A Pt100 or Pt1000 is a platinum resistance temperature detector (RTD) that measures temperature based on changes in electrical resistance. "Pt" stands for platinum, and "100"/"1000" indicates the resistance in ohms at 0 °C. Pt100 = 100 Ω, Pt1000 = 1000 Ω.
In contrast, a thermocouple (TC) measures temperature by generating a small voltage due to the thermoelectric (Seebeck) effect between two dissimilar metals.
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