| 摘要 |
PURPOSE:To allow easy and direct fluidity measurement of powder material through a simple downsized structure by comparing resonance frequency between a case where a piezoelectric oscillator generating thickness slip oscillation touches the powder material and a case where the piezoelectric oscillator does not touch the powder material. CONSTITUTION:Self-excited oscillation circuits 11, 22 constituted, respectively, of piezoelectric oscillators 1, 21 made of same material and having same profile and function are connected in parallel and outputs from two sets of circuit 11, 22 are fed to a phase discriminating circuit 23. Since the oscillator 21 of the circuit 22 does not touch the power material, oscillation frequency thereof matches the oscillation frequency f0 of the oscillator 1 under powder-free condition and the oscillator 1 oscillates at frequency f'0 upon touching the powder material. These two frequencies f0, f'0 are fed to the phase discriminating circuit 23 where frequency difference DELTAf0 is determined and used for determination of the fluidity of powder material. |
