Which device uses electrical circuitry to determine temperature changes?

The device that uses electrical circuitry to determine temperature changes is the electronic thermometer. These thermometers typically utilize sensors, often thermistors or semiconductor devices, which detect temperature changes by adjusting their electrical resistance. This change in resistance is then translated into a digital temperature reading, allowing for quick and accurate measurements.

Other devices like mercury thermometers and tympanic thermometers operate based on physical properties of materials or specific mechanisms rather than electrical circuitry. A mercury thermometer measures temperature changes by the expansion of mercury in a glass tube, and tympanic thermometers use infrared sensors to detect heat from the eardrum but do not necessarily rely on electrical circuits in the same way that an electronic thermometer does. Digital thermometers, while providing a digital display, are a subset of electronic thermometers, but they may not specify the use of electrical circuitry in the same context. Hence, the electronic thermometer is the most accurate choice based on the requirement for electrical circuitry involvement.