The basic structure of a thermometer includes a glass bulb (temperature-sensing bulb), a capillary tube, scale lines, a temperature-sensing liquid (such as mercury or alcohol), and an outer casing. For example, a mercury thermometer indicates temperature by using the thermal expansion and contraction of mercury inside the glass bulb, causing it to rise and fall in the capillary tube.
The basic structure of a thermometer includes a temperature-sensing element, a signal conversion device, and a display module. For example, in an infrared thermometer, the temperature-sensing element is an infrared detector, the signal conversion device converts the radiation signal into an electrical signal, and the display module outputs the temperature value.
