The difference between the bimetallic thermometer and thermometer in everyday life

Bimetallic thermometer is mainly used in all kinds of industrial occasions, not in daily life, we often use the tool, so a lot of people not know what he and the difference of the thermometer in daily life, so, today let us know how to make a distinction between bimetallic thermometer and ordinary thermometer. Bimetallic thermometer is the use of two different metal working in the principle of expansion degree of different temperature changes. Bimetallic thermometer is mainly used in industry of element is one with two or more pieces of metal laminate composed of multilayer metal together. 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. As a result of the spiral coil end fixed and the other end connected to a free rotating pointer, therefore, when the bimetallic strip feel the temperature change, Pointers can be on a circular dividing scale to indicate the temperature. This kind of instrument of temperature measurement range is - 80 ~ 600 ℃, permissible error are the range of 1. About 5%. The thermometer and the rod of glass liquid thermometer USES similar, but can be used under the condition of higher mechanical strength. Ordinary thermometer, usually refers to some glass thermometer. Based on mercury, alcohol, toluene, etc liquid has obvious physical properties of heat bilges cold shrink. Glass thermometer by temperature, expansion tubes and rod and other parts, generally speaking, there are internal standard and external standard type two kinds. Internal standard thermometer scale divided on thin tube expansion behind milky glass. The plate sealed in the glass with bulb protection shell. External standard thermometer has a thick glass tube, rod frame directly on glass tube on the surface, suitable for measuring the temperature of the liquid and gas in the lab.