ThermoProbe TL3-A Portable Stem Thermometer

The Intrinsically Safe TL3-A thermometer is the latest evolution of ThermoProbe’s industry standard TL series. The TL3-A has been certified to the latest global standards for hazardous locations (Ex).

A large display and easy to hold design makes the TL3-A more convenient for use as a reference in the lab or field. The rugged plastic alloy case and buttons are well suited for use in industrial applications, even with gloves. The TL3-A innovative circuitry provides improved temperature accuracy, response time and battery life.

TL3-A thermometers are intended to be used anywhere a precision glass stem thermometer or other type thermometer is used. Versatile software functions allow easy selection of Celsius or Fahrenheit units and display resolution. Minimum, maximum and average temperatures are automatically stored to memory for later reference. Low battery display, and failure mode indications protect the user from false data. Encoded Calibration is unaffected by temperature, vibration, or battery removal.

Through numerous distributors equipped for calibration and repair, the TL3-A can be supported in many locations throughout the world.

A one-year warranty, protective case and NIST traceable 4-point calibration report are included

Data Sheet



  • Accuracy +/-0.1°F (0.06°C) standard calibration 14°F to 320°F
  • Standard 4 point calibration: 32°F(0°C) , 120°F(49°C), 199°F(93°C) & 300°F(149°C)
  • Resolution: 0.01 Degrees
  • Range: -40°F to 400°F (-40°C to 204°C) Note: Standard calibration does not provide full range accuracy
  • Custom calibration points and ranges available.
  • Temperature time constant: 6 seconds in circulated water bath (time response to 63.2% of temp. step change)
  • Recommended minimum immersion depth: 3″ (7.6cm)

Interface Features:

  • 0.5″ (12.7mm) character LCD
  • Switchable units °C or °F
  • Resolution 0.1 or 0.01
  • Bluetooth Wireless Transmitter
  • Low Battery & Fault indication
  • Continuous operation or Auto Off after 20 minutes.
  • Stores and displays Average, Lowest & Highest readings.
  • Arrows indicating increasing/decreasing temperature.
  • Recommended ambient temperature range: 32°F to 112°F (0°C to 44°C)


  • Stainless steel RTD temperature sensor
    – 100Ω Shock resistant Thin-Film RTD
    – Standard 8″(20cm) or 12″(30cm) lengths
    – Standard 0.25″(6.35mm) diameter with 0.188″ (4.76mm) reduced tip
  • Static-dissipative plastic enclosure with a durable polyester graphics window.
  • Nominal body dimensions: 5 x 1.75 x 0.85″ (13 x 4.4 x 2.2cm)
  • Nominal weight: 4 oz (113 grams)