Which device is used to monitor heated seat element temperature?

• A. Thermistor
• B. Thermocouple
• C. Thermometer
• D. Thermopile

Answer: (A)

Sensing the seat’s temperature relies on a sensor whose electrical property changes with temperature, providing a real-time feedback signal to the control system. A thermistor fits this role best because its resistance changes noticeably with temperature, especially in the small, comfortable range used for seat heating. The controller can read the resistance (or a voltage derived from it) and precisely adjust power to keep the seat at the desired temperature.

Thermocouples generate a voltage that also varies with temperature, but they’re less ideal for the tight, low-temperature range of seat heating and require more signal processing. A thermometer is a separate measurement device, not a built-in feedback sensor. A thermopile detects infrared radiation for non-contact temperature estimates, which doesn’t provide the direct, embedded temperature feedback the heater needs.