Resistance Thermometers

VIRA Resistance Thermometers, also known as RTD temperature sensors, measure temperature through the predictable change in electrical resistance of a sensing element. They are widely used where stable, accurate and repeatable temperature measurement is required, particularly in low-temperature and precision process applications.

Pt100 and nickel resistance elements are commonly used in resistance thermometers. Pt100 sensors provide 100 ohms of resistance at 0°C and are widely selected for industrial temperature measurement. Depending on the selected sensing element, configuration and tolerance class, resistance thermometers can cover a broad measurement range; platinum elements are suitable for applications from -200°C to +850°C.

Resistance thermometers can be supplied with 2-wire, 3-wire or 4-wire connection arrangements. Three-wire and four-wire configurations help reduce the influence of cable resistance, particularly where long cable runs are required. Sensor elements can be mounted in protective sheaths selected according to the process, with stainless steel 304 or 316 options available for applicable conditions.

Correct selection should consider the temperature range, tolerance class, sensor element, response requirement, insertion length, protective-sheath material, process conditions and connection method. For accurate measurement in flowing media, the sensor should be installed with sufficient immersion length and in the direction of flow where applicable.