How to distinguish between bimetallic thermometer and mercury thermometer?

Thermometer is a kind of measuring instruments of medium temperature, common bimetallic thermometer, mercury thermometer, pressure type thermometer thermometer, household, etc. So how to distinguish between the thermometer? In fact the most fundamental distinction is different from their working principle. Today we first explain the bimetallic thermometer and mercury thermometer. The working principle of bimetallic thermometer is the use of two different metal elements in the expansion degree of different temperature changes the principle of work. Bimetallic thermometer is mainly used in industry of element is one with two or more pieces of metal laminate composed of multilayer metal together, in order to improve the temperature measuring sensitivity, is usually made of metal spiral coil shape, when multi-layer metal temperature change, the layers of metal expansion or contraction, makes the spiral coil rolled up or let go, because the end fixed and the other end of the spiral coil and a free rotating pointer is linked together, therefore, when the bimetallic strip feel the temperature change, Pointers can be on a circular dividing scale to indicate the temperature. The working principle of mercury thermometer is according to the principle of mercury heat from the cold of the physical properties of. Know they work, coupled with our using the environment, can choose the suitable thermometer.