Today, digital thermometers have become essential tools for measuring temperature in various applications. These modern devices have largely replaced traditional thermometers, such as mercury ones, thanks to their accuracy, ease of use, and quick response. But do you know how this tiny device measures body temperature?

1. Semiconductor Thermistor: One of the key components in a digital thermometer is the semiconductor thermistor. This device, made of materials such as metal oxide or conductive polymers, has the property of changing its electrical resistance in response to changes in temperature . The variation in the resistance of the thermistor is proportional to the measured temperature. Using a suitable electronic circuit, the thermistor converts resistance changes into electrical signals that can be interpreted as temperature values.

2. Analog-digital conversion circuit: In order to display the temperature on a digital display, the analog signal generated by the thermistor is converted to a digital signal by an analog-digital conversion circuit . This circuit takes the electrical signal and divides it into a series of discrete levels that can be represented as digital numbers. These digital numbers are processed and translated into a temperature reading on the screen.

3. Calibration and compensation: The accuracy of digital thermometers is further improved by calibration and compensation. During the manufacturing process, thermometers are tested and adjusted to ensure that the measurements are as accurate as possible. In addition, compensation features such as non-linearity correction, temperature drift adjustment, and compensation for sensor drift can be incorporated to ensure more accurate and reliable measurements.

In short, when the temperature sensor is placed on the object or medium to be measured, the thermistor detects and records the changes in electrical resistance that are caused by temperature changes. The resulting electrical signal is sent to the analog-digital conversion circuit, where it is converted to digital values.

These digital values ​​are processed and presented on the thermometer's screen, showing the temperature reading in degrees Celsius or Fahrenheit. Thus, the time required to obtain a stable reading depends on the speed of response of the thermistor and the design of the processing circuit, but in general, modern digital thermometers provide fast and accurate measurements.