When the piezoelectricity particle generates the piezoelectricity phenomenon with a certain frequency on the internal vibration board, the vibration board shows contraction and expansion, and the external detection pipe connected to the board also vibrates together. When the measured powder reaches the detection pipe, the pipe’s vibration stops, and the vibration acceleration pick-up piezoelectricity particle bears loads; this phenomenon is detected by signals, which is the principle of this device’s operation. Not like most of the Tuning Fork types with two external vibration boards, it is a product designed uniquely with one pipe. Its response capacity to fine powders (with ultra light gravity) and powder build-up is one of the world’s best in its reliability.