Showing papers on "Spectrum analyzer published in 1980"

The Pioneer Venus Orbiter Plasma Analyzer Experiment

Abstract: The plasma analyzer experiment on the Pioneer Venus Orbiter was designed to determine the basic characteristics of the plasma environment of Venus and the nature of the solar wind interaction at Venus. The plasma analyzer experiment is an electrostatic energy-per-unit charge (E/Q) spectrometer which measures ions and electrons. There is a curved plate electrostatic analyzer system with multiple collectors. The experiment obtains the three dimensional plasma distribution function. Some of the scientific objectives of the instrument are briefly discussed, the general characteristics of the experiment are summarized, and some of the analyses based on the data are presented.

Passive remote temperature sensor system.

Abstract: Passive non-invasive temperature measurement of the interior of a body is accomplished by using the acoustic thermal noise spectra of the body. One or more acoustic transducers are coupled with the surface of the body to intercept the acoustical noise signal from within the interior of the body along well defined paths to generate a corresponding electrical signal. The noise power spectrum of the electrical signal is analyzed by means of a power spectrum analyzer to develop an output representing the temperature-depth distribution along said paths. The output of the power spectrum analyzer may be displayed and/or recorded or subjected to further signal processing.

Theory for broadband detection of ion cyclotron resonance signals

Abstract: A complete line shape theory is developed for the transient response of a new type of ion cyclotron resonance (ICR) detector circuit. The detector is basically a balanced capacitance bridge which is sensitive to the abundance of gaseous ions stored in a static magnetic ion trap. For the first time, the equations of motion of ions in the ICR analyzer cell are shown to be coupled to the circuit equations of the detector. Also, the effect of nonreactive ion–molecule collisions on line shapes and on the transient response of the detector are analyzed and shown to allow measurement of ion–molecule collisions frequencies as a function of ion translational energy. One of the most important features of the capacitance bridge detector is its broadband sensitivity to a wide range of ion cyclotron resonance frequencies. This allows a mass spectrum of ions stored in the ICR analyzer cell to be obtained by scanning the frequency ω1 of the irradiating rf electric field at a fixed magnetic field strength. The capacitanc...

Optimization of the trochoidal electron monochromator

Abstract: The trochoidal electron monochromator employs an axial magnetic field and a transverse electric field. Many aspects of its performance can be described by electron trajectory equations which include the voltage drop across the entrance aperture. A beam shear is predicted, which is a function of a parameter tanϑ. Optimum performance is achieved by matching the exit aperture to the sheared beam. tanϑ establishes a relationship between the field magnitudes and the dimensions of the monochromator. Estimates of appropriate values for these parameters can be made, with the final optimum values being determined by a combination of practical and empirical considerations. Finally, the use of the instrument as an energy analyzer is described.

Method and apparatus for engine exhaust analyzer

Abstract: A processing unit for normalizing the output data of a gas analyzer in view of zero adjustment data and gain adjustment data formulated by the processing unit controlling air input and span reference simulation of a reference gas. A voltage reference generator is manually variable for calibrating the system while passing a known reference gas through the analyzer, in order to provide a scaling factor for use during output data adjustment. A hold switch is manually actuable by the operator for storing in memory the value of a gas analyzation voltage for permitting adjustment to the output data after the gas is removed from the cell of the analyzer.

Integrated Optic Spectrum Analyzer

Abstract: This paper describes the integrated-optic implementation of a Bragg spectrum analyzer that employs the interaction between a coherent optical guided wave and a surface acoustic wave to determine the power spectral density of the input. The integrated-optic spectrum analyzer consists of an injection laser diode, a thin-film optical waveguide, waveguide lenses, a surface-acoustic-wave transducer, and a linear detector array with CCD readout. Design principles are given for selecting component parameters such as optical beam width, detector cell size, lens aperture and focal length, and acoustic transducer design so as to obtain specific rf resolution, spurious level, and signal-to-noise ratio. Design parameters are presented for a 750- to 1250-MHz spectrum analyzer with a resolution of 4 MHz and a 40-dB dynamic range. Also described in the paper is the development of state-of-the-art component technology for the spectrum analyzer.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

High speed laser pulse analyzer

Abstract: Apparatus, including a detector array, analog-to-digital converter, a microprocessor including a memory, and display for determining the total energy, divergence and position of an applied laser beam from a single laser pulse. The detector array is coupled to the microprocessor and computer memory by way of the analog-to-digital converter. The microprocessor controls the detector array scanning and computes the values for the desired characteristics. The display provides for a numerical, alpha-numerical or printed record of the calculated values. A method of determining the total energy, relative position and divergence is also provided.

Mechanical vibration analyzer

Abstract: A visual graphical display of instantaneous mechanical vibration versus frequency over a selected frequency spectrum is presented to provide a vibration analyst with a prompt overall visual impression of the mechanical vibration characteristics of a rotating device which is under surveillance. In an alternative application, the visual display permits a rapid adjustment of an electrical bandpass filter of an associated vibration analyzer. The device employs several trains of diodes which are arranged so that one or more diode in each train is illuminated at any one moment.

Method of and apparatus for measuring optical frequency variations

Abstract: Herein is disclosed a method of and apparatus for measuring optical frequency variations wherein linearly-polarized incident light generated by a tunable laser or the like is delivered to a passive resonant cavity incorporating a linear polarizer such as a Brewster plate so that the reflected light acquires a frequency-dependent elliptical polarization which can be detected by a simple polarization analyzer providing a signal correlated with the frequency variation of the laser. Such signal can be utilized as a feedback error signal to stabilize the laser frequency, or to adjust the cavity resonance. If the cavity is tunable, tuning thereof will in turn provide a precision method for tuning of the laser itself.

Field portable element analysis unit

Abstract: A field portable X-ray fluorescent spectrometer is described including a multichannel analyzer (2) and a plurality of interchangeable sensor heads (4). Each sensor head includes a shutter (100) which, when open, permits one of several radiation sources (80, 82) to irradiate a material to be analyzed. The returned radiation is detected by a corresponding detector (86, 90), which provides corresponding data in response. This shutter has calibration plaques attached to it so that, when closed, the plaques are exposed to the radiation sources and return radiation having selected energy distributions to the detectors. The multichannel analyzer uses the resulting detector data to calibrate the sensor head. Each sensor head includes circuitry (290) for identifying itself to the multichannel analyzer. The analyzer automatically adapts its operation in accordance with this identification. When the shutter is open, the multichannel analyzer utilizes the detector data to accumulate an energy spectrum of the material being analyzed, and displays the spectrum on a display screen (12). A cursor control (28) allows the operator to move a cursor along the displayed spectrum. A display (32) is automatically provided with a display of the symbol of the element, if any, having its major spectral peak at the position identified by the cursor. Secondary indications identify other positions along the spectrum at which peaks would appear if the element were present. Memory (202) is provided for storing a number of reference spectra, any of one of which may be displayed on the screen along with the acquired spectrum for comparison purposes. The memory (202) also stores previously acquired spectra for later analysis. The analyzer also includes other operational features, such as normalization, window control, and ratio and concentration determination, to permit the operator to quantitatively analyze materials in the field.

Spectrum analyzer with frequency band selection

Abstract: A spectrum analyzer for FFT analyzing and displaying the frequency spectrum of a digital signal over a given frequency band (background), as well as over a more limited frequency band (foreground). The spectrum of the signal over each frequency band is calculated and displayed so as to appear on a screen as a simultaneous display. The position of the limited frequency band as well as the width thereof, may be varied.

Real-Time Spectrum Analysis and Display of Directional Doppler Ultrasound Blood Velocity Signals

Abstract: Development of a real-time system for three-dimensional display of Doppler shifted frequencies within an ultrasound flowmeter signal is described. The device is based on a fast Fourier transform (FFT) spectrum analyzer which provides both high frequency and time resolution over a variable range of frequencies up to 40 kHz. Signal preprocessing filters unwanted low frequency artifacts due to arterial wail motion and automatically controls input gain to limit peak amplitudes while matched phase shift networks translate forward and reverse components for a directional output. A digital first moment is calculated and the display may be viewed in a continuous or freeze frame mode. Clinical applications underway have shown improved detail and accuracy in the use of ultrasound for diagnosing various vascular abnormalities.

Gas analyzer calibration apparatus

Abstract: A gas analyzer calibration apparatus. The apparatus operably connects between a monitored gaseous environment and a gas analyzer. The apparatus includes a vacuum pump for drawing test gases from the monitored environment through the apparatus and through the analyzer. A fluidic gate selectively allows or impedes the flow of test gases to the analyzer and provides calibration gases to the analyzer at the analyzer's demand rate, and may be heated to prevent the condensation of hot test gases flowing therethrough. The fluidic gate will pass both span calibration gases and zero calibration gases, as desired. A vacuum breaker provides atmospheric gases for use as a zero calibration gas.

Composite logic analyzer capable of data display in two time-related formats

Abstract: A combined logic timing and state analyzer comprises an internally clocked, timing analyzer section receiving a first set of logic signals, and an externally clocked, state analyzer section receiving a second set of logic signals. The timing analyzer section samples the first set of logic signals, as well as the external clock signal associated with the second set of logic signals, at a rate determined by the internal clock pulses and stores the samples in a first set of memories. The state analyzer section samples the second set of logic signals at a rate determined by the external clock pulses and stores the samples in a second set of memories. Data introduction into the memories terminates when they are triggered, as in the event of a malfunction of the system being investigated. The logic analyzer further includes a display circuit for repetitively reading out the first and the second sets of memories and for causing a display device to visually present the output data of the first memory set in the form of a timing diagram and the output data of the second memory set in the form of a state table. The time relationship between the two display formats can be readily ascertained since the timing diagram includes a waveform, or other visual representations, indicative of the external clock pulses used for sampling the second set of logic signals.

Method of and device for testing the quality of digital speech-transmission equipment

Abstract: A device for analyzing the quality of digital speech-transmission equipment, specifically a speech coder, comprises generators of white-noise signals, sinusoidal signals, frequency-shaped signals and artificial speech-like signals connected to the coder and to an adaptive transversal filter in parallel therewith. The filter and the coder feed output signals to a subtractor which produces an error or noise signal by deducting digital samples of the filter output signal from corresponding samples of the coder output signal. The error signal is fed back to the filter during a first testing phase to control the periodic modification of weighting coefficients computed by a multiplicity of updating cells in the filter for multiplicative combination with incoming samples of the test signal. The first phase ends when the coefficients converge to fixed values representative of the linear characteristics of the coder and the error signal assumes a substantially constant near-zero level. In a second testing phase the error signal from the subtractor and the corrected output signal of the filter are fed to a quality analyzer which calculates one or more parameters from a set comprising a total signal-to-noise ratio, a simple segmental signal-to-noise ratio and a frequency-weighted segmental signal-to-noise ratio, the parameters being linearly combined to produce an integer between zero and ten indicative of the transmission quality of the coder.

Digitally compatible optical pressure measurement

Abstract: An apparatus for pressure measurement employs fiber optics to transport a broadband beam light to and from a remote electrically passive sensing head. In the sensing head, a linearly polarized beam is phase shifted in a birefringent plate, then passed through a photoelastic pressure sensor and a polarization analyzer. The wavelength for which the output light has an intensity minimum is a measure of the applied pressure.

Distortion measurement system

Abstract: A type of Total-Harmonic-Distortion (THD) distortion analyzer is described in which the use of the State Variable (SV) circuit in both the oscillator and the filter sections confers several benefits and results in performance superior to previously available analyzers. In the SV oscillator, the traditional compromise in the automatic level control function between settling time, component tolerance and distortion is alleviated by the use of polyphase level detection, made possible by the SV circuit. The doubly-integrated output available from the SV circuit also minimizes distortion, especially that contributed by the level-setting AGC. The other property of the SV circuit, which is particularly valuable, is the connection of frequency-setting elements to virtual-ground points, which allows great simplification of wide-range tuning circuitry. Exploitation of this property is described both for manual and programmable cases. The SV circuit is also superior to many previously employed circuits in its tolerance of component inaccuracies. The simultaneous presence of high-pass, band-pass and low-pass outputs from the SV filter is shown to be advantageous also for its use as the filter on a distortion analyzer.

Automatic note analyzer

Abstract: An automatic note analyzer is disclosed which automatically generates and displays a note signal indicative of the musical note corresponding to an input signal. The disclosed analyzer operates to measure the period of the input signal on a regular basis. According to one aspect of the invention, the measured period is compared with a predetermined window representative of the expected value of the measured period. Measured periods which do not fall within the predetermined window are rejected. According to a second feature, measured signals representative of the period of the input signal are averaged in order to increase the stability of the analyzer. The disclosed analyzer operates in two modes: an absolute mode, and a transposer mode. In the absolute mode the displayed note value is determined with reference to an absolute pitch. In the transposer mode, the displayed note value is determined with reference to a relative pitch which can be readily adjusted as needed.

Flame photometric detector analyzer

Abstract: A flame detector analyzer of the type wherein a sample gas is introduced into a flame formed by burning a fuel gas in presence of a combustion supporting gas, comprises a background providing device for supplying a background component gas capable of emitting a characteristic spectrum having the same wave length as that of the characteristic spectrum of a measuring object component contained in the sample gas, the light spectrums emitted from the measuring object component and the background component gas being received and treated to be detected, thereby increasing the measuring accuracy for the measuring object component and improving the resolving power at a low concentration detection region.

Application of ion implantation to LiNbO3 integrated, optical spectrum analyzers

Abstract: A method of improving the signal-to-noise ratio (dynamic range) in integrated optical spectrum analyzers. An integrated optical spectrum analyzer is formed with a lithium niobate (LiNbO3) substrate in its usual manner. Ions such as argon or hydrogen are implanted in the bottom and sides of the LiNbO3 which causes the substrate to absorb light at the wavelength of interest. The ion-implanted bottom and sides provide absorption with very little reflectivity and the amount of absorption is proportional to the effect of the ion and the time period of implantation. The bottom and sides behave as optical sinks, rather than as reflection or scattering centers.

Method and apparatus for the simultaneous measurement of data, including velocity, relating to submicronic particles in a state of flow in a fluid

Abstract: The same assembly is used to first record the homodyne spectrum from the light diffused from a single beam FL 2 , with a mask D 1 masking the beam FL 1 . On the passage of a critical frequency f c , mask D 1 is removed, the aperture of a diaphragm D 2 is reduced, and the heterodyne spectrum produced by FL 1 and FL 2 is recorded as received by a photomultiplier PM and a spectrum analyzer AS.

A New Ultra Small Battery Operated Portable Multi-Channel Analyzer

Abstract: A newly designed portable multi-channel analyzer (MCA) has been developed at Los Alamos that has much improved physical and performance characteristics over previous designs. Namely, the instrument is very compact (25 cm wide × 14 cm deep × 21 cm high) and has a mass of 4.2 Kg (9.2 lb). The device has 1024 channels and is microprocessor controlled. The instrument has most of the standard features of present laboratory-based pulse height analyzers, including CRT display, region of interest integration, etc. Battery life of the MCA is nearly eight hours, with full charging over night. An accessory case carries a small audio cassette recorder for data storage. The case also contains two different NaI (Tl) detectors. Another case contains a 10% efficient hyperpure germanium (HpGe) detector for very high energy resolution gamuna ray spectroscopy. That detector (commercially available) is portable and can carry enough liquid nitrogen for 10 hours of field use. All necessary electronics to acquire data from the various detectors are located on the detectors themselves. No additional power supplies, NIM equipment, etc., are necessary for field operation.

Low energy H atom analyzer using a cesium heat pipe

Abstract: The efficiency of detecting H and D atoms (E<1 keV) escaping a plasma has been increased by use of a cesium vapor cell to form negative ions by electron attachment collisions. A 30 cm long heat pipe confines the cesium to a localized region. The resulting negative ions are energy analyzed with a single‐channel, parabolic parallel‐plate analyzer and detected by a channel multiplier. The H0 conversion efficiency was 10−2 at 100 eV, increasing to 3.8×10−2 at 500 eV. For a H0 energy of 100 eV, the analyzer is 2.5 orders of magnitude more efficient than a comparable N2 stripping cell analyzer. The analyzer has been used to measure ion temperatures as low as 30 eV on the EBT Plasma experiment.