Express this in degrees Fahrenheit. 5. Two types of thermometers not mentioned in the article are the bimetallic thermometer and the Bourdon tube thermometer. He is the last man in the United States with the knowledge and experience to produce many of Kahlsico's highly specialized thermometers. In simple terms, a thermometer measures the expansion and contraction of the fluid inside a glass tube. Most materials, to some extent, expand and contract with changes in temperature.
Thermometers use fluids because they change dramatically, and the differences are easily observed.
In the 1700s, mercury became the fluid of choice for thermometers because it remains a liquid over a wide range of temperatures, it's easy to read and it doesn't adhere to the glass. Since glass is a poor conductor of heat, thermometers must be made very thin to provide an accurate reading of the atmosphere outside the glass. Changes in temperature are reflected when the fluid moves up or down the thin air bubble, or capillary, above the bulb. Imperfections in the capillary reduce the accuracy of the reading. Glass is made of sand.