Wear-resistant RTDs (or thermocouples) operate on the principle that the electrical resistance of conductive or semiconductor materials varies predictably with temperature; as temperature changes, the resistance of the sensing element (e.g., platinum wire) changes accordingly, and this variation is measured by a circuit and converted into a temperature reading; their durability stems from protective sheaths made of wear-resistant alloys or metal-ceramic composites with surface hardness of HRC 60–65, enabling resistance to abrasion, corrosion, and impact in harsh environments like power plant boilers or cement kilns, while three-wire connection technology minimizes lead resistance errors to ensure long-term stability and accuracy.