To complete the thermometer reassembly, screw the bottom case to the top case, reinstall
the batteries and screw the battery compartment shut.
Replaceable Parts
Refer to Table 4 for all replacement part numbers and Figure 6 for part locations. Unless
specified in the “Model Number” column, all parts are for all units. To order replaceable
parts, see the “Service Centers” section of this manual.
Table 4. Replaceable Parts
Item
Number
Qty.
Fluke Part
Number
1
3
376756
BATTERY, PRIMARY, 1.5V, 0-150MA, AA ALKALINE
All
2
4
803582
SCREW , PH, P, CAPT, STL, 4-40, .25
All
Description
Model
Number
BATTERY DOOR:
• SCREW, PH, P, AM THD FORM, STL, 4-14, .312
• DOOR, BATTERY
3
4
1
1
642931
669838
All
All
5
1
669812
669804
669801
669796
CASE, TOP
CASE, TOP
CASE, TOP
CASE, TOP
51
52
53
54
6
1
1541901
ISOTHERMAL PCA (TESTED)
All
7
2
804713
CONNECTOR, ELASTOMERIC, LCD TO PWB, 2.210 L
All
8A-F
1
1541895
BOTTOM CASE ASSEMBLY
All
Bottom Case Assembly contains:
8A
2
666435
•
BATTERY CONTACT, DUAL
All
8B
1
674744
•
BATTERY CONTACT (POS)
All
8C
1
674770
•
BATTERY CONTACT (NEG)
All
8D
1
669819
•
CASE, BOTTOM
All
8E
1
658689
•
KEYPAD, CALIBRATION
All
8F
1
675009
•
SHIELD
All
15
51, 52, 53, 54 Series II
Service Manual
Table 4. Replaceable Parts (cont.)
Item
Number
9A-B
Qty.
Fluke Part
Number
1
1
1541912
1543462
Description
51/53 SERIES II IR LENS KIT
52/54 SERIES II IR LENS KIT
Model
Number
51, 53
52, 54
IR Lens Kit contains:
9A
2
4
__
•
SPRING, ISOTHERMAL
51, 53
52, 54
9B
1
__
•
IR LENS
51, 53
•
IR LENS
52, 54
1
10
1
675017
WINDOW, PROTECTOR
All
11
1
675030
675025
675022
675014
LCD DECAL
LCD DECAL
LCD DECAL
LCD DECAL
51
52
53
54
12
1
674747
BACKLIGHT
All
13
1
1272438
HOLSTER & FLEX STAND ASSEMBLY
All
14
2
643830
SCREW, PH, P, METRIC PT, STL, K35, 14MM
All
15
1
669793
669788
669785
669777
KEYPAD
KEYPAD
KEYPAD
KEYPAD
51
52
53
54
16
1
804705
CONNECTOR, ELASTOMERIC, SWITCH TO PWB, 1.200 L
All
17
1
800836
LCD, MULTIPLEXED
All
Not shown
1
1276106
CD ROM, CD ROM FLUKE 50 SERIES II
All
CD ROM contains:
16
•
51/52 Series II Users Manual (16 Languages)
•
53/54 Series II Users Manual (16 Languages)
Not shown
1
1276114
FLUKE 51-54 SERIES II PRODUCT OVERVIEW
All
Not shown
1
2
773135
THERMOCOUPLE ASSY, T/C ASSY, K-TYPE, BEADED, MOLDEDPLUG
51, 53
52, 54
Thermometer
Replaceable Parts
10
5
11
17
9B
9A
6
15
12
8B
7
16
8C
8E
8F
8D
14
8A
2
1
13
3
4
zb07f.eps
Figure 6. Exploded View (Model 54 is Shown)
17
51, 52, 53, 54 Series II
Service Manual
18
Index
—A—
—I—
assembly, 13
ice bath
construction, 6
equipment connections, 7
test, 7
—B—
batteries
access to, 13
changing, 12
—C—
calibration, 9
A/D, 9
A/D connections, 9
button access, 10
CAL Abrt, 10
CAL A-d, 10
CAL donE, 10
CAL rEF, 10
offset, 9
reference junction, 11
variations between thermocouples, 11
caution, 12, 13
CD ROM, 1
—D—
disassembly, 13
display
segments, 6
—E—
electrical symbols, 2
—H—
HyperTerminal, 8
—L—
LCD
reinstalling, 14
—M—
Main PCA
rebuilding, 14
reinstalling, 15
maintenance
basic, 12
batteries, changing, 12
cleaning, 12
—P—
parts
diagram, 17
list of replaceable, 15
performance tests, 5
display test, 5
IR communications port verification, 8
keypad test, 6
test values, k-type thermocouple, 8
wide range, 6
precautions, 2
—R—
reassembly, 14
1
51, 52, 53, 54 Series II
Service Manual
—S—
safety, 2
cautions and warnings, 3
service centers
phone numbers, world wide web address, 2
specifications
electrical, 4
environmental, 4
general, 4
—T—
test equipment
2
performance testing and calibration, 5
—U—
Users Manual
51, 52 Series II, 1
53, 54 Series II, 1
—W—
warnings, 1, 12