Lämpöfimmimittarit

Lämpöfimmimittarit, also known as thermofluidic thermometers, are devices used to measure temperature based on the thermal expansion of a liquid or gas within a sealed system. These thermometers typically consist of a bulb containing the thermofluid, a capillary tube, and a scale for reading the temperature. As the temperature increases, the thermofluid expands, causing it to rise in the capillary tube. Conversely, a decrease in temperature leads to contraction and a lower level in the tube.

The most common thermofluid used in these thermometers is mercury, due to its uniform thermal expansion, visibility, and high boiling point. However, due to mercury's toxicity, alcohol-based thermometers, often colored red or blue for visibility, are also widely used, particularly in less extreme temperature ranges. The choice of thermofluid depends on the intended application and the temperature range to be measured.

The accuracy of a lämpöfimmimittari is influenced by factors such as the uniformity of the capillary bore, the calibration of the scale, and the precision of the thermofluid's thermal expansion properties. These thermometers are generally robust and do not require an external power source, making them suitable for a variety of applications, including laboratory measurements, weather forecasting, and household temperature monitoring. Their simple design and ease of use have contributed to their widespread adoption over many decades.