| 摘要 |
PURPOSE:To easily control a void rate, by a method wherein a mean void rate within a specified cross-section is measured also at a high-speed transient phenomenon by finding a partial void rate distribution. CONSTITUTION:Radiation is irradiated toward a tube 105 over the rotation of a rotary disc 114 at a specified speed, a dumping is made corresponding to a partial void rate, only that which transmits a radiation transmitting hole 116 produces a radiation beam 113 to detect it. If one radiation beam 113 reaches an upper end, the next radiation beam 113 starts to scan. Meanwhile, the rotary angle of the rotary disc 114 is inputted as the numer of optical pulses transmitting a position detecting hole 120 to a pulse counting circuit 122. A detecting signal of a radiation detector 117 is amplified and converted into a voltage. Meanwhile, a pulse from a photo sensor 121 is converted into an analogue voltage. Further, a pressure is detected by a pressure sensor 139, and is converted into a voltage. From the above signals, a partial void is analogue-computed, and is inputted to a mean void rate computing circuit 147 to display a mean void rate after it is product-averaged. |
