Abstract: An optical switch having a housing and optical fibers connectable to a light source and a light detector. The light source and light detector are located remote from the housing. The first and second light guide cables have distal ends positioned in a separator assembly and are optically aligned but separated by a gap. The switch includes a device to modify a light beam, and the device is usually adapted to removably occupy the gap. The switch may be embodied in a float.

Abstract: An optical switch having a housing, a light source and a light detector. The light source and light detector are located remote from the housing. The light source is connected to the housing with a first light guide, and the light detector is connected to the housing with a second light guide. The first and second light guide cables have distal ends positioned through the housing and are optically aligned but separated by a gap. The switch includes a device to interrupt a light beam that is usually adapted to removably occupy the gap. The switch may be embodied in a float.

Abstract: An optical switch having a housing, a light source and a light detector. The light source and light detector are located remote from the housing, The light source is connected to the housing with a first light guide, and the light detector is connected to the housing with a second light guide. The first and second light guide cables have distal ends positioned through the housing and are optically aligned but separated by a gap. The switch includes a device to interrupt a light beam that is usually adapted to removably occupy the gap. The switch may be embodied in a float.

Abstract: Systems and methods for fluid level detection are disclosed. In one embodiment, a sensor assembly includes at least one optical fiber adapted to at least one of transmit and receive an optical signal, and a moveable float member. The float member is adapted to move in a first direction as the fluid level increases and in a second direction as the fluid level decreases. The float member blocks the optical signal at a first value of the fluid level, and allows the optical signal to pass at a second value of the fluid level. The presence or absence of the optical signal is detected to determine the level of fluid.

Abstract: An optical switch having a housing, a light source and a light detector. The light source and light detector are located remote from the housing. The light source is connected to the housing with a first light guide, and the light detector is connected to the housing with a second light guide. The first and second light guide cables have distal ends positioned through the housing and are optically aligned but separated by a gap. The switch includes a device to interrupt a light beam that is usually adapted to removably occupy the gap.

Abstract: The present invention relates to a nondestructive method or inspecting defects of the cladding of a nuclear fuel rod, which is featured by a wave emitter obliquely discharging an inspection wave to an inspected tube and a receiver arranged at a side of the inspected tube with respect to the wave emitter. If liquid is accumulated inside the tube, the incident inspection wave will be refracted so that the receiver can receive the refracted inspection wave at a specific location. The method can determine whether liquid is accumulated inside the tube and further is able to detect the level of the liquid.

Abstract: A fiber optic liquid level detector uses optical fibers to detect the presence or absence of liquids. The waveguide properties of optical fibers tends to deviate from the normal dielectric interfaces so that a fiber immersed in a liquid has a reflection coefficient smaller than when surrounded by air. This is caused by the differences in refractive indices of liquid and air and is used to measure the amount of light transmitted or reflected by the fiber in the preserve or absence of a liquid.

Abstract: A fiber optic liquid level detector uses optical fibers to detect the presence or absence of liquids. The waveguide properties of optical fibers tends to deviate from the normal dielectric interfaces so that a fiber immersed in a liquid has a reflection coefficient smaller than when surrounded by air. This is caused by the differences in refractive indices of liquid and air and is used to measure the amount of light transmitted or reflected by the fiber in the preserve or absence of a liquid.

Abstract: An optical gauge for measuring the level of a liquid in a container comprises an elongate, tubular member with a central bore. A light source is positioned for projecting radiant energy into the bore along a length of the tubular member. An elongate light collector is spaced from the light source and extends along the length of the tubular member for receiving radiant energy from the light source. The light collector has opposite ends and is formed such that radiant energy incident on a length of the light collector is transmitted to the light collector ends. A light blocking member is located within the bore and extends between the light source and at least a portion of the elongate light collector for blocking at least a portion of the radiant energy from the light collector.

Abstract: An apparatus and method to measure a gap width distance, specifically the distance between the lip of a coating hopper and the tangential edge of a coating roller or the support on the roller, is disclosed herein. The apparatus includes a long range microscope coupled with a CCD camera to provide a computer with an image. From this image the computer calculates first and second derivatives of the light intensity values between each pixel and determines the pixel locations of the two edges.

Abstract: A liquid level monitor uses a tube to confine a float to a vertical path with a canister containing a lower liquid and an upper liquid which meet at a liquid boundary, the level of which is to be monitored. Light from a light-emitting diode is conveyed to a vertical position of the tube by an optical fiber. A second optical fiber is arranged in a diametrically opposed position of the tube to detect light transmitted across the tube from the first optical fiber. The float is more transmissive than either liquid. When the level of the boundary falls to the level of the optical fibers, received light increases. The second optical fiber conveys this return light to a photodetector, the output of which can be used to trigger an alarm indicating that the boundary level is low.

Abstract: Device for the detection of liquid surfaces including a light source sending light onto a liquid surface, an oscillation element which is moved toward the liquid surface and causes the liquid surface to oscillate upon contact with the surface. The surface contact is detected by a light detector which picks up the radiation reflected by the liquid. Upon contact with the liquid, the light sent out by the light source is modulated by the oscillations of the liquid surface. The so modulated signal can be selectively identified by the detector.

Abstract: An optical temperature compensated material level-interface sensing and control system which comprises an insertion probe (10), control circuitry and a housing enclosure (72). The probe (10) makes use of a pair of emitters and detectors, in which one pair is positioned across a channel (26) through which material passes and the other pair are mounted in a sealed tubular bracket. The first emitter and detector pair are optically active with respect to sensed material, and the other pair is optically isolated, but thermally active. The resulting signal is a function of the material's linear coefficient of absorption with the thermal influence being effectively canceled out. The outputs of the control circuit are user selectable and changeable. The device is able to detect material presence and identity for use in interface-level control applications through a wide range of pressures and temperatures in industrial applications.

Abstract: An optical bilge pump apparatus has two optical fibers with gaps cut therein and associated light transmitters-receivers. The apparatus is responsive to high and low liquid levels in the pump such that the pump is turned on when both gaps in the optical fibers are submersed in liquid, and the pump is turned off when both gaps in the optical fibers are not submersed in liquid.

Abstract: An electronic oil level indicator is provided to show the amount of oil in an oil pan of an internal combustion engine which consists of a perforated housing positioned in the oil pan, so that the oil in the oil pan will enter the housing. A mechanism is connected to the housing for producing light. A fiber optic bundle has a first end connected to the housing spaced away from the light producing mechanism within the oil. A display panel is remotely located from the housing with a second end of the fiber optic bundle connected thereto. The height level of the oil will control the amount of illumination from the light producing mechanism reaching the fiber optic bundle which in turn is carried to the display panel to allow a person to visually check the oil level on the display panel.

Abstract: An apparatus for preventing blocking of a measuring head intended for carrying out measurements on substances suspended in a flowing medium. A light beam is transmitted from a radiation source with a determined intensity which is essentially constant during the measuring process. the intensity of the radiation radiated from the medium is indicated with the aid of at least one radiation indicator. The electrical output signal of the radiation indicator is sent for evaluation to a signal processing device. An open measuring channel has two mutually opposing edges which are intended to be placed along the direction of medium flow. Radiation from the radiation source is emitted from the one edge and received at the other. Placed in connection with the measuring channel are radiation-conducting elements which are placed as close as possible to the outer part of the edges. All of the junctions between surfaces of different extension in the vicinity of the measuring channel are gently rounded.

Abstract: The basic concept of the fuel gauge of this invention is to make use of the difference in refraction of liquid and air by means of optical fibres. More particularly, the fuel gauge includes a first set of optical fibers connected to a light source, a second set of optical fibres connected to a display unit and an optical medium mounted between the first and second sets of the optical fibres in such a manner that the light transmitted through the first set of the optical fibres is allowed to enter the second set of the optical fibres only through those optical fibres which are submerged in fuel. The light transmitted to the second set of the optical fibres may be converted into a visual signal with an existing display mechanism.

Abstract: A passive transducer apparatus and method of use for producing a useful output light signal in response to a sensed condition. The sensed condition varies the light emitted from a first fiber optic light conductor that is apparently captured or detected by a second fiber optic light conductor. The light captured by the second or collector fiber optic member is the useful output signal which may be made proportional to the sensed condition. The apparent change in light capture may be caused by a relative change in geometry of the fiber optic members, by variation in the coupling fluid or by an external optical member.