Single bar vibration level switch is one of the vibration, it is not afraid of hanging material is not afraid of impact, no clamping problem, and more sensitive. Its cylindrical single probe rod structure determines its wider applicability to industrial sites. It uses the "resonance" principle of the tuning fork to generate vibration under the drive of the piezoelectric element. Only when the probe rod is surrounded by materials, the amplitude of vibration is sharply reduced, resulting in switching action.