RTDs & Resistance Temperature Detectors
RTDs & Resistance Temperature Detectors
Resistance Temperature Detectors (RTDs) measure temperature by correlating the electrical resistance of a metal element — most commonly platinum — to temperature. The Pt100 and Pt1000 are the most widely used RTD standards, offering exceptional accuracy, repeatability, and long-term stability compared to thermocouples. RTDs operate across a typical range of -200°C to +850°C and are used wherever high precision is critical, including calibration laboratories, pharmaceutical processing, semiconductor manufacturing, and aerospace testing.
Platinum Resistance Thermometers (PRTs) represent the highest-accuracy tier of RTD technology, used as primary and secondary reference standards in national metrology institutes and industrial calibration laboratories. Secondary Standard PRTs, such as those from Additel, are calibrated against primary standards and traceable to ITS-90. RTDs require a measurement circuit in 2-, 3-, or 4-wire configurations to eliminate lead resistance errors, with 4-wire setups used for the highest accuracy.
Typical Applications
- Primary and secondary reference thermometry in ISO/IEC 17025-accredited calibration laboratories
- Pharmaceutical and biotechnology process temperature control and FDA 21 CFR compliance
- Semiconductor wafer processing and cleanroom environmental monitoring
- Aerospace and defense thermal testing of avionics and structural materials
- Precision industrial process control in petrochemical and power generation sectors
- Calibration of temperature instruments traceable to ITS-90
Popular Brands
Additel manufactures secondary standard PRTs and RTD probes for metrology and calibration workflows. Fluke Calibration offers complete PRT solutions including reference thermometers and multi-channel readout systems. Other leading suppliers include WIKA, Omega, and Isothermal Technology (Isotech), known for standards-grade RTD sensors used in accredited laboratory environments.
