TST602

The operating principle of Resistance Temperature Detectors (RTDs) is based on the characteristic that the resistance of metallic conductors changes with temperature. The core mechanism: as temperature varies, the amplitude of lattice vibration in metallic conductors such as platinum and copper changes, resulting in different levels of obstruction to electron movement, and thus varying resistance values. 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 for every 1 °C temperature rise, showing high linearity within a certain temperature range. In practical measurement, a constant‑current source or bridge circuit converts resistance variations into electrical signals. Three‑wire / four‑wire connection eliminates lead‑wire errors. Finally, resistance values are converted into temperature values according to international standard conversion tables.

It can be installed simply, quickly and directly onto pipe or vessel walls without process connections, resulting in a wide range of applications, such as verifying other measuring devices or performing temporary temperature measurement without interrupting the process. Its design is especially suited for HVAC and general applications in building automation and heat exchangers.