Fluke 51 II Handheld Digital Thermometer

The Fluke 51 II is a professional handheld digital thermometer designed for contact temperature measurement in industrial, laboratory, HVAC and process applications.

It uses interchangeable thermocouple probes to measure the temperature of equipment, pipes, motors, insulation, breakers, electrical connections, liquids and other surfaces or media. The single-input design makes the instrument simple to operate while maintaining high measurement accuracy.

Key Features

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  Single-input digital thermometer
  
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  Supports J, K, T and E-type thermocouples
  
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  Temperature accuracy up to ±(0.05% + 0.3 °C)
  
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  Large backlit display
  
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  Displays temperature in °C, °F or K
  
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  MIN/MAX/AVG temperature recording
  
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  Relative time clock for MIN/MAX/AVG events
  
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  Electronic offset function for thermocouple error compensation
  
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  Typical 1000-hour battery life
  
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  Includes 80PK-1 bead thermocouple probe
  
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  Impact-absorbing holster
  
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  3-year warranty
  

Thermocouple Compatibility

The Fluke 51 II supports several common thermocouple types:

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  J Type: -210 °C to 1200 °C
  
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  K Type: -200 °C to 1372 °C
  
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  T Type: -250 °C to 400 °C
  
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  E Type: -150 °C to 1000 °C
  

The display resolution is 0.1 °C / 0.1 K below 1000 and 1 °C / 1 K at or above 1000.

Accurate Contact Temperature Measurement

The Fluke 51 II provides laboratory-level accuracy of ±(0.05% + 0.3 °C) for J, K, T and E-type thermocouples above -100 °C.

This makes it suitable for checking temperature changes and verifying process or equipment temperatures where reliable contact measurement is required.

MIN/MAX/AVG Temperature Recording

The thermometer records minimum, maximum and average temperatures and provides a relative time reference for these events.

This function helps technicians identify temperature fluctuations and track changes during equipment inspection or process monitoring.

Large Backlit Display

The large backlit display makes measured values easier to read in low-light industrial environments.

Temperature can be displayed in:

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  °C
  
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  °F
  
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  Kelvin (K)
  

Long Battery Life

The Fluke 51 II operates on three AA batteries and provides a typical battery life of approximately 1000 hours. A sleep mode helps conserve battery power during extended field use.

Typical Applications

The Fluke 51 II is suitable for:

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  Industrial temperature measurement
  
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  HVAC maintenance
  
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  Process calibration
  
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  Laboratory temperature testing
  
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  Food safety temperature checks
  
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  Motor temperature measurement
  
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  Pipe temperature measurement
  
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  Electrical equipment inspection
  
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  Breaker and connection temperature checks
  
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  Liquid temperature measurement
  

General Specifications

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  Measurement input: Single input
  
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  Thermocouple types: J, K, T, E
  
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  Accuracy: ±(0.05% + 0.3 °C) above -100 °C
  
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  Display resolution: 0.1 °C / 0.1 K
  
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  Display: Backlit
  
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  Battery: 3 × AA
  
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  Typical battery life: 1000 hours
  
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  Operating temperature: -10 °C to 50 °C
  
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  Storage temperature: -40 °C to 60 °C
  
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  Dimensions: 173 × 86 × 38 mm
  
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  Weight: 400 g
  
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  Temperature scale: ITS-90
  
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  Standard: NIST-175
  

Standard Package

The standard Fluke 51 II includes:

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  Fluke 51 II thermometer
  
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  Impact-absorbing holster
  
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  80PK-1 bead probe thermocouple
  

The Fluke 51 II CAL version additionally includes a traceable certificate of calibration with data from Fluke.

FAQ

What type of thermometer is the Fluke 51 II?

The Fluke 51 II is a single-input handheld digital contact thermometer that uses thermocouple probes.

What thermocouples can the Fluke 51 II measure?

It supports J, K, T and E-type thermocouples.

What is the maximum temperature range?

The maximum range depends on the thermocouple type. With a K-type thermocouple, the specified range is -200 °C to 1372 °C.

Does the Fluke 51 II come with a calibration certificate?

The standard Fluke 51 II includes an 80PK-1 probe but does not include the traceable calibration certificate. The Fluke 51 II CAL version includes a traceable certificate of calibration with data from Fluke.

Is the Fluke 51 II suitable for industrial applications?

Yes. It is designed for applications including industrial temperature measurement, process calibration, HVAC, equipment inspection and maintenance.