Abstract: An improved tympanic thermometer incorporates twin thermopiles, each including a set of sensing junctions and a set of reference junctions configured so that three of the four sets of junctions sense only the temperature of an ambient environment, while the fourth set of junctions receives energy from both the ambient environment and from the tympanic membrane of a patient whose temperature is being taken. The energy received from the tympanic membrane is intentionally not bandwidth limited, enabling an accurate temperature measurement to be calculated which is substantially independent of wavelength. A light pipe is optionally included to assist in carrying radiation from the tympanic membrane to the fourth set of thermocouple junctions used for temperature sensing. In the preferred embodiment a dielectric coating is internally applied within the light pipe, and interchangeable tubes may be provided which conform to the aural physiology of different patients, including children.