Bimetallic thermometer and glass thermometer PK

Bimetallic thermometer and glass thermometer are common thermometer table, a lot of people very easy to mix the two up, don't know some of the differences between them. Below, let the two thermometer big PK, distinguish between the two thermometer in different ways, let people better understand the difference between the two. Said, from the aspects of working principle of the bimetallic thermometer is the use of two different metal working in the principle of expansion degree of different temperature changes. The glass is according to the mercury thermometer, alcohol, toluene, etc liquid has obvious heat bilges cold shrink, made of the physical properties of the work is using the principle of liquid heat bilges cold shrink. Looked from the structure, main components of bimetallic thermometer 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. Glass thermometer is by temperature, expansion tubes and rod and other parts, generally speaking, there are internal standard and external standard type two kinds. Internal standard mercury thermometer scale divided on in the milky glass behind the expansion tubes, external standard type of the rod is directly on the glass tube. From the temperature measurement range and the application field, bimetallic thermometer temperature range is 200 ~ 650 ℃, the permissible error of scale range of about 1%, thus can be used to requirements under the condition of relatively high mechanical strength, widely used in industrial field, so to speak. Mercury in glass thermometer glass mercury thermometer and electric contact thermometer is commonly used in industrial boiler, external standard type is suitable for laboratory, used to measure the temperature of the liquid or gas. The interpretation of these three aspects, I believe you can better distinguish between bimetallic thermometer and glass thermometer, hope don't mixed up in use.