Which type of thermometer uses infrared rays to measure temperature inside the ear?

The tympanic thermometer is designed specifically to measure temperature inside the ear by using infrared technology. It works by detecting the heat emitted from the eardrum, providing a quick and accurate reading of core body temperature. This method is particularly useful as it can be done in a matter of seconds and is less invasive than other types of thermometers.

Each of the other types of thermometers serves different functions. A digital thermometer typically measures oral, rectal, or axillary temperatures using a probe and displays the reading digitally, but it does not use infrared technology. An app-based thermometer requires a smartphone and is typically not a standalone device that measures temperature directly; it might rely on other types of thermometers to read the temperature and then relay that information to a smartphone application. A temporal thermometer measures the temperature of the forehead with infrared technology but is not used for measuring ear temperature specifically.

Hence, the tympanic thermometer is the correct choice, as it is uniquely suited for measuring ear temperature using infrared rays.