| 摘要 |
808,274. Photo-electric detection. KELVIN & HUGHES Ltd. Feb. 15, 1956 [Feb. 21, 1955], No. 5176/55. Drawings to Specification. Class 40 (3). [Also in Groups XXXVIII and XXXIX] In an ultrasonic pulse-echo system for detecting flaws in a solid object (see Group XXXVIII) the echo pulses deflect or modulate the intensity of the linear trace of a cathode-ray oscilloscope, Fig. 4 (not shown), whose screen is focused through an apertured mask, Figs. 5 and 6 (not shown), on to a photo-cell controlling a visual or aural scanning indicator, the mask being adjusted so that the aperture corresponds to a desired range increment. A variable opacity filter may be used to give a linear relationship between the amplitude of the echo and the photo-cell output. A plurality of such devices may be used with the apertures set for different range increments or the image of the screen of a single cathode-ray oscilloscope may be projected by a rotating mirror on to a single aperture to scan the range trace. |
