The working principle of a tuning fork level switch is to vibrate the tuning fork at a certain resonance frequency through a pair of piezoelectric crystals installed on the base. When the tuning fork of the tuning fork level switch comes into contact with the measured medium, the frequency and amplitude of the tuning fork will change, and the switch alarm signal will be output by detecting the change in this physical quantity. The tuning fork level switch is almost unaffected by foam, turbulence, vibration and solid content, which can eliminate splash and avoid false alarm. In terms of temperature resistance, the regular model can withstand 150 ℃, and by adding a high-temperature extension sleeve, it can withstand up to 250 ℃, meeting the temperature requirements for use.