| 摘要 |
PURPOSE:To detect the variation of a fine gap from the voltage between a grounded material to be detected and a conductor provided above it, by applying specific DC voltages to the both. CONSTITUTION:The material to be detected is fed along the conveyance line consisting of plural rolls 2. A cylinder 3 is fixed at one terminal and fitted at the other terminal with a probe device 6 which has an oscillator 4 in a block, and an electric conductor 8 is further fitted through an insulator 7 by branching. A steel plate 1 is grounded through the rolls 2. A DC power source 9 applies the DC voltage between the conductor 8 and steel body 2. The voltage between the conductor 8 and steel plate 2 is compared by a comparator 13 with a reference voltage and when the former voltage drops below the reference voltage, an output 14 is sent out to trigger a thyristor 15; a specific current is supplied from a power source 16 to the cylinder 3, which is controlled to separate the probe device 6 and conductor 8 from the steel plate 1. |
