Bimetallic thermometer table card is aluminum bottom good or white?

The bimetallic thermometer 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. Common bimetallic thermometer table card has aluminum base and white two kinds, what is good and white aluminum bottom? In fact this is not necessarily. Bimetallic thermometer table card, as we all know, the main function is used to display the temperature, and the white table the card is in the bottom of the aluminum sheet coated with a layer of white paint. The difference between these two kinds of table card there is a process problem, generally choose the bottom of the aluminum when temperature range is less than 250 c 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. So we can according to the actual need to choose the right.