| 摘要 |
<p>1,233,463. Measuring coating thickness electrically. WESTERN ELECTRIC CO. Inc. June 19, 1968 [June 21, 1967], No.29125/68. Heading G1N. The thickness and eccentricity of the insulating sheath of an electric cable are determined capacitatively using electrodes 11, 12 in contact with diametrically opposite points of the sheath, the electrode support being rotated intermittantly to a plurality of fixed angular positions around the cable, and the electrodes being connected alternately, via a switch 21, to a bridge circuit 26 in each of the positions of the electrode support. The output of the bridge is displayed as a pen recorder 28, the bridge, Fig. 4 (not shown) containing a capacitor representative of the desired thickness of the sheath. The electrode support, Fig. 3 (not shown), is rotated by a motor 30 which is controlled by a relay 32 which also controls relays 33 and 34 for the pen of the recorder and the switch change-over. A control circuit for the relays is described with reference to Fig. 5 (not shown).</p> |
