DAkkS calibration of thermometers at low temperatures
Do you want to calibrate thermometers at extremely low temperatures? But the temperature range of the calibration baths and standardised procedures used is not sufficient for you? Then you’ve come to the right place. We use boiling nitrogen to extend the temperature range.
With the three calibration procedures shown here, you can have thermometers calibrated by us DAkkS in the temperature range from -180 °C to -80 °C and at the fixed temperatures of -189 °C and
-196 °C.
Calibration at low temperatures
Overview of our DAkkS calibration services
Ar
-189 °C
ITS-90 calibration
down to the triple point
of argon
LN2
-196 °C
Thermometer calibration with
liquid nitrogen as reference temperature
-180 °C to -80 °C
Thermometer calibration with
freely selectable calibration points in the nitrogen cryostat
With the boiling nitrogen we can:
Calibrate thermocouples and resistance thermometers with freely selectable calibration temperatures between -180 °C and -80 °C in the DAkkS nitrogen cryostat.
Use the boiling point of nitrogen and calibrate thermometers at -196 °C DAkkS.
put the argon triple point into operation at -189.3442 °C and carry out a complete ITS-90 DAkkS calibration in the temperature range from -189 °C to 0 °C.
The fixed points used are:
Argon triple point -189,3442 °C
Mercury triple point -38,8344 °C
Water triple point 0,01 °C
Technical background
Calibrating thermometers at extremely low temperatures is a technical challenge. Conventionally, calibration baths or temperature block calibrators are used to calibrate thermometers in the negative temperature range. However, these quickly reach their limits when cooling and are only used down to around -80 °C.
Calibration baths are cooled with compressors. To ensure stable control of the calibration temperature, an electric heater works ‘against’ the compressor, which always cools at maximum power. In addition, the calibration media used (such as silicone or ethanol) change their viscosity considerably and absorb water from the ambient humidity. Both of these factors make it difficult to control the temperature of the calibration baths. The lowest temperature that calibration baths with stable control can reach is around -80 °C.
Temperature block calibrators are cooled with Peltier elements or Sterling motors. These technologies are limited and can be used down to about -50 °C with Peltier elements or -100 °C with Sterling motors.
To overcome these limitations, we use liquid nitrogen as a ‘cold source’. This enables us to extend the temperature range when calibrating thermometers down to -196 °C.
New digital archive Klasmeier Cloud:
Calibration documents quickly and easily available
The new Klasmeier Cloud – the perfect archive for all calibration documents. From now on, our customers will find a QR code on all devices calibrated by Klasmeier, with which they can quickly and easily access our digital archive.
Especially useful: In addition to all calibration documents, the contact details of the relevant contact person at Klasmeier are also always available there. So even five or more years from now, if you have any questions about your calibration product, you can find the information you need with just one click.
Finding the right calibration solution for you
Questions about our calibration services?
Please send your questions or enquiries to Mr Boris Kalb:
b.kalb@klasmeier.com
+49 661380 940-0