lämpötähtäimet

Lämpötähtäimet, known in English as temperature gauges or thermometers, are instruments designed to measure temperature. They are fundamental tools in various scientific, industrial, and everyday applications. The principle behind most temperature gauges relies on the physical property of a substance that changes predictably with temperature.

Common types of thermal gauges include liquid-in-glass thermometers, which utilize the thermal expansion of a liquid, typically mercury or colored alcohol, within a sealed glass tube. As the temperature rises, the liquid expands and rises in the calibrated tube, indicating the temperature. Bimetallic strip thermometers work by using two metals with different coefficients of thermal expansion bonded together. When heated, one metal expands more than the other, causing the strip to bend, which can be used to move a pointer on a dial.

Digital thermometers often employ electronic sensors such as thermistors or thermocouples. Thermistors are resistors whose resistance changes significantly with temperature, while thermocouples generate a voltage proportional to the temperature difference between two dissimilar metals. These signals are then processed and displayed as a numerical temperature reading. Infrared thermometers, also known as non-contact thermometers, measure the thermal radiation emitted by an object to determine its temperature without physical contact.

The accuracy and range of a temperature gauge depend on its design and the materials used. They are essential for monitoring processes, ensuring product quality, and maintaining comfortable environments.