Resistance thermometry bridges

High-accuracy resistance thermometry bridges from WIKA

By using built-in or external standard resistors, resistance thermometry bridges measure resistance ratios with high accuracy, which are indicative of the temperature, among other things. These instruments are not only used in the field of temperature measurement, but − due to their high accuracy − also in electrical laboratories.

Where are precision thermometers used?

WIKA precision thermometers are used for high-accuracy temperature measurement. Due to their high accuracy, precision thermometers are used wherever the highest precision is required. Primarily, precision thermometers are used in the pharmaceutical industry, in laboratories, workshops and production. WIKA precision thermometers are also frequently used for the calibration of other thermometers. They thus serve as reference instruments in both factory and calibration laboratories for testing, adjusting and recalibrating various temperature measuring instruments.

Which functions does WIKA's model CTR2000 precision thermometer have?

The CTR2000 is used for high-accuracy temperature measurements in the range of -200 … +962 °C and is available as a 2- or 8-channel version. The precision thermometer test has an accuracy of 0.01 °C. The precision thermometer also features high user-friendliness and low lifetime costs. When calibrated probes are used with the CTR2000 precision thermometer, the calibration data can be stored in the unit's memory or in the probe's protected SMART connector.

The integrated calibration programme enables the precision thermometer to be recalibrated by using a calibrated, traceable reference resistance. With the use of SMART probes, the WIKA CTR2000 precision thermometer has even more functionality. Calibration status monitoring, for example, tells you, directly on the screen, when a SMART probe needs to be recalibrated. Another advantage is that a temperature monitor permanently checks the temperature of the SMART probes and updates their log as soon as they are outside the defined operating range, as this can affect the calibration validity of the probes.

What advantages does the model CTR3000 precision thermometer from WIKA offer?

With the CTR3000 multi-functional precision thermometer, WIKA supplies a highly accurate measuring instrument that supports a wide range of thermometer types, such as resistance thermometers and thermocouples. The CTR3000 offers an innovative and, for the user, an intuitive user interface, it is expandable up to 44 channels and has logger and scan functions. The CTR3000 precision thermometer is recommended for laboratory and industrial temperature measurement and also for calibration laboratories.

How is the calibration of precision thermometers carried out that use resistance thermometry bridges to ensure accurate temperature measurements?

Precision thermometers, based on the principle of resistance thermometry bridges such as the Wheatstone bridge, ensure accurate temperature measurements at the resistance thermometer (RTD). The calibration is crucial and, for this, the resistance value of the RTDs is measured at different known temperatures with a precise calibrator.

The bridge circuit, usually a voltage divider, enables the adjustment conditions to ensure accurate measurements. The internal resistance of the RTDs must be taken into account in order to precisely react to the conductivity and impedance.

The calibration involves both voltage measurement and current measurement, using a defined measuring current level. The measuring results are displayed on a voltmeter or a moving-coil movement and the reading represents the measured value of the RTD.

Calibration is carried out periodically to ensure long-term accuracy and traceability to international standards is essential. All these steps ensure reliable temperature measurements in various applications.


What do different abbreviations like RTD, PRT, SPRT… mean?

  • RTD (Resistance Temperature Detector) – a temperature sensor whose resistance changes with temperature
  • PRT (Platinum Resistance Thermometer) – RTD using platinum wire for the resistance element
  • Pt1000 – PRT with 1,000 Ohm at 0 °C
  • Pt500 – PRT with 500 ...

Will the WIKA Build ID replace WIKA item numbers in future?

No, the Build ID will not replace the WIKA item numbers. When you place an order, WIKA will always provide you with a WIKA item number, the standard validity of which is not limited in time.