Abstract: An improved mirror alignment control for dynamically aligning the reflecting mirrors bounding the optical path in an interferometer comprises a closed loop servo control which utilizes a two frequency laser beam to provide phase comparison between beams traversing differing portions of the optical paths in the interferometer to determine alignment of the mirrors, said phase comparison providing a correction signal to direct multi-axial alignment of at least one of the mirrors.

Abstract: A mixing valve includes a housing having inlet ports and an outlet port that intersect at a valve chamber. A valve core within the valve chamber includes passages in fluid communication with the inlet and outlet ports. The passages intersect at a cavity within the valve core. An elastomeric seal retained within the cavity sealingly engages the valve core around the passages in the absence of fluid pressure in the inlets. Injection of a pressurized fluid in one of the inlets causes the seal to move away from both the corresponding inlet passage to permit fluid flow from the pressurized inlet port to the outlet port and compresses the seal around the other inlet port to provide a tighter seal than existed before application of pressure to the first port.

Abstract: A slotted retaining plate for use in a tubular reactor within an analytical system. The reactor contains inert packed material which provides for the necessary flow path length for a fluid stream entering the reactor. The retaining plate is extremely thin and has an array of slots which permit the necessary flow of the stream through the reactor, but retain the packing material within the reactor. The design of the slot array in the retaining plates essentially eliminates any possible impediment to the stream flow. The slots are adjustable to provide more flexibility in slot size control to allow use of smaller packing particles within the reactor and improve the instrument resolution in, for example, an amino acid analyzer.

Abstract: In a liquid scintillation counter, a standard radioactive source is supported in a bead position of a bead chain, flexible conveyor. The conveyor is guided for movement along a closed-loop conveyor path in sliding engagement within a conduit guideway for conveying the source between an operating position adjacent the counting chamber and a remote shielded position. The conveyor may support one or more sources for conveyance to one or more counting chambers along the conveyor path.

Abstract: A method and means for stabilizing the difference in frequencies between the frequency components of a two frequency laser beam influenced by Zeeman effect frequency splitting, accurately determines the frequency separation independently of the individual frequencies or intensities of either of the frequency components. Frequency stabilization is accomplished by mechanical and thermal adjustments to the lasing chamber length of the laser by a closed loop servo control referencing the frequency difference between laser beam components and a reference signal having a frequency equal to the desired frequency difference.

Abstract: A multicomponent quantitative analytical method and apparatus wherein the method includes the steps of and the apparatus is capable of performing steps of obtaining a plurality of calibration spectra, transforming the calibration spectra using a transform with orthogonal basis vectors, obtaining a calibration matrix relating the transform spectra to concentrations of analytes in the calibration samples, obtaining a spectrum for an unknown sample, transforming the unknown sample spectrum, and relating the transformed unknown sample spectrum to the calibration matrix to thereby determine the concentration of analytes in the unknown sample.

Abstract: A centrifuge rotor is presented having a pivotal mount for a sample container upwardly offset from the radial plane of maximal strength of the rotor permitting a smaller diameter rotor container assembly and reducing exposed surface area of the rotor container assembly.

Abstract: An improved mirror scan control for driving a movable mirror in an interferometer with a constant scan velocity comprises a closed loop servo control which provides constant velocity mirror scan in response to a phase comparison of a signal derived from the beat frequency of a two frequency laser beam passing through the interferometer and a selected frequency reference signal, wherein the difference in frequencies or beat frequency of the two frequency laser beam is stabilized at a specified difference in frequencies. The mirror scan control employs a phase lock control loop which locks the frequency of the referenced signal with the frequency of the signal derived from the laser beam to provide precise mirror velocity control.

Abstract: For use in a system for analyzing sample constituents by metastable transfer emission spectroscopy, an improved apparatus for mixing a sample gas with a metastable gas. The apparatus provides an unobstructed path for the flow of sample gas so as to minimize deposition of the sample on walls of the apparatus. The apparatus may comprise an annular manifold coaxially mounted around a conduit through which flows the sample, or it may comprise a collar detachably connected in line with such a conduit.