Abstract: A method and apparatus to optimize a characteristic of measured data in an adjustable instrument for chemical analysis. The characteristic is measured at a plurality of adjustment points about a start point. Through parabolic interpolation of the data a conjugate vector is formed and the best operating point thereon is selected. Then measurements of the characteristic are taken as a function of the adjustable parameters about the best point on the conjugate vector. These data are used in a parabolic interpolation to define a second conjugate vector. The best operating point on the second conjugate vector is the optimum point of the instrument.

Abstract: The bearing structure includes a cylindrical air bearing for supporting the optical instrument element carrier, a linear drive motor for determining the translational position of the carrier, and a frictionless magnetic repulsion positioning structure for determining the rotational versus translational position of the carrier.

Abstract: In an interferometric apparatus the path of the output beam of a rotary Optical Path Difference scanning assembly leading to an electrically responsive detector is maintained substantially fixed in space for any scan angle within predetermined limits, thus obviating a serious drawback of a prior art proposal wherein the output beam translates significantly over the detector face with changes in scan angle, with the result that the detector output is vitiated by totally spurious variations of the energy reaching it.In one embodiment, the scanning assembly comprises a beam splitter having a semi-reflective layer the output face of which cooperates with the face of an output mirror normal thereto, the axis of rotation being substantially coincident with the line of intersection between the prolongation planes of the two faces. A Fourier Transform spectrophotometer embodying the assembly is also described.

Abstract: The present invention is directed to a gas control device for controlling the fuel gas and the oxidizing agent supplied to a burner in an atomic absorption spectrometer. The device includes a pressure controller and a downstream flowmeter, connected to the aforesaid pressure controller in each of the device's supply conduits to an atomizer, oxidizing agent port and full gas port of the burner. Each flowmeter employed in the preferred embodiment of the invention is comprised of a turbine wheel which is exposed to the gas flowing through the flowmeter. By the rotation of the turbine wheel output, signals are generated depending on the angular rate thereof and thus as a function of the gas flow rate. These output signals are input into a control unit and a set of servomotors, each associated with one of said pressure controllers, are reproducibly adjusted under the control of said control unit, even under unstable pressure conditions, to selected gas flow rates.

Abstract: A preamplifier network or circuit for converting non-linear signal information, such as is produced by a mercury cadmium tellurium (MCT) detector, to a substantially linear voltage signal output corresponding to the incident light levels on the MCT detector. Conceptually speaking, the subject preamplifier functions as a constant-voltage variable-current source to the MCT detector, and incorporates positive feedback for being effective as a negative resistance to nullify the MCT detector resisance introduced signal component of the signal information being monitored.

Abstract: A self-contained automatic computer controlled system for checking and recalibrating the wavelength scale of both monochromators of a fluorescence spectrophotometer is described. No operator adjustments are required. The system sets the wavelength of each monochromator to within 0.1 nanometers. Besides automatic indexing at turn-on the operation can be repeated at any desired time. The system is applicable to single or double monochromator instruments.

Abstract: A beam of radiation is directed into a liquid sample cell containing a sample to be analyzed in solution. The illumination emanating from the sample cell as a result of the beam of radiation from the radiation source is diffracted into a polychromatic spacially divergent beam and directed to a linear array of photovoltaic photodetectors with different spectral segments of the beam being intercepted by different photodetectors of the array. The signals from the photodetectors are separately and substantially simultaneously sampled and held to thereby obtain data usable for a high-accuracy wide-spectrum chromatogram.

Abstract: An apparatus for periodically monitoring the composition of a plurality of samples includes a plurality of stationary flow-through sample vials through which sample fluid is periodically passed. A sampling probe withdraws fluid from the vial for subsequent analysis.

Abstract: An adjustment device is provided having a block with two longitudinal bores therethrough joined by a slot. A movable member, having a threaded hole therethrough, is slidingly disposed in one bore, and a movable ball and a fixed member, having a curvilinear surface, are disposed in the other. A set screw, having a conical point, is inserted through the slot and screwed through the movable member so that the conical point engages both the fixed member and the movable ball. Further movement of the set screw forces the cone point between the fixed and movable balls, thus causing the movable ball to move away from the fixed ball.

Abstract: Output data from a spectrophotometer may be presented as a series of data values representative of the intensity amplitude of pass bands having equal bandwidths (resolution) and spaced at wavelength intervals equal to the bandwidth. For some purposes it is desirable to increase the bandwidth of said data, and this invention discloses method and apparatus for converting such data to equivalent data having a selected greater bandwidth.

Abstract: A digital gain controlled current to voltage amplifier having particular utility for interfacing with and forming part of a spectrophotometer system with a photomultiplier tube being responsive to light for producing an analog current proportional to the intensity thereof. The digital gain controlled current to voltage amplifier incorporates a current switched multiplying digital-to-analog converter inside its feedback loop. In this manner, the feedback loop impedance may be maintained constant as its gain is varied under control of a software programmed microcomputer.

Abstract: A sequential spectrophotometer system having a light source, a scanning type monochromator, a stepper motor means for changing the monochromator wavelength over a light spectrum being scanned, a photomultiplier for measuring the intensity of light absorption or passage through a sample being tested and generating a signal corresponding thereto, data acquisition means for compiling data corresponding to said signals and means for recording such data generally as a function of light measured for each wavelength, the improvement comprising:a method and means to effect the data acquisition conversion at or about each desired wavelength during a respective stepper motor rotor displacement period, i.e., during each corresponding period of diffraction grating vibration or oscillation following a stepper motor disposition thereof to another wavelength position angle.

Abstract: A primary ion beam raster gating technique for secondary ion mass spectrometer system is disclosed. The system includes a primary ion gun which raster scans an area of the surface being tested which sputter etches a crater. After the crater is formed, a beam blanking circuit causes the beam to scan a smaller area at the bottom of the first crater thereby sputter etching a second smaller crater. During this phase, the ion beam does not hit the side wall of the first crater so that errors are not introduced into secondary ion measurement from the bottom of the second crater due to material from the side wall of the first crater being sputtered into the second crater.

Abstract: A software controlled automatic shutter is described which minimizes ultraviolet irradiation damage to optical components from a high intensity spectrophotometric light source. The shutter automatically opens when measurements are being made and closes when the photometer system is idle. The digital control system may be self contained so as to avoid complication of the main computer.

Abstract: A timing system for a spectrophotometer having a line driven chopper including a rotating disc with alternate open and opaque segments, index apertures in the disc spaced at invariant angular relationship to one of the open segments for providing indexing pulses having fixed time relationship to the light segments, and a programmable microcomputer assembly for generating a string of timing pulses for timing spectrophotometer operations and adjusting the rate of the timing pulses to provide a fixed number between indexing pulses in fixed phase relationship thereto.

Abstract: A liquid pump motor control for a liquid chromatograph. The control detects when the pump needs to be refilled. Then, the pump motor is accelerated at a first rate for a given number of pulses. Then the motor is accelerated at substantially its maximum rate until a selected maximum speed is reached. Thereafter the speed is maintained at its maximum until the time calculated to begin deceleration. The motor is then decelerated substantially at its maximum deceleration rate until the speed is close to the final desired speed. Then deceleration occurs at a slower rate for a fixed number of pulses. The number of pulses applied to the stepping motor from the beginning of acceleration until the end of deceleration is constant regardless of the beginning or ending pulse rates.

Abstract: A mud flap mounting device for use with a tractor trailer truck is disclosed comprising a frame member adapted for attachment to the tractor truck and having an upper surface with a trough therein, a generally L-shaped support rod having a first leg adapted for attachment to a mud flap and a second leg rotatably mounted to the frame member to rotate between a first position wherein the mud flap is adjacent a wheel to a second position 180.degree. therefrom, and biasing means for yieldably maintaining the support rod in the first position and alternatively in the second position.

Abstract: A camera mounting device for mounting a camera to a hunting rifle is disclosed comprising a first mounting bracket adapted to support a camera, a threaded fastener to detachably secure a camera to the first mounting bracket, a variable diameter clamp to clamp the first mounting bracket to the barrel of the telescope sight of a rifle, a cable release for remote actuation of the camera, a second mounting bracket connected to the cable release, and threaded fasteners for detachably securing the second mounting bracket to the trigger guard of a rifle so that actuation of the cable release is coordinated to actuation of the rifle trigger.