The Perkin-elmer Corporation

Robert A Hoult

David H Tracy

Robert P Ragusa

Charles F DEMey, Ii

Juan C Ivaldi

Richard Spragg

A method for determining concentration of an analyte in a sample includes generating a spectrum of a selected analyte and interferents, generating a spectrum of an unknown sample, computing first and second derivatives of the sample spectrum, deriving a matrix model that includes the analyte spectrum and the derivatives, and applying the matrix model to the sample spectrum so as to yield a parameter representing concentration of the selected analyte in the unknown sample. Multiple linear least squares regression is utilized to fit the model and calculate the parameter.

Method and apparatus for comparing spectra

An optical transmittance apparatus has a pair of reference channels of glass rods and a pair of sample channels containing sample fluid. A beam splitter and mirror pass a first portion of an incident beam through an ingoing reference channel, and a second portion through an ingoing sample channel. The first portion is reflected back through an outgoing reference channel, and the second portion back through an outgoing sample channel. The beam splitter and mirror directs the outgoing beams into a common outlet path. A partial disk selectively passes either portion. For positioning the disk, poles of a magnet mounted on the disk axle face windings made about an axis perpendicular to the axle, the windings being on the opposite side of a barrier plate from the poles. Current of one polarity through the windings effects one orientation of the disk, and reversed olarity reorients it perpendicularly.

Optical transmittance apparatus for fluids

In optical device for measuring displacement an optical grating is formed of alternating transparent and opaque stripes having equal widths. The grating is in an aperture plane with the stripes parallel to a central plane that is perpendicular to the aperture plane. Respective subpluralities of the stripes are located in an aperture area in the aperture plane, so that incident light rays on the aperture area are at least partially passed as beams by the transparent strips in the aperture area. A concave mirror has it center of curvature at the aperture area so as to return the beams back to the aperture area. The return beams are further passed by the transparent strips in the aperture area as return light. The grating is displaceable laterally to the cental plane, such that a corresponding responsiveness of the return light intensity to the lateral position provides a measure of displacement of the grating relative to the central plane. Alternative device with reflecting strips function similarly.

Optical device for measuring displacement

An optical probe is for measurement of light transmission of liquid. A tubular housing three equally configured legs defining three arcuately spaced openings in the housing wall. A solid cylindrical member formed of glass or fused silica has a flat transparent end surface and an opposing curved surface silvered to form an internally concave reflector. The cylindrical member is retained in the housing with the transparent end surface adjacent to the openings. A transparent rod member has a flat first end surface and a flat second end surface parallel to the first end surface. The rod member is retained in the housing with the second end surface adjacent to the openings and spaced from the transparent end surface parallel thereto so as to define a cavity therebetween such that, upon immersion of the probe, liquid passes through the openings into the cavity. The first end surface is spaced from the concave reflector so that conjugate focal spots of the concave reflector are located at the first end surface. Two first optical fibers are affixed respectively to the focal spots. Light entering through one optical fiber passes twice through the liquid in the opening while being reflected by the concave reflector into the other optical fiber.

Optical probe for measuring light transmission of liquid

An optical switching device includes a first optical fiber terminating in a first window, and a plurality of second optical fibers each terminating in a corresponding second window. A concave mirror is selectively positionable with conjugate foci located respectively at the first window and selectively at any one of the second windows so as to reciprocally image the first window and a selected second window on each other. The imaging mirror is rotated about an axis spaced from and parallel to the optical axis of the mirror, so as to rotate the mirror among a plurality of arcuately spaced selected positions. In each selected position the imaging means closes a light circuit between the first optical fiber and a selected second optical fiber.

Optical switching device

In a method and a system for analyzing spectral data including a spectrophotometer and a spectral detector, a data station receives first transmittance spectrum data points and has a file register containing second transmittance spectrum data points. The first and second transmittance data points are transformed respectively to set of first and second absorbance spectrum data points. The first and second absorbance points are band pass filtered at a characteristic frequency nominally associated with spectral bandwidth so as to produce respective sets of first and second filtered data points. A set of weighting factors are established, each corresponding to the square of the sum of a first transmittance point and a second transmittance point for a selected frequency. A comparison factor is generated as a normalized sum of products over a selected spectral frequency range, each product being formed of a weighting factor and corresponding first and second absorbance data points for each selected spectral frequency.

A method identifies components in a sample by spectrally analyzing the sample in a spectrophotometer. The sample data points output from the spectrophotometer are detected in a detector before being stored in an array in a data station. A preselected smoothing bandwidth is entered into the data station from a keyboard. The bandwidth is converted to a strength parameter; and thereafter each of the smoothed data points is stored before being output as an array of smoothed data points to form a modified spectral display, which identifies the components in the sample.

Interactive smoothing system

The invention is directed to a scanning Michelson type interferometer assembly which includes a beam splitter assembly for receiving a beam of radiation from a source, a stationary plane mirror for receiving and returning a first subbeam over a fixed optical path from the beam splitter assembly and an adjustable plane mirror for receiving and returning a second subbeam over a variable length optical path from the beam splitter, a system for receiving the combined output beam from the beam splitter assembly for forming a spectrum of the input beam radiation, a path difference generator having a pair of parallel spaced mirrors mounted so that the second subbeam is incident on one mirror and is reflected by both mirrors so as to emerage from this direction of incidence, the beam splitter assembly and the stationary plane mirror and the adjustable plane mirror as well as the optical path difference generator assembly being all mounted on a single, rigid monolithic structural frame to provide stability for the entire assembly, pins for forming a tapered track between the monolithic structural frame and the adjustable mirror, a ball mounted for sliding movement in the track, and a differential screw connected to the ball for driving the ball in the track to thereby adjust the tilt of the adjustable mirror, an E-shaped body portion mounted on the monolithic structural frame, which carries a pair of permanent magnets to provide an inwardly directed magnetic field, a scan motor armature coil assembly being mounted on the path difference generator assembly for movement perpendicular to the magnetic field when current is applied assembly in a direction substantially parallel to the to the coils, thereby to rotate the generator assembly, the beam splitter assembly including a beam splitter plate having a beam splitting coating on one surface, and a ring having an optical surface for receiving the plate, the monolithic structural frame having three spaced pads so that the optical surface if the ring can be flexably retained thereon for sliding radial movement due to thermal differential expansion, and a compensator plate being mounted adjacent the beam splitter plate for compensating for optical distortions of the beam of radiation due to the beam splitter plate.

Scanning Michelson interferometer assembly

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.

Detector preamplifier for use with a MCT detector

An assembly for positioning an optical element, includes a frame member having a base member affixed thereto, which base member carries an optical element rigidly affixed thereon. The base member is mounted to the frame member via a plurality of tilting means which permit the base member to be tilted with respect to the frame member in at least two orthogonal planes and thereby allows the precise alignment of the optical element.

Growing community of inventors

Bethel, CT, United States of America

Robert A Hoult