Fluke 53 54 Series II Repair

Fluke’s 53 and 54 Series II thermometers are precision digital instruments designed for industrial and laboratory temperature measurement. These thermometers use external thermocouples to provide accurate, fast, and reliable readings across a wide range of environments, including manufacturing, lab calibration, and HVAC systems. Temperature measurement with thermocouples has long been essential in science and industry, and Fluke has built a reputation for developing rugged, high-accuracy tools to support these applications.

The 53 II features a single thermocouple input, while the 54 II includes dual inputs that allow users to measure two points simultaneously or compare temperature differences. Both models are handheld and designed for professional use, offering laboratory-grade accuracy of ±(0.05% + 0.3 °C) and the ability to log up to 500 temperature readings internally.

Key features of the Fluke 53 and 54 Series II thermometers include a large backlit display, data logging with PC connectivity via FlukeView software, and compatibility with multiple thermocouple types. The devices also feature a rugged, dust and splash-resistant housing, long battery life of up to 1,000 hours, and an easy-access battery compartment for convenience during fieldwork.

While newer Fluke thermometer models have since been introduced, the 53 and 54 Series II remain available through several distributors in the United States and the United Kingdom. The average retail price for these thermometers typically ranges from approximately $400 to $700, depending on the model and included accessories.

The Fluke 53 54 Series II thermometers can be identified by their outer yellow casings and further specified by the brand and model number above the display. Additionally, the device should include one or two thermocouple wires, depending on the model. The size of each model is the same, with dimensions of 6.8 in × 3.4 in × 1.5 in.

The way to distinguish between the 53 and 54 Series II thermometers is mainly by the aforementioned model designation, but another way is to check for the "T1-T2" button in the center of the device. If it has this button, it's a 54 Series II, and if it does not, it's a 53 Series II.

• Power supply: 3 × AA alkaline batteries
• Battery life: Up to 1,000 hours (typical)
• Dimensions: 6.8 in × 3.4 in × 1.5 in (173 mm × 86 mm × 38 mm)
• Weight: ~14 oz (400 g with batteries)
• 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 (without condensation):
  • 0–90%; 0 °C to 35 °C
  • 0% to 70%; 0 °C to 50 °C

• Display update rate: 1 reading per second
• Data logging capacity: Up to 500 readings (stored internally)
• Data transfer: Infrared (IR) port for PC interface (FlukeView® Forms software)
• Temperature accuracy
  • Above -100 °C
    • J, K, T, E, and N-type: ±[0.05% + 0.3 °C]
    • R and S-type: ±[0.05% + 0.4 °C]
  • Below -100 °C
    • J, K, E, and N-types: ±[0.20% + 0.3 °C]
    • T-type: ±[0.50% + 0.3 °C]

• Overvoltage category: CSA C22.2 No. 1010.1 1992; EN 61010 Amendments 1,2
• Agency approvals: CE, CSA, TÜV (pending)

Source: Fluke Product Specifications, Fluke 53 54 Series II User's Manual

• Fluke Corporation Video Demonstration