Mercury-in-glass thermometer the thermometer, the bulb is made to reach thermal equilibrium with a temperature standard such as an ice/water mixture, and then with another standard such as water/vapour, and the tube is divided into regular intervals between the fixed points. In principle, thermometers made of different material (e.g., coloured alcohol thermometers) might be expected to give different intermediate readings due to different expansion properties; in practice the substances used are chosen to have reasonably linear expansion characteristics as a function of true thermodynamic temperature, and so give similar results. The application of mercury (1714) and Fahrenheit scale (1724) for liquid-in-glass thermometers
Indoor–outdoor thermometer Indoor–outdoor thermometer An indoor–outdoor thermometer is a thermometer that simultaneously provides a measurement of the indoor and outdoor temperatures. The outdoor part of the thermometer requires some kind of remote temperature sensing device. Conventionally, this was done by extending the bulb of the thermometer to the remote site. Modern instruments are more likely to use some form of electronic transducer. In an indoor–outdoor thermometer based on a conventional liquid-in-glass thermometer, the stem of the outdoor thermometer is connected to the bulb by a long, flexible or semi-rigid capillary. The temperature scale is marked on the stem as usual. However, the