Calibration of eXacal thermometers


eXacal thermometers are calibrated in our own DAkkS calibration laboratory. The manufacturer-independent laboratory works with the measurand temperature. The DAkkS accreditation ensures that all calibrations are traceable to national and international standards. The calibration service is specialized in the calibration of standards for temperature and uses the most modern temperature fixed points and calibration equipment.




Measurement uncertainty of eXacal thermometers during a DAkkS calibration

The calibration of the eXacal thermometers is carried out at ITS-90 temperature fixed points in the range from argon triple point to silver solidification point with excellent measurement uncertainties. Alternatively, the eXacal thermocouples can be calibrated in the temperature range from -80°C to 1200°C using the comparison method. The measurement uncertainty is calculated from many components. The largest contributions are e.g. for resistance thermometers the reproducibility, ITS-90 characteristic, self-heating and hysteresis.

DAkkS Messunsicherheit Präzisionsthermometer

Fixed point


Measurement uncertainty


Pt100 Typ L

Pt100 Typ M

Pt100 Typ N

Pt100 Typ H

Pt 100 Typ HS

Argon -189,3442 °C 11 mK  
Mercury -38,8344 °C 11 mK 5 mK 6 mK 6mK 6mK
Water 0,01 °C 11 mK 6 mK 6 mK 6mK 6mK
Gallium 29,7646 °C 13 mK 6 mK 6 mK 6mK 6mK
Indium 156,5985 °C 11 mK 9 mK 10 mK 10mK 10mK
Tin 231,928 °C 11 mK 10 mK 11 mK 11mK 11mK
Zinc 419,527 °C 21 mK 21mK 21mK
Aluminium 660,323 °C 25mK 25mK
(150 mK @ 850 °C)

Uncertainty of the eXacal precision thermometers during a DAkkS calibration at the calibration service Klasmeier. The indicated measurement uncertainties correspond to k=2, include an ITS-90 function and are indicated for the respective range.


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