Digital thermometers use temperature sensitive components, also known as temperature sensors (such as platinum resistors, thermocouples, semiconductors, thermistors, etc.), to convert temperature changes into electrical signal changes, such as voltage and current changes. There is a certain relationship between temperature changes and electrical signal changes, such as linear relationships, certain curve relationships, etc. This electrical signal can be converted into a digital signal using an analog-to-digital conversion circuit, namely the AD conversion circuit. The digital signal is then sent to a processing unit, such as a microcontroller or PC, and the processing unit calculates the digital signal with temperature through internal software to become a temperature value that can be displayed, such as 25.0 degrees Celsius, and then displayed for human observation through a display unit, such as LED, LCD or computer screen. The sentence is:. This completes the basic temperature measurement function of a digital thermometer.

The accuracy, stability, and temperature measurement range of digital thermometers vary depending on the sensors used, AD conversion circuits, and processing units. Therefore, it is necessary to choose a digital thermometer that meets the specifications according to the actual situation.

Digital thermometers come in handheld, disc mounted, and medical small volume versions, among others.