By forming a bimetal strip into a dome shape (hemispherical, dished shape) to acquire snap action, the disk type thermostat is characterized by its simplicity of construction. The simple design facilitates volume production and, because of its low cost, account for 80% of the entire bimetallic thermostat market in the world.
However, the bimetallic material has physical properties similar to ordinary steel material and is not a spring material in itself. During the course of repeated tripping, it is no wonder that just a strip of ordinary metal, formed into a dome, will progressively distort, or lose its shape, and return to its original shape of a flat strip.
The life of this style of thermostat is generally limited to several thousand to tens of thousands of operations at best. Although they demonstrate almost ideal characteristics as protectors, they fall short of being qualified to serve as controllers.
Post time: Feb-21-2024