What is the term for a device that senses room temperature and controls heating or cooling equipment?

The correct term for a device that senses room temperature and controls heating or cooling equipment is a thermostat. A thermostat works by measuring the ambient temperature of a room and, based on pre-set temperature settings, signals the heating or cooling system to turn on or off to maintain the desired temperature. This regulation helps ensure energy efficiency and comfort within a building or space.

In contrast, a thermocouple is a sensor used to measure temperature, typically in an industrial setting, but it does not control heating or cooling systems directly. A relay is an electrical switch used to control a circuit; while it can be part of the system that a thermostat operates, it doesn't actively measure temperature or control environmental conditions. A sensor, while a broader category that includes devices like thermocouples, doesn't specifically refer to the temperature control function of a thermostat. Therefore, 'thermostat' is the most precise term for the device described in the question.