| 摘要 |
PURPOSE:To measure quickly a particle distribution with high accuracy in a conduction type particle detector by analyzing the electric signal generated by the particle passing through a fine hole and selecting the waveform of only the distortion-free signal passing through the hole near the center thereof. CONSTITUTION:An insulator 4 having a fine hole 3 is provided in a particle suspension 2 and a potential difference is impressed to electrodes 5, 6 to allow the particle to pass through the hole 3 in the conduction type particle detector 7. Electricity is generated by the passage of the particle and is detected by a waveform processing unit 8. The electric signal has the waveform (c) when the particle passes near the center of the hole 3 and has the waveform (a) when the particle passes near the peripheral wall of the hole 3. The electric signal is differentiated and the time T1, T2 (T1>T2) when the differentiated waveform exists on the outside of the prescribed threshold (+ or -V0) between positive and negative levels and the time t1, t2 (t1>t2) when the waveform passes in the threshold are detected. The waveform (c) having less distortions is selected from the relation of the potentials with the time T1, T2, t1, t2 out of an in the threshold and the grain size distribution is calculated therefrom. |
