| 摘要 |
PURPOSE:To execute a continuous measurement at a high speed, and also to make a titled device small-sized, by detecting an interference fringe of laser light scattered by a filament, generating a gate which opens for a time corresponding to integer times of an interference interval from its signal, and detecting and displaying its opening time. CONSTITUTION:Laser light emitted from a light source 1 is scattered by a transparent filament 2, and a part of the interference fringe is reflected on a linear photodetector 3. As for a signal obtained by the linear photodetector 3, its scattered angle theta is converted to a time (t). From this signal, a gate which opens only for a time DELTAt corresponding to integer times of an interference fringe interval is generated by a gate pulse generating circuit 4, DELTAt is measured by a display part 5, and also DELTAt is converted to a filament diameter and is displayed. |
