Abstract: Methods of and apparatus for identifying peaks corresponding to the same chemical component in a series of liquid chromatograms to identify the peaks without foreknowledge of the chromatographic behavior of any component in the sample, or even the number of components in the sample.

Abstract: A multiple piston assembly pump of the kind which provides an overlap between the flow output of the piston assemblies during a portion of the strokes of the piston assemblies incorporates a method and apparatus for reducing pulsations in the flow during the time when the pump is changing over from one piston pumping to the other piston pumping. A first fast control loop responds to pump output pressure and is operatively associated with a second slow control loop which responds to average pump speed. A sudden pump speed change is detected, and the pump is run in a constant pressure mode until the speed returns to normal.

Abstract: Amplified spontaneous emission is substantially reduced in a novel optical amplifier wherein the gain medium is disposed within a converging region of the coherent signal, which converging region terminates in a waist at or near a limiting stop or saturable absorber. In contrast to the converging coherent signal flux, the amplified spontaneous emission flux is nonconverging and therefore most of the latter is removed by a spatial filter or saturable absorber.

Abstract: A scanning apparatus and method for scanning a beam of light incorporate an optical system in which a rotatable wheel has a plurality of light deflecting facets on the periphery of the wheel. The incoming light beam is reflected by a routing mirror or a routing beam splitter cube onto a front face of a facet as that facet is rotated in line with the routing element. The beam is deflected as it makes its first pass through the facet, and a porro prism redirects the deflected beam back through the rotating facet so that the beam makes two passes through each facet rotating past the routing element. The scanning action is produced by the rotation of the facet in the path of both passes of the beam through the facet. The net result cancels the angular motion of the beam in one direction and adds to the angular motion in the orthogonal direction. Scanning action as produced by one facet is repeated for each facet located on the periphery of the wheel.

Abstract: A four-way valve for selectively controlling the application of fluid and exhaust pressures to opposite sides of a double acting cylinder utilizes a main valve spool that is axially movable in a valve housing defining ports respectively connected to opposite sides of the cylinder and to the pressured and inlet sides of a fluid pressure source. The spool valve is provided with an axial bore and a pilot spool is mounted in such axial bore. Radial passages are provided in the main valve spool connecting its exterior with the axial bore and external sealing portions on the pilot spool cooperate with the radial port so that in a neutral position of both the main valve spool and the pilot spool, no fluid flow occurs.

Abstract: A sampler for taking samples from multiple sources has a fixed, non-moving needle at a sampling station. A sample vial is lifted from a tray at the sampling station. The needle pierces the septum of the vial and enters the sample as the vial is lifted toward the needle. The sample vial is also rotated as it is lifted, and a bar code reader makes a number of spaced apart, helical reads on a bar code label attached to the vial for label identification of the sample. The needle includes an inner, sample needle and an outer, gas-pressurization needle. The sample is withdrawn by the positive displacement of a syringe connected to the sample needle. The combination of the gas pressurization within the vial and the positive displacement of the syringe insures movement of the sample and accurate control of the volume removed independent of the viscosity of the sample.

Abstract: A cold cathode gas discharge apparatus, of the kind in which ionized species are driven against a cathode by an electrical field to eject electrons from the cathode and to produce a discharge within a gas discharge confinement tube, has a cathode constructed for balancing the trapping rate and releasing rate of gas particles in the cathode to maintain a substantially constant gas pressure during the operating life of the gas discharge apparatus. The cathode has an active surface which forms a substantially reentrant cavity about the end of the gas discharge confinement tube.

Abstract: A four-bar alignment adjustment mechanism with elastic hinges enables the mirrors of a gas laser to be very finely tuned with accuracy. A 50.degree. rotation of the fine-adjust knob deflects the mechanism to produce a 1% drop in power from maximum. The system has little backlash and does not use an extra-fine screw to directly move the mirror plate.

Abstract: Autocorrelation traces of laser pulses of short duration are produced by a method and apparatus that uses a rotating glass block to vary the path length on a time scale rapid enough to display the traces on a synchronized oscilloscope. Both paths of a split input beam of a laser pulse pass through the glass block. Rotation of the glass block changes the relative time of travel for light pulses along the two paths. The paths of the two beam arms pass through the block from different directions at a relative angle chosen so that the relative travel time difference is nearly linearly related to the angular position of the block during its rotation.Autocorrelation with rapid scanning through rotation of the block enables measurement of repetitive laser light pulses of very short duration, down to the order of one picosecond.

Abstract: Two concave spherical metal mirrors are used to scan a continuous wave laser beam for heat treating of metals. The mirrors are rotated in opposite directions and each is tilted at a small angle with respect to its axis of rotation. The frequencies of rotation of the mirrors are made constant by a precision timing drive linkage which also allows for phase adjustment. The beam deflection from an individual mirror describes an ellipse, but the deflection when added to that from the second mirror with the proper phase relationship to the first is a straight line. The input laser beam, which is too large in diameter for heat treating, is made to converge by the two mirrors, oriented so as to compensate for astigmatism. Spot size and scan width are adjustable over a wide range, as is scan frequency, which is equal to mirror rotational frequency. The scan produces a uniform, time-averaged distribution of power on the work piece.

Abstract: A pump for producing a substantially smooth and continuous outflow of liquid at relatively high pressure has two piston assemblies flow connected in series. The first piston assembly includes a pressure piston having a long suction stroke and a relatively short and abrupt expulsion stroke. A valve at the inlet of the pressurization piston allows flow to enter (but not exit), and a valve at the outlet of the pressurization piston allows flow to exit (but not enter). The second piston assembly includes a damper piston which functions as a mechanically driven damper to smooth the outflow from the pressure piston. This smoothing is accomplished by storing of the liquid displaced by the expulsion stroke of the pressure piston and then delivering the stored pressurized liquid to the pump outlet during the suction stroke of the pressure piston.

Abstract: Chromatographic peaks of varying width are detected and integrated by a method and apparatus that uses only the leading edge of the peak itself to detect the onset of the peak and to select for integration of the peak a filter detector having a time constant which matches the filter characteristics to the signal being monitored.A plurality of filter detectors having different time constants are used for identifying the beginning of a peak. The output of all of the filter detectors is scanned to identify the onset of a peak, and the most appropriate filter detector is selected for integrating the peak.

Abstract: A dye laser is stabilized for operation at a narrow line width by a control system which utilizes two reference interferometers.One reference interferometer has a small free spectral range for stabilizing the frequency of operation of the dye laser at the relatively narrow line width, and the other reference interferometer has a free spectral range substantially larger than the first reference interferometer.The dye laser is servo locked to a side of a transmission fringe of the first reference interferometer to maintain operation at a selected frequency with the narrow line width in the absence perturbations that can cause a mode hop.When a perturbation does cause a mode hop, the second reference interferometer detects the extent and the direction of the mode hop. It then automatically stops the scanning system of the dye laser, resets the servo back to the selected frequency and restarts the scanning system of the dye laser in operation at the selected frequency, all within a short period of time.

Abstract: Parts having centered spherical surfaces are produced by a method and by a tool which seats an inner spherical end of each part on a very accurately generated spherical surface of the tool while a spherical surface is ground and polished on an outer end of each part. The ground and polished surface is formed concentric with the underlying precisely formed spherical surface of the tool or block. The seating of a part against the spherical surface eliminates problems of tilting of the optical axis of the part.A shell is attached to the spherical surface of the block, and a plurality of openings are drilled through the shell. The sidewalls of the parts are located and supported by the side surfaces of these openings so that the shell holds the parts against any lateral movement during the grinding and polishing operation. As a result the parts can be vigorously ground and polished while being held firmly in a fixed position. A single tool has a large number of openings in the shell.

Abstract: This invention provides a method and apparatus for controlling the digging depth of the bucket of a backhoe or an excavator so as to move the digging edge of the backhoe bucket in a plane parallel to an overhead reference plane defined by a rotating laser beam. The detecting means for the laser beam is mounted on a medial portion of the downreach boom and the control of the position of the bucket is accomplished by moving the outreach boom of the backhoe relative to the supporting platform so as to maintain the detecting means on the downreach boom in a fixed relationship with respect to the reference plane defined by the rotating laser beam.

Abstract: This invention provides a method for controlling the path of a crop spraying aircraft in making repeated traverses over a field to insure that each traverse is laterally spaced from the adjacent traverse by the proper distance to assure adequate coverage of the crop land with the material being sprayed and avoiding over-lapping or insufficient coverage of any portion of the crop land. In accordance with the method of the invention, the crop spraying aircraft carries a rotating laser beam transmitter and receiver, and the transmitted beam is reflected from a plurality of reflectors located on the ground at known positions relative to each other to provide successive reflections of the transmitted laser beam from which the angular positions of the aircraft relative to the reflectors may be continuously determined.

Abstract: A lightweight, portable laser beam level instrument has an optical path which includes a solid state light source; a pendulous, positive lens; a rotatable pentaprism or mirror equivalent; and a glass plate which is tilted to provide fine tuning. The level instrument also includes a damping mechanism, a waterproof enclosure and a clip-in battery pack.The solid state light source is a diode in a specific embodiment and produces an intense beam of rapidly diverging infrared laser light.The postiive lens is suspended below the diode at approximately the focal length of the lens from the diode to collimate the light. The pendulous suspension lens maintains the beam in a truly vertical position with respect to the earth to provide self-leveling in a limited range of movement of the instrument. The pentaprism or equivalent converts this vertical beam to a horizontal beam.

Abstract: A method and resulting laser tube apparatus constructed from a plurality of components adapted to be arranged in axial alignment and selfsupporting with respect to each other. The elements are adapted to withstand high baking temperatures and are provided at their mating surfaces with material capable of forming a flowable seal between the components during baking and subsequently solidifying to a hermetic seal upon cooling. End adjustment mirror mountings which combine adjustable functions together with desirable electrical properties are also disclosed, together with procedures for obtaining optical alignment of the resultant tube product.

Abstract: Ring configuration dye laser capable of supporting laser oscillations in the form of backward and forward running waves and including unidirectional polarization shifter for causing preferential oscillation of one of said waves in unidirectional, single frequency operation.

Abstract: A method and resulting laser tube apparatus constructed from a plurality of components adapted to be arranged in axial alignment and self supporting with respect to each other. The elements are adapted to withstand high baking temperatures and are provided at their mating surfaces with material capable of forming a flowable seal between the components during baking and subsequently solidifying to a hermetic seal upon cooling. End adjustment mirror mountings which combine adjustable functions together with desirable electrical properties are also disclosed, together with procedures for obtaining optical alignment of the resultant tube product.