Thermometer 1665 Christiaan Huygens (1629–1695) suggested using the melting and boiling points of water as standards, and in 1694 Carlo Renaldini (1615–1698) proposed using them as fixed points on a universal scale. In 1701, Isaac Newton (1642–1726/27) proposed a scale of 12 degrees between the melting point of ice and body temperature. In 1714 Dutch scientist and inventor Daniel Gabriel Fahrenheit invented the first reliable thermometer, using mercury instead of alcohol and water mixtures. In 1724 he proposed a temperature scale which now (slightly adjusted) bears his name. He could do this because he manufactured thermometers, using mercury (which has a
Liquid crystal thermometer Liquid crystal thermometer A liquid crystal thermometer, temperature strip or plastic strip thermometer is a type of thermometer that contains heat-sensitive (thermochromic) liquid crystals in a plastic strip that change colour to indicate different temperatures. Liquid crystals possess the mechanical properties of a liquid, but have the optical properties of a single crystal. Temperature changes can affect the colour of a liquid crystal, which makes them useful for temperature measurement. The resolution of liquid crystal sensors is in the 0.1°C range. Disposable liquid crystal thermometers have been developed for home and medical use. For example if the thermometer is black