Abstract: A system for visually determining the distance to an object includes a lens that is adapted to be sighted upon an object, said lens being divided equally in a first direction with each half covered by polarizing masks arranged at right angles to each other, a flat light transmission analyzer positioned in the vicinity of the focal plane of the lens and dividing the field of view thereof in a second direction displaced 90.degree. with respect to said first direction, each half of the analyzer being covered by polarizing elements arranged at right angles to each other, and calibrated means to indicate the relative position of adjustment of the lens and analyzer when the observed images at the opposite sides of the divided field of view are in coincidence.BACKGROUND OF THE INVENTION1. Field Of The InventionThis invention relates to an improvement in an optical apparatus for visually determining the distance of an object.2.

Abstract: A closed system couples the inlet and outlet pressures generated by a centrifugal pump to a pair of flexible diaphragms which seal the flow tube in a pressure rebalance system for measuring fluid flow. The system is filled with a conducting fluid which forms certain resistance paths whose resistance varies with diaphragm position. This resistance change is used to generate signals which control the pump motor to the end that the diaphragms maintain a predetermined position and the pump head is equal to the differential pressure.

Abstract: A dual limiter circuit for limiting an input signal between high and low limits and having a first and a second operational amplifier with the positive inputs of the amplifiers being supplied with respective threshold, or limit, signals. A third operational amplifier has its positive input supplied with an input signal to the limiter circuit. A respective output impedance for each amplifier connects the output of the corresponding amplifier to the output of the limiter circuit while a feedback connection from the limiter output circuit is connected to the negative inputs of all three amplifiers. This dual limiter circuit operates for all values of the input signal to have one of the amplifiers operating in its linear region to control the output signal from the limiter circuit while the other two amplifiers are operated in saturated states in opposite senses.

Abstract: A multiple input switching system includes an input isolation device, such as a transformer, in the input circuit. Switching devices are provided for sequentially connecting the several input circuits to a time-shared amplifier. The switching devices are actuated at a predetermined rate with a predetermined closed-time for each closure. Further switching devices are provided for transferring the data from each of the input circuits to a corresponding memory device. These further switching devices are operated synchronously with the first-mentioned switching devices but with a shorter close-time. The data values in the several memory devices may be selectively scanned asynchronously. Between each actuation of the input switching devices, additional switches are actuated which (1) short-circuits the input to the amplifier and (2) applies the output drift signal of the amplifier to a compensating storage capacitor.

Abstract: A mounting arrangement for a recording head provides for an adjustment of the alignment of the face of the recording head relative to a recording medium disposed in a sliding contact relationship with the face of the recording head.