What is the working principle of double metal refrigerator thermometer?

Bimetallic thermometer freezer, as a kind of temperature monitoring instrument, widely used in medicine, food industry, and is closely related to daily ordinary life. The working principle of double metal refrigerator thermometer is to put the two pieces of expansion coefficient difference is very big pieces of metal welded together. When the temperature changes, the difference is very big, caused the different expansion coefficient of expansion and contraction, the deformation of sheet metal bending. According to different deformation and produce different momentum, momentum to drive the connection shaft and the other end of the indicating needle, indicate the temperature. Common bimetallic thermometer mainly RT221 freezer, main parameters and specifications are as follows: model: RT221 refrigerator thermometer with belt hook type: refrigerator thermometer with hook material: all the SS304 stainless steel surface diameter: 63 mm temperature range: - 40 - 40 c: precision & plusmn; 1. Table: 5% glass this bimetallic thermometer fridge intuitive and convenient, safe and reliable, long life, high sensitivity, can hang on the wall or on the table. Should pay attention to clean up and check when using, regularly test the measured values.