Fluke 51-II Single-Channel Contact Thermometer 51-54 Series II Service Manual
Summary
Maintain peak operational accuracy with this comprehensive Service Manual for the Fluke 51–54 Series II Thermometers. Designed specifically for professional service technicians and field engineers, this guide provides exhaustive instructions on maintenance and repair. It covers foundational knowledge—from electrical schematics to performance testing procedures (keypad/display)—and detailed workflows for advanced calibration, safe disassembly, and component replacement. Essential reading for maintaining reliable temperature measurement integrity.
Page 1 Text Content
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.
Page Summary Contents For Fluke 51-II Single-Channel Contact Thermometer 51-54 Series II Service Manual
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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...
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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 ...
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Table of Contents Title Page Introduction Service Centers.................................................................................................. International Symbols..........................
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51, 52, 53, 54 Series II Service Manual
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List of Tables Table Title Page 1. International Electrical Symbols Used in this Manual........................................... 2. Recommended Test Equipment 3. Performance Test Values (K-Type Ther...
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51, 52, 53, 54 Series II Service Manual
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List of Figures Figure Title Page 1. Display Segments 2. Ice Bath Test Equipment Connections................................................................... 3. Calibration Connections 4. Calibratio...
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51, 52, 53, 54 Series II Service Manual
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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. Re...
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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 (1-888-993-585...
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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 n...
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51, 52, 53, 54 Series II Service Manual Specifications General Specifications Weight 280 g (10 oz) Dimensions 2.8 cm × 7.8 cm × 16.2 cm (without holster) (1.1 in × 3 in × 6.4 in) Battery 3 AA batterie...
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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...
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51, 52, 53, 54 Series II Service Manual 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 di...
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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 a...
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51, 52, 53, 54 Series II Service Manual Table 3. Performance Test Values (K-Type Thermocouple) Input Voltage Equivalent Display Reading limits Step (m V DC) Temperature 0.0000 0.0 °C 32.0 °F -0.3 to 0...
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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...
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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”. Within CAL are four menu options that m...
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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 Ca...
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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 thermomet...
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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 ...
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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,...
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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 M...
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51, 52, 53, 54 Series II Service Manual Table 4. Replaceable Parts (cont.) Item Fluke Part Model Number Qty. Number Description Number 9A-B 51/53 SERIES II IR LENS KIT 51, 53 52/54 SERIES II IR LENS K...
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Thermometer Replaceable Parts zb07f.eps Figure 6. Exploded View (Model 54 is Shown)
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51, 52, 53, 54 Series II Service Manual
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Index —A— —I— assembly, 13 ice bath construction, 6 equipment connections, 7 test, 7 batteries access to, 13 changing, 12 —L— LCD reinstalling, 14 —C— calibration, 9 A/D connections, 9 Main PCA button...
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51, 52, 53, 54 Series II Service Manual performance testing and calibration, 5 —S— safety, 2 cautions and warnings, 3 —U— service centers Users Manual phone numbers, world wide web address, 2 51, 52 S...
Manual Details
| Brand | Fluke |
|---|---|
| Pages | 28 |
| File Size | 402.87 KB |
| Published | June 05, 2026 |
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Frequently Asked Questions
What is the warranty period for the Fluke product?
The standard warranty period is three years and begins on the date of shipment.
Who can receive warranty support for this device?
Warranty support is available only to the original buyer or end-user customer of a Fluke authorized reseller.
Where must I send the product for warranty service?
Send the product, with a difficulty description and prepaid shipping/insurance, to your nearest Fluke authorized service center.
What type of thermocouple is provided and where can I find replacement parts information?
A K-type beaded, molded thermocouple assembly is listed. Replacement parts are detailed on page 17.