Pt100 Model L Low-Temperature Precision Thermometers

The eXacal precision thermometers are used for precise temperature measurements or as calibration standards.

  • NEW design: gastight handle with inert gas filling
  • Temperature range: -200 °C to 250 °C
  • small measurement uncertainties: 11 mK to 13 mK
  • robust alternative to ITS-90 standard thermometers
  • high stability and good calibration capability
  • low hysteresis and drift due to inert gas

New design: gastight handle with inert gas filling

Due to the new design of the gas-tight handle, the thermometer’s protective tube can be filled with a protective gas. This improves the properties of the thermometer and ensures less drift and hysteresis at the extremely low temperatures down to the argon point (-189 °C).


eXacal thermometers are calibrated in our own DAkkS calibration laboratory. The DAkkS accreditation ensures that all calibrations are traceable to national and international standards.

The calibration of eXacal resistance thermometers is carried out at ITS-90 fixed points. It is also possible to carry out calibrations according to the comparison method in liquid baths and calibration furnaces. The measurement uncertainty is calculated from many components. The largest contributions are reproducibility, ITS-90 function, self-heating and hysteresis.

Measurement Uncertainties

  • Small measurement uncertainties with DAkkS calibration certificate
  • Temperature fixed points from argon triple point -189,3442 °C  to tin freezing point 231.928 °C
  • ITS-90 standard thermometer for comparison calibration
Range Fixed Point Uncertainty
-189,3442 °C Argon 11 mK
-38,8344 °C Mercury 5 mK
0,01 °C Water 5 mK
29,7646 °C Gallium 6 mK
156,5985 °C Indium 9 mK
231,928 °C Tin 10 mK

The given measurement uncertainties correspond to k=2, include an ITS-90 function and are given for the respective range.

Technical data

Model eXacal Pt100L
Temperature range -189,4332 °C to 231,928 °C
Nominal resistance Pt100 (100 Ohm)
typical annual drift 2,5 mk
Connection type Four-wire
Connecting cable temperature resistant – very low EMF stranded wires from own production
Connection Banana plugs or depending on configuration
Sheath material Metal
Thermometer wire silver
Handle ∅ 20 mm x 100 mm (new design: gas tight)
diameter 6 mm
Length 400 mm
Connection cable 2 m
R0 100 Ohm ± 0,05 Ohm
Alpha 0,003850 ± 0,000005
Standard IEC 60751:2008
tolerance 1/10 DIN
length 25 mm
recommended measuring current 1 mA
Self-heating 5 mK to 10 mK
DAkkS Calibration
Fixed point calibration 11 mK to 13 mK
Comparison calibration 15 mK to 25 mK


Questions about the thermometer?