| 摘要 |
An optical time range reflectometer for determining the attenuation of an optically conductive filament 6 comprises a source of light 3 controlled by a pulse generator 1, a ray divider 7, a detector 8, an amplifier 9, a signal processor, an indicating device, and control means 2. The signal processor comprises a sample-and-hold circuit 10 by means of which a back-scatter signal periodically received is scanned under control of a unit 2 (Fig. 2) containing two ramp generators each having different characteristics to produce a series of sample commands which are increasingly displaced relative to the trigger pulse. <IMAGE> |
