A temperature switch is an instrument that automatically senses a change in temperature and opens or closes an electrical switching element when a predetermined temperature level is reached. Figure 6.47 is an illustration of a common type of temperature switch which has an accuracy of ±1 F maximum.
This temperature switch is provided with an adjustment screw at the top end in order to change the actuation point. In order to facilitate its mounting on the hydraulic system whose temperature is to be measured, the bottom end of the switch is provided with threads. As in the case of pressure switches, temperature switches can also be wired either normally open or normally closed.