WIKA

Thermometer in cryogenic design

Thermometer in cryogenic design - Innovative design for low-temperature measurements

Applications

  • Extremely-low temperature measurements
  • Applications with liquid hydrogen (LH2)
  • Cryogenic tanks
  • Cryogenic pipelines
  • Hydrogen liquefaction plants

Special features

  • Innovative design with high accuracy
  • Usable with all relevant thermometers
  • Approved for applications in hazardous areas

Description

Due to the global use of hydrogen, extremely low-temperature measurement during transport and storage is gaining an ever-greater relevance. With the cryo design, WIKA provides a suitable option for all relevant temperature measuring instruments for this demanding application.

In laboratory trials, resistance thermometers (Pt1000) and thermocouples (type E) were tested for their suitability in cryogenic applications. The special design of the cryogenic thermometer features a high accuracy of ±3 Kelvin at -253 °C [-423 °F] as well as high reproducibility.

The test data from laboratory investigations served as the basis for calculating new polynomials for Pt1000 resistance thermometers in the range of -258 ... -200 °C [-432 ... -328 °F] which are used in the configuration of WIKA transmitters.

FAQ

How thick is the wall thickness of an MI cable?

Most manufacturers give a minimum wall thickness which corresponds to 10% of the external diameter of the MI cable.

Why should Pt100 measuring circuits with reduced tolerance class A or AA per DIN EN 60751 be used in at least a 3- or 4-wire connection?

The 2-wire connection is not permissible for classes A and AA per DIN EN 60751 since here the internal lead resistance of the wires is added to the measured value. This will usually exceed the specified tolerance for the temperature sensor. A measu ...

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