TM612A Pocket RTD Thermometer


Wahl TM612A Series Pocket Thermometers is designed to simplify temperature transmitters and probes maintenance and commissioning. Featuring 0.02% Accuracy and measure in RTDs. Resolution is programmable for better reading by user with up to 1mΩ or 1μV.  Rugged IP54 construction is ideal for on-site use as a metrology or control tool. Automatic detection determines if sensor is 2, 3, or 4 wire RTD.

This model includes advanced features, including calibrated sensors (creating a database to design curves for sensors after calibration in relation to the corrections shown on a calibration report), scaling (for correction of probe errors), and data recording (manually, on event, or automatically.)



0.02% of reading

Temperature Coefficient

15 ppm / °C in thermocouples
10 ppm / °C in RTDs

RTD Connection

Lemo 4-pin connector


Graphical LCD with adjustable contrast and backlight.
Display in °C, °F, mV and Ohms

Display Resolution

Three user selectable resolutions, up to 3 decimal places: High, Middle or Low resolution.


English, Spanish, French, German, Italian

Date and Time

Continuously displayed


Freezes the display


Maximum, Average, and Minimum are displayed. Reset function allows re-calculating of the values.


A filter can be applied to avoid fluctuation of the value.


One year warranty covers defects in materials and workmanship


Recording and onscreen analysis


Specifications are at 23°C ± 5°C, between 45% and 75% relative humidity.

Power Supply

Four AA size batteries

Estimated Battery Life

40 hours

Electrical Security


Electromagnetic Capability



6.18 in x 3.35 in x 1.77 in (157mm x 85mm x 45mm)


10.79 ounces (306 grams)

Included Accessories

Protective Boot, Four AA batteries, and wrist strap.

Nominal Operating Conditions

-10°C up to +50°C, Relative Humidity: 20% up to 80% non-condensing

Maximum Operating Conditions

-10°C up to +55°C, Relative Humidity: 10% up to 80% (70% at 55°C)

Maximum Storage Temperature

-30°C up to +60°C (without batteries)

IP Rating

IP 54 according to EN 60529

Communication Port


Storage Capacity

10,000 data with date and time into one or several acquisition bursts