Description
Temperature difference thermometer for measurement of vertical temperature gradients and precise temperature measurement.
- Temperature range: -100 °C to 660 °C
- small measurement uncertainties: 6 mK and 25 mK
- Measurement of vertical temperature gradients
- Temperature standard and temperature difference thermometer
The thermometer for temperature differential measurement is a practical helper in daily laboratory work. The thermometer facilitates the work at the:
- Determining vertical temperature gradients
Vertical temperature gradients must be determined as part of the measurement uncertainty of a calibration (e.g. according to DKD-R 5-4 “Calibration of block calibrators”, DKD-R 5-3 “Calibration of thermocouples” or DKD-R 5-1 “Calibration of resistance thermometers”). - Optimizing calibration furnaces
When optimizing heating zones on calibration furnaces, such as the 3-zone high-temperature calibration furnaceor the Medusa calibration furnace, precise temperature differences must be measured. - Precise temperature standard
The main measuring point of the differential thermometer corresponds to the design of the eXacal Pt100 M and can be calibrated with the same measurement uncertainties. Thus, the differential thermometer can be used not only for measuring temperature differences but also as a temperature standard.
The differential thermometer consists of two Pt 100 temperature sensors positioned at the bottom of the thermometer and 4 cm apart.
Schematic design of the differential thermometer
Measurement uncertainty
eXacal thermometers can be calibrated in our own DAkkS calibration laboratory. The DAkkS accreditation ensures that all calibrations are traceable to national and international standards.
The calibration of the eXacal resistance thermometers is performed at ITS-90 fixed points. It is also possible to perform calibrations according to the comparison method in calibration baths and calibration furnaces. The measurement uncertainty is calculated from many components. The largest contributions are reproducibility, ITS-90 characteristic, self-heating and hysteresis.
With the differential thermometer, the main measuring point is calibrated at fixed temperature points. The second measuring point is measured by a differential measurement at maximum immersion depth in a heat pipe with an extremely good vertical profile.
- small measurement uncertainties with DAkkS calibration certificate
- Temperature fixed points from mercury triple point -38,8344 °C to tin freezing point 231,928 °C
- Differential measurement in a heat pipe / heat pipe furnace
| Temperature range | Method | Measurement uncertainty |
|---|---|---|
| -38,8344 °C – 0,01 °C | Mercury triple point | 6 mK |
| 0,01 °C – 29,7646 °C | Gallium melting point | 6 mK |
| 0,01 °C – 156,5985 °C | Indium melting point | 10 mK |
| 0,01 °C – 231,928 °C | Zinn melting point | 11 mK |
| 0,01 °C – 419,527 °C | Zink melting point | 21 mK |
| 0,01 °C – 660,323 °C | Aluminium melting point | 25 mK |
The specified measurement uncertainties correspond to k=2, include an ITS-90 characteristic curve and are given for the respective range.
More temperature difference thermometer
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