What is commonly used and the design principle of the thermometer?

The thermometer, it is the floorboard of the temperature measuring instrument, can accurate judgment and measuring temperature. Application field widely, small to clinical thermometer, home indoor thermometer, big to the plant and all kinds of precision instrument is used on the thermometer. Its working principle is the use of solid, liquid and gas is influenced by temperature and heat bilges cold shrink phenomenon such as the basis for design. Can be roughly divided into kerosene thermometer, alcohol thermometer, mercury thermometer, gas thermometer, resistance thermometer, thermocouple thermometer, radiation thermometer and light thermometer, bimetallic thermometer etc. So what are their design basis? With work like, their design is based on the use of solid, liquid and gas is influenced by temperature and heat bilges cold shrink phenomenon; Under the condition of constant volume, gas ( Or steam) The pressure due to different temperature changes, the role of thermoelectric effect, resistance varies with temperature, the influence of thermal radiation, etc. Generally speaking, any physical properties of all matter, as long as it along with the change of temperature and drab, significant changes in, and made available to signal temperature thermometer.