The reading is made by measuring the amount of infrared energy emitted by the eardrum, the same way the temperature of stars and planets is measured. This thermometer gives a virtually instantaneous reading . A. No, a digital thermometer is not a form of mercury thermometer. Digital thermometers use electronic circuits and devices to show temperature measurements. These thermometers display the measurements as numbers.
Digital thermometers measure temperature by means of a slender device called a probe.
The probe is made of either a metal, such as copper or platinum, or a semiconductor. Temperature changes cause a large variation in the electrical resistance of these materials. Most semiconductors are more sensitive to temperature changes than metals. The probe is connected to an electronic circuit. The circuit receives temperature readings from the probe in the form of electrical signals.