Abstract: A method and circuit for controlling the amplification in a radiation-detecting avalanche diode in which the diode generates electrical signals dependent upon the received radiation. These electrical signals are fed to evaluating means and a control signal is derived from the diode having a frequency which differs from the frequency used in the evaluation means. The amplitude of the control signal is compared with a preset value and the supply voltage of the diode is varied in dependence upon this comparison for controlling amplification of the diode.

Abstract: Two embodiments of a device and method are disclosed for providing a correction factor for the velocity of electromagnetic radiation in air. The devices include a pressure-responsive vessel having a predetermined quantity of gas enclosed therein and means for sensing the size of the enclosed volume to provide a measurement of the correction factor. Means are also disclosed for employing a humidity responsive device for moving a scale so that the correction factor is also made responsive to the humidity.

Abstract: A measuring device is disclosed which can measure an angle or length and which employs either an angle or length measuring plate. The angle or length measuring plate has thereon at least one measuring scale which has a regular pattern along the majority of the lengths thereof and an irregular pattern on two portions thereof. A light beam shines through an optical system to pass through the measuring scale at two points and from there into a photo-detector. The light path is arranged to pass through the two irregular portions at the same time. Several embodiments of the irregular patterns are shown. A circuit is also shown to detect the irregular portions and employ it as a reference signal.

Abstract: An apparatus for visibly indicating a spatial plane is disclosed, including a light emitter for generating a beam of light, means for dividing said beam of light into a pair of light beams, and means for scanning that pair of light beams in a pair of planes, wherein the planes in which the light beams are scanned are adjacent, symmetrical, and on either side of the spatial plane which is to be indicated. Specifically, the light emitter is a laser, and the means for scanning the pair of light beams includes penta-prisms which are rotated for scanning purposes. Preferably, the light beams which are scanned include high and low tensity areas, and the low tensity areas overlap in the spatial plane to be indicated.

Abstract: An optical sight, which includes a light source and a lens system wherein the lens system is an image of the light source, serving as an aiming point to the pointer's eye. The lens system has a reflecting surface for reflection in the direction of the pointer's eye of radiation from the light source. Means are provided for making a periodic change of the luminance of the image of the light source with a frequency with the perceptibility range of the eye.

Abstract: The present invention relates to an apparatus for contactless measuring of dimensions of objects, in particular the measurement of the diameter of moving wire in a wire-mill, whereby the contours of the object in one dimension are arranged by means of an optical system to be projected on an opto-electrical member, the output signal of which being a measure of the dimension wanted.