A float switch based on a reed contact uses a magnet in the float, which floats on the liquid surface. When the liquid level changes, the float moves, and the magnet approaches the reed contact, which consists of two ferromagnetic blades within a glass capsule. When the magnet attracts the blades, they close, and the circuit is completed. This allows a signal to be sent, for example, to trigger an alarm or control a motor.

Temperature measurement is achieved using precise PT100 or PT1000 sensors, which exploit the change in resistance of a metal with temperature. A PT100 sensor has a platinum resistance whose value decreases as the temperature increases, while a PT1000 sensor has a resistance that is 1000 times greater. The resistance values of the PT sensors are converted into temperature values, which can then be transmitted to control and regulation systems to monitor the temperature and control processes.

The Bi-metal switch, made of two metal strips with different coefficients of thermal expansion, detects temperature changes through deformation when a specific threshold is reached. This deformation triggers mechanical movement, opening or closing the electrical contact. When the switch is open, the circuit is interrupted to prevent overheating. When the switch is closed, current flows to activate, for example, a fan or heating element.