Abstract: An optic displacement sensor includes first and second optic circuits which optic circuits include di-directional means for a light supply path to and a light return path from a light reflecting surface means. The first optic circuit is a reference signal circuit, and the second optic circuit is a measuring signal circuit. Means are provided for directing light into the light supply paths for the pair of optic circuits, and means are provided whereby the light from the light supply paths of the pair of optic circuits is received by light reflecting means and at least partially reflected into the light return paths where it is detected. Further, the sensor includes means for adjusting the detected signal from one of the light return paths with respect to the detected light from the other light return path.

Abstract: An optic displacement sensor includes first and second optic circuits which optic circuits include bi-directional means for a light supply path to and a light return path from a light reflecting surface means. The first optic circuit is a reference signal circuit, and the second optic circuit is a measuring signal circuit. Means are provided for directing light into the light supply paths for the pair of optic circuits, and means are provided whereby the light from the light supply paths of the pair of optic circuits is received by light reflecting means and at least partially reflected into the light return paths where it is detected. Further, the sensor includes means for adjusting the detected signal from one of the light return paths with respect to the detected light from the other light return path.

Abstract: This electronic meter signalling device provides a means for converting a conventional meter or gauge into an electronic switch in which a number of electronic outputs indicative of conditions of the meter or gauge are provided. The meter signalling device comprises a capacitive coupling means used in conjunction with an indicator of the meter or gauge to form electric charge coupling paths at a number of predetermined scale conditions of the instrument. Electronic circuitry transmits a signal through each electric charge coupling path to a discriminating circuit to activate outputs indicative of the scale conditions of the instrument.