TMS01

The operating principle of Resistance Temperature Detectors (RTDs) is based on the characteristic that the resistance of metallic conductors changes with temperature. The core principle: when temperature varies, the amplitude of lattice vibration in metallic conductors such as platinum and copper changes, which impedes electron movement to different degrees and leads to resistance variation. Taking the Pt100 platinum RTD as an example, its nominal resistance is 100 Ω at 0 °C. The resistance increases by approximately 0.385 Ω per 1 °C rise, showing highly linear behaviour within a specified temperature range. In practical measurement, a constant‑current source or bridge circuit converts resistance changes into electrical signals. Three‑wire or four‑wire wiring eliminates lead‑wire errors, and resistance values are finally converted to temperature values by referring to international standard reference tables. Thermocouples feature simple structure and rugged construction. Thermocouple sensors measure temperature based on the Seebeck effect. Two dissimilar conductors form a closed loop. A tiny voltage difference is generated across the loop if the two junctions are at different temperatures. This voltage difference is called thermal voltage or thermoelectromotive force. Its magnitude depends on conductor materials and the temperature difference between the "measuring junction" (junction of the two conductors) and the "cold junction" (open‑circuit ends of the conductors). Therefore, thermocouples are generally used for temperature‑difference measurement. The absolute temperature at the measuring junction can be determined when the cold‑junction temperature is known, or separately measured and compensated. Standards IEC 60584 and ASTM E230/ANSI MC96.1 list common thermocouple conductor material combinations and their corresponding thermal‑voltage‑to‑temperature characteristics.

High‑end Application

The iTHERM TMS01 is designed in compliance with the highest safety standards and can be customized for different applications. Multiple bendable temperature‑measuring inserts enable full‑range 3D temperature‑profile measurement via a single process connection. The instrument can be used either with a thermowell or standalone. It features fast response time, high mechanical strength and replaceable sensors. It supports thermocouple, RTD technology or iTHERM StrongSens.