Influence of Bellows Setting on Its Spring Rate and on Temperature Adjustment of Electromechanical Thermostats

The precision and stability of adjusted temperatures are critical requirements for electromechanical thermostats. The key element in meeting the requirement is a thermostat bellows. It is a convertor of pressure into force that actuates the mechanical system of the thermostat. Convolutions enabling the axial movement of the bellows cause that the bellows is partly behaving as a spring. Therefore, the bellows has its own spring rate. The setting of the bellows spring rate influences the critical parameters of the thermostat. The aim of the article is to find the difference between the setting done by bellows producer and setting done by thermostat producer and its influence on the thermostat adjustment.