Showing papers on "Spectrum analyzer published in 1989"

Automatic multiple-sample multiple-reagent chemical analyzer

Abstract: An analyzer for chemical assays includes a turntable (20) which supports sample containers (22) and reagent containers (24) within a cooled volume and test cells (26) about the periphery of the cooled volume. A probe (30) is carried by a rotating arm (32) for withdrawing liquid from the containers and dispensing the liquid. Fixed stations are also provided in the path of the probe. One such station (40) serves to both wash the tip of the probe and to receive samples for flow-through analysis. Heaters (44, 46) associated with the probe and with the test cells increase the rate of reaction. Curved walls of test cell segments match the optics of an optical analyzer so that light from the analyzer lamp (124) is generally orthogonal to the curved surfaces. The light voltage of the lamp may be controlled as a function of lamp wavelength required for particular assays. The system provides multiple-point calibration and automatic dilution of samples.

Multiple component gas analyzer

Abstract: A gas multiple component analyzer includes an infrared source that passes at least one measuring beam through a sample cell that contains the gas to be analyzed. Three measuring signals are generated in response to the measuring beam, and each is indicative of optical energy from the source transmitted through the sample cell in a respective optical region characterized by a respective optical center wave-length and a respective band pass. The three measuring signals are algebraically combined to automatically determine which of the three end gases is present in the sample cell in the greatest concentration, and the concentration thereof. The disclosed system measures concentration of three separate gases having overlapping absorption spectra.

A real-time autoregressive spectrum analyzer for Doppler ultrasound signals

Abstract: A system based on a digital signal processor and a microcomputer has been programmed to estimate the maximum entropy autoregressive (AR) power spectrum of ultrasonic Doppler shift signals and display the results in the form of a sonogram in real-time on a computer screen. The system, which is based on a TMS 320C25 digital signal processor chip, calculates spectra with 128 frequency components from 64 samples of the Doppler signal. The samples are collected at a programmable rate of up to 40.96 kHz, and the computation of each spectrum takes typically 3.2 ms. The feasibility of on-line AR spectral estimation makes this type of analysis an attractive alternative to the more conventional fast Fourier transform approach to the analysis of Doppler ultrasound signals.

Demodulation circuit for AC motor current spectral analysis

Abstract: A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

Self-contained, real-time spectrum analyzer

Abstract: A self-contained, real-time spectrum analyzer performs the function of spectrum analysis on one or more analog electrical signals. The analyzer consists of an oversampling analog-to-digital converter 104, which converts the input signal 100 to digital form. The digital signal enters a digital signal processing integrated circuit microprocessor 108, which is operated by a stored program 112 that includes a spectrum analysis program 116. The output 122 of the digital signal processor 108 can be converted to analog signals by digital analog converters 124 for display on an external oscilloscope. A variable frequency oscillator 200 controls the sampling of the analog-to-digital converter 104, providing continuously variable analysis bandwidth. The output of the digital signal processor 108 can be applied to a display register and driver 300, which changes the output into a data format 302 suitable for use by a flat screen display 304. Visual output is presented to the user on a flat screen display 304, such as a liquid crystal display or electroluminescent display.

Apparatus for estimating distortion resulting from compressing digital data

Abstract: Apparatus for analyzing distortion levels of samples which occur in data compression systems of the type that may be integrated into a data compression system or used as a stand alone analyzer. The apparatus includes a processor that is coupled to the data compression system to provide the distortion analyzing apparatus with necessary input bit allocation and power level data for each sample. Memory storage is coupled to the processor for supplying predetermined unique quantization error values corresponding to each transform coefficient representing samples of digital data in a frame of digital data to be compressed. The program in the processor calculates the estimated distortion value for each of the transform coefficients by multiplying power level values stored in the storage times the predetermined unique quantization corresponding to each transformed coefficient to provide estimated distortion values which may be summed over a frame of digital data to provide an average distortion level for a frame of digital data.

Correction for nonlinearity and polarization-dependent sensitivity in the detection system of rotating analyzer ellipsometers.

Abstract: Systematic errors due to nonlinearity and polarization-dependent sensitivity in the detection system of rotating analyzer ellipsometers are described. Post Fourier analysis procedures for detection and correction of these effects are presented.

Analyzer detector window and a method for manufacturing the same

Abstract: The invention relates to a detector window for an analyzer, particularly an X-ray analyzer, and to a method for manufacturing the same. The detector window is permeable to soft X-rays when the window is at least on one surface in contact with a pressure essentially equal to that of a vacuum. The detector window of the invention is a thin film, with the thickness of 0.5 μm, and is manufactured by means of photolitography.

Frequency transposing hearing aid

Abstract: The described hearing aid includes a frequency analyzer for classifying incoming sounds according to their frequency, and for selecting an appropriate transposition factor (the ratio of the information storage rate to the information retrieval rate) according to the appropriate one of several transposition factors inputted into the hearing aid based on the particular user's hearing characteristics for different frequencies. Also, described is an arrangement for minimizing loss of speech components containing the same frequency information by recirculating such speech components. Further described is an arrangement for reconstructing portions of the speech components according to their classification by the frequency analyzer in order to minimize loss of useful information in the output signal.

Identification of sampled data systems at frequencies beyond the Nyquist rate

Abstract: A practical algorithm is presented for identifying the dynamics of a continuous-time, linear, time-invariant system, embedded in a sampled feedback loop with fixed sample time, T It is shown that if the closed-loop configuration is stable, it is rather straightforward to design a set of experiments using a spectrum analyzer that will identify the plant transfer function to frequencies well beyond the Nyquist frequency Experimental results are included >

Particle analyzer apparatus and method

Abstract: A time-of-flight analyzer, such as a secondary ion surface analyzer, and method are disclosed wherein a beam of charged particles is created, magnified, directed along a path to a detector, detected and the time of flight measured. An emission lens is positioned on the path to produce the magnification and an additional lens can be provided along the path to produce variable magnification. A field aperture along the path limits the size of the image and a contrast diaphragm limits the lateral ion velocity. Two or more, preferably three, particle steering analyzers are sequentially positioned along the path from the emission lens to the detector with each of the three analyzers steering the particles through substantially 90 degrees.

Electrical energy analyzer

Abstract: An electrical energy analyzer including a computer for monitoring energy consumption and supporting ripple control is provided with improved A/D converter resolution by applying a 1/2 LSB square wave offset signal to the non-inverting input of a differential amplifier for amplifying a current shunt voltage. The amplifier output has limited filtering to allow a 1/2 to 1 LSB random signal to be applied to the measurement signal entering the A/D converter.

Laser operating device for intracavitary surgery

Abstract: This invention relates to an intracavitary laser operating device using a laser The device, has a catheter (2) accommodating laser light projecting fibers, a pulse laser oscillator device (1), an acoustic detector (4) detecting the acoustic wave generated from the diseased portion, an acoustic analyzer (5) analyzing the acoustic wave from the acoustic detector (4) and obtaining the amplitude change data and spectrum data of the acoustic wave, and a controller (7) for calculating the optimum condition of the projection of the laser light to be projected to the diseased part depending on the data from the acoustic analyzer (5) and controlling the pulse laser oscillator device (1) based on said optimum condition of the projection According the the device mentioned above, since the laser light can be projected to the diseased part based on the optimum condition of the projection, it is possible to avoid an occurrence of a risk that a normal blood vessel wall is damaged or carbonized or that a perforation in the blood vessel or new re-stenosis is formed

New tilted-poles Wien filter with enhanced performance

Abstract: The Wien filter is an E×B deflecting analyzer with the electrostatic field perpendicular to the magnetostatic field. The twofold functions of the Wien filter are as an energy analyzer as well as a mass analyzer. It has very high resolution for paraxial charged‐particle beams with V=E/B, the Wien velocity. Two Wien filters, a tilted‐poles Wien filter, and a classical parallel‐rectangular‐poles Wien filter were built and tested for electrons up to 3.5 keV and protons beams of 200 eV. (The tilted‐poles Wien filter is a new diagnostic developed by the authors.) The performance of the two is compared, and the tilted‐poles Wien filter has superior resolution to the classical Wien filter. Both Wien filters appear to have features useful for high‐temperature plasma diagnostics, including simultaneous measurement of energy and mass spectra, and high resolution.

Calibration and error correction for electrical-source-to-e/o-device impedance mismatch and o/e-device-to-electrical-receiver impedance mismatch in a lightwave component analyzer

Abstract: A lightwave component analyzer including at least an internal optical receiver and preferably also including an internal optical source which are selectively connectable by switches configurable by means of an instrument controller for calibration and performance of electro-optical, opto-electrical, and optical measurements. Transmission measurements of E/O devices are corrected for source match errors, and transmission measurements of O/E devices are corrected for load match errors, in addition to frequency response and cross-talk error correction. Response and match error correction provides for improved measurements of test devices with an electrical port having an impedance different from that of the measurement system impedance.

Method and apparatus for measuring the concentration of optically active substances

Abstract: The concentration of optically active substances is determined by measuring the polarization of light passed through the substance using a light source, a polarizer and a modulator operated at a predetermined modulation frequency fF, as well as a measuring cell, an analyzer and a detector. The output signal from the detector 16 is alternately integrated during each half period of the modulation frequency to form voltage values UI+ and UI-. These voltage values are stored and the quotient Q of these stored voltage values is formed. Subsequently, an adjustable constant voltage is subtracted from the quotient. The measuring arrangement can have a miniature design for implantation. No mechanically moving parts and only a single detector are used. The measurement is accomplished by a simple, miniature linear ray path having high resolution.

Real time monitoring of remote signals in an industrial environment

Abstract: A signal timing analyzer monitors a programmable logic control (PLC) of an industrial machine. Signal states of the PLC are sampled and the signal information is then transferred to a receiver card which is connected to a computer data bus. This allows the computer to monitor a piece of equipment by "eavesdropping" on the industrial controller that is actually operating and monitoring the equipment. The analyzer uses an on-board clock and timing circuit, so that the computer is not limited by the computer's clock speed in controlling sampling rates.

Apparatus for measuring optical properties of materials

Abstract: Apparatus for measuring an optical property of a sample including a source of radiation for exposing the sample to radiation of a predetermined wavelength; a detector for detecting the light intensity transmitted through the sample as a result of the exposure to generate a transmitted light intensity signal; circuitry for digitizing the transmitted light intensity signal; and an analyzer for determining the optical property from the digitized light intensity.

High efficiency power generating system

Abstract: A power generating system (10) in accordance with the present invention includes a converter (14) for producing an AC output (16) including a fundamental and at least one harmonic of the fundamental; a frequency analyzer (18), having at least one input coupled to the AC output, for providing an analysis of a frequency spectrum of the AC output; a processor (36), coupled to the frequency analyzer, for calculating at least one switching frequency, each switching frequency being used for transforming a different harmonic within the AC output back to the fundamental; a controller (34), responsive to the at least one calculated switching frequency, for producing control signals at the at least one calculated frequency for transforming the at least one harmonic back to the fundamental; a separating filter (24), coupled to the AC output, for separating the fundamental and that at least one harmonic; at least one converter (30 and 32), coupled to the at least one harmonic from the converter and to the controller, each converter being switched by control signals from the controller which have a calculated switching frequency for transforming at least one of the at least one harmonic to the fundamental; and outputs from the at least one converter being combined with the fundamental from the separating filter.

Holographic Optical Element with Analyzer Function for Magneto-Optical Disk Head

Abstract: A new holographic optical element, made of a birefringent LiNbO3 substrate, has been developed for magneto-optical, disk heads. The element includes the analyzer function required for magneto-optical signal detection, in addition to focusing and tracking error signal detection functions. The analyzer function was realized by introducing a birefringent grating structure, using proton exchange method. More than 15dB extinction ratios were obtained for the fabricated element.

Spectrum analyzer having functions for simultaneously executing plural kinds of detections and displaying resultants thereof

Abstract: A frequency conversion section sweeps an object signal within a desired measurement frequency range, thereby frequency-converting the object signal. A peak detector detects a peak of an output from the frequency converting section. A measurement detector measures and detects the output from the frequency conversion section simultaneously with the peak detection by the peak detector. The measurement detector has an output characteristic lower than an output characteristic of the peak detector. A display displays an output from the peak detector and an output from the measurement detector on a single display screen, in synchronism with the sweeping by the frequency conversion section, with these outputs of the peak detector and the measurement detector being plotted along an axis representative of frequencies. In another mode of the invention, an alarm device indicates the fact that an output from the peak detector has exceeded a predetermined allowable limit level.

Pattern matching vocoder using LSP parameters

Abstract: The system utilizes a linear predictive coding (LPC) analyzer, an Attenuator, a line spectrum pair (LSP) analyzer, a reference pattern memory and a pattern matching device The LPC analyzer derives LPC parameters from an input speech signal The LPC parameters are attenuated in the attenuator and fed to the LSP analyzer for deriving LSP parameters which are in turn fed to the pattern matching device The reference pattern memory stores a plurality of reference patterns composed of a sequence of LSP parameters for a variety of predetermined speech samples The pattern matching device is connected to the LSP analyzer and the reference pattern memory to select the reference pattern which most closely resembles the input pattern from the LSP analyzer and to provide a label code as an output thereof On the decoding side, a decoder is responsive to the label for generating LPC parameters corresponding to the reference pattern of the label A residual signal which is also transmitted with the reference label is received and fed with the generated LPC parameters to a synthesis filter for providing a synthesized speech signal which is subsequently converted into an analog signal

Interferometric acousto-optic spectrum analyzer

Abstract: An interferometric spectrum analyzer employs a pair of Bragg cells arranged in an optically cascaded configuration such that both the signal beam and the reference beam travel along a common optical path. The beam-modifying properties of the Bragg cells are such that within a prescribed bandwidth of operation, the deflection properties of the respective cells are frequency complementary, namely different frequencies applied to the respective cells deflect the beam passing therethrough along the same optical path, to produce a beat frequency at the Fourier transform plane. In accordance with a first embodiment, complementary deflection action is achieved by using Bragg cells having respectively different acoustic velocites. In a second embodiment, each Bragg cell has the same acoustic velocity. The deflection/frequency complementary effect is obtained by the use of a birefringent material prism interposed between the Bragg cells, which produces angular deviation that depends upon the polarization and the direction of propagation of light passing through the prism.

Anesthetic agent identification analyzer and contamination detector

Abstract: A gaz analyzer for measuring the transmission of infrared radiation through a gas mixture, determining the concentrations of the gases in the mixture, identifying one of the gases, reporting the concentration of the identified gas, and detecting contamination of the gas The gas analyzer has a sample cell (21) for containing the gas mixture, source of infrared radiation (11), a set of specifically chosen filters, a signal processor (24), and a microprocessor (59) that computes the concentrations of the gases and implements decision logic for identifying one gas and detecting contamination of that gas In one embodiment, a filter wheel (17) holds the filters between the source and the sample cell and there is a single detector placed downstream from the sample cell In a second embodiment, a chopper produces an AC signal from the infrared radiation source and there are three filters, one in front of each of three detectors An alternate embodiment measures, calculates, and reports the concentrations of three anesthetizing agents

A Wigner spectral analyzer for nonstationary signals

Abstract: The authors present computational algorithms for the design of an innovative spectral analyzer using the Wigner distribution. This spectral analyzer uses advanced digital signal-processing chips with associated hardware and software. Algorithms for the kernel generation, kernel transformation, and discrete Hilbert transform are discussed. Design strategies are focused on achieving high time-frequency resolution, precision, flexibility, and computational efficiency. Experiments show that spectral analysis using the Wigner distribution yields significantly improved results for nonstationary signals. >

Continuous Infrared Analysis Of N2O in combustion products

Abstract: Nitrous oxide (N2O) levels in the atmosphere are increasing, potentially contributing to the greenhouse effect and depletion of stratospheric ozone. From a limited data base, combustion sources have been identified as a major anthropogenic source of N2O. However, the existing data base (obtained by traditional grab sampling techniques followed by gas chromatographic analysis) is in question due to the discovery of a sampling artifact. A continuous on-line N2O analyzer would enable and facilitate the accurate characterization of combustion sources over a range of operating conditions, and also aid in the development of an appropriate sampling technique. This paper addresses the development of a continuous measurement technique, and the evaluation and initial use of a field prototype continuous N2O analyzer developed at the UCI Combustion Laboratory in cooperation with a major instrument manufacturer. The analyzer is capable of measuring N2O levels down to a few ppm. The analyzer has been evaluated and used...

Multichannel detection high‐resolution electron energy loss spectrometer

Abstract: A new general‐purpose high‐resolution electron energy loss spectrometer has been constructed and tested. Novel features of the electron optics include multichannel energy detection and tandem four‐element zoom lenses that incorporate beam defining apertures. Compact design of the lenses permit scattering measurements in which the total scattering angle is less than 40°. This feature permits probing bulk phonon modes. The lens system permits electronic adjustment of the analyzer collection angle, and yields high transmission at retardation/acceleration ratios of 400:1. Performance characteristics include simultaneous detection of 50 energy channels at 4‐meV energy resolution and target currents exceeding 2×10−10 A. Separate monochromator and analyzer goniometers permit access to out‐of‐plane scattering configurations which enables probing odd symmetry shear surface modes.

Spectral analysis, digital integration, and measurement of low backscatter in coherent laser radar

Abstract: The operation of a surface acoustic wave spectrum analyser and digital integrator is reviewed. Expressions are derived for signal to noise ratio in the measured voltage spectrum with an approximation for the general case and rigorous treatment for the low signal case. A previous calibration study is re-evaluated to provide a final calibration for the atmospheric backscatter data accumulated by the airborne LATAS (laser true airspeed) coherent laser radar system.