Choose the bimetallic thermometer table card should pay attention to what issues?

Bimetallic thermometer table card is used to display the temperature, the main function of general bimetallic thermometer table card has two kinds, one kind is the bottom of the aluminum, the other is a white background ( Is above the table card of the aluminum coated with a layer of white paint) 。 So when the choice should pay attention to what issues? The first is, of course, diameter, brand is to embed pan, so the diameter of the table card is not greater than the inner diameter of the pan; The second is the material; Choose white and aluminum background difference lies in the bimetallic thermometer working temperature range. There is a process problem, average temperature is below 250 c when choose aluminium base and white can be, but after more than 250 c temperature, could melt the paint of the white table card, so it's best to choose the bottom of the aluminum. The bimetallic thermometer is made of pan, table, table, cover, thermal feeling, joint and other accessories. It works by using the different expansion coefficient of two kinds of metal ( Or alloy) Piece together form a thermal components, generally made spiral wound, its end ( The free end) Equipped with a pointer. When the temperature changes, the thermal component of curvature change, free end rotation, drive the pointer indicates the temperature value on the dial.