Showing papers on "Spectrum analyzer published in 1971"

A Wien Filter for Use as an Energy Analyzer with an Electron Microscope

Abstract: An electron optical system is described which is suitable for energy loss analysis in an electron microscope. A focusing spectrometer of the Wien type has been added underneath the column of a Hitachi HU11A electron microscope. After passing through the microscope, the electrons are slowed down before entering the spectrometer and reaccelerated to the detection point. Appropriate control of the electron trajectories into the Wien analyzer is achieved with a quadrupole field lens which makes it possible to use a long entrance slit. The energy resolution of the analyzer is limited by the width of the entrance slit which is adjusted to match the beam spread (1.5 eV). It can be made large (250 μ) compared with that of the Mollenstedt analyzer (5 μ), thereby passing much higher intensity through the analyzer and increasing the system flexibility.

Method and apparatus for testing the condition of a machine

Abstract: The vibrational components over a frequency spectrum of interest developed by a machine are transformed into electrical signals by means of a transducer such as an accelerometer, and these electrical signals in turn are processed by means of a spectrum analyzer to provide a power spectral density plot thereof. The peak amplitude of the signals in a pair of preselected frequency bands is then detected and the ratio between these two signals determined. This ratio is then compared against a value representing an acceptable ratio experimentally or theoretically derived to determine whether the measured ratio is within acceptable tolerances for the machine. The bands utilized are preferably a first band within a high frequency vibrational range, and a second band lower in frequency than this first band with the signals in these bands being of medium amplitude relative to all of the signals developed in the spectral analysis.

Analyzer employing magneto-optic rotation

Abstract: A magneto-optic rotation analyzer method and apparatus is disclosed. In the analyzer, a light beam of linearly polarized light, preferably in the ultra-violet region is shown through a sample of a material to be analyzed. A magnetic field is applied to the sample parallel to the light beam to obtain magneto-optic rotation of the polarization of the light by constituents of the sample. The emerging light beam is analyzed as to its polarization to separate light which is rotated from light which has not been rotated. One of the separated light beams is detected by a photodetector. The magneto-optic rotation effect is modulated at a certain modulation frequency and the output signal is synchronously detected against the modulation frequency or a harmonic thereof for improved signal-to-noise ratio. The synchronously detected output is measured to obtain a measurement of the sample under analysis.

Photometric analyzer sampling cell

Abstract: A movable window which coacts with a fixed window in an on-stream photometric analyzer for trapping a sample of flowing fluid for analysis without interrupting the flow of the main stream. The two windows comprise a sample cell when in close proximity to one another. After the analysis, the movable window is retracted so that the sample is released and residues purged by the main stream before the process is repeated.

Calibration system for gas analyzers

Abstract: Purified air is mixed with a source gas generated by a permeation tube to form a mixture of precise concentration The mixture is used for calibrating a gas analyzer Solenoid actuated valves selectively furnish the analyzer with either one gas, or a plurality of gases simultaneously Means within the invention system maintain the gases delivered to an analyzer at constant humidity and temperature to insure reproducibility of calibration results

Method for the detection of radar targets

Abstract: Method and apparatus for detecting targets in high sea states and sea clutter. A comparison is made of a stored representation of doppler spectrums from sea returns free of targets with instantaneous statistics of sea clutter doppler to determine the presence of a target. Radar return pulses are fed through range gates and filters to produce a spectrum of signals corresponding to distributed ranges from the radar. The spectrum of signals is compared with the stored doppler spectrum in a variance analyzer to produce an output when a target signal is present.

Pcm system including a pulse pattern analyzer

Abstract: A delta pulse code modulation system includes a feedback loop comprising a pulse pattern analyzer for detecting a large instantaneous modulation index within a fixed time interval. The system exhibits a wide range of modulation and suppresses whistling and interference tones at low pulse rates.

Increased Rate of Analysis by Use of a 42-Cuvet GeMSAEC1 Fast Analyzer

Abstract: Sample analysis rate for a GeMSAEC Fast Analyzer is directly proportional to the number of sample cuvets contained in each rotor. GeMSAEC Fast Analyzers are available having either 15-, 16-, or 30-place rotors. To increase the sample analysis rate, an advanced GeMSAEC Fast Analyzer has been designed and fabricated that uses a 42-place rotor. The 42-place rotor, in order to accommodate the increased number of cuvets, is a modified enlargement of the previously described 15-place rotor [N. G. Anderson, Science 166, 317(1969)]. The hardware of the 42-place system is fully compatible with the existing GeMSAEC computer module, and existing software used in the 15-place system has been modified for use with the 42-place system. Results obtained for various chemical and enzymatic analyses are discussed.

Methods of Measuring the Performance of an Electrostatic Spectrometer

Abstract: The methods used to measure response and performances of an electrostatic spectrometer with an identical apparatus are studied in the case of the 127° cylindrical spectrometer by means of a method of calculation of the electron energy distribution. The distribution given by the monochromator is calculated and its analysis with the identical analyzer is simulated. The three usual methods of analysis are found to give inaccurate results not only for the widths of the energy distribution but also for its profile. It is shown that because of the inherent angular dispersion of the analyzer, it is necessary to carry out the analysis of the beam by narrow angular slices in order to recover the exact profile of the energy distribution yielded by the monochromator.

The Spectrum Analyzer Applied to the Measurement of EHV Power Line Radio Noise

Abstract: In order to reduce time and improve the quality of measurements* of EHV power line radio noise, the use of spectrum analyzers and X-Y recording techniques with radio noise meters was investigated. Comparisons were made with the usual manual readings taken simultaneously from radio noise meters used as the standard measuring instruments. With the spectrum analyzer, measurements of radio noise from conductor corona both in rain and fair weather conditions were made in the 1 MHz frequency region. In addition, the interference from a gap-type source was successfully measured over a frequency range from 10 kHz to 1 GHz.

Single path,dual source radiant energy analyzer

Abstract: There is disclosed a radiant energy analyzer having a primary and secondary source of radiant energy which energy traverses a partially coincident path to a radiant energy detector. The primary source issues a radiant energy spectrum which is coincident at least in part with the absorption spectrum of a substance being analyzed. The secondary source generates a reference spectrum of radiant energy to which the spectrum from the primary source is compared in the radiant energy detector. The sources are alternately activated to provide a sample or measurement condition and a reference condition for analysis. The primary source is always directed through a container which confines the substance being analyzed and finally to the detector. The secondary source may be interposed between the container and the primary source, between the container and the detector or optically combined in parallel with the primary source depending upon the secondary source''s spectrum of radiation and the analyzer application. A feedback loop is provided from the detector to at least one of the sources to control the radiant energy therefrom whereby the measurement and reference conditions are maintained balanced.

Oil contamination monitor with digital signal processing

Abstract: The circuit for digitally processing the analog signals from an oil contamination monitor includes analog to digital converters, digital accumulators for accumulating the thus converted signals over a predetermined period of time and digital comparators, preferably dividers for forming ratios of the thus accumulated digital signals to produce a comparison output. When a single analog signal corresponding to the light scattering effect a reference material and the oil to be monitored have upon light is to be processed, gate means first separates the analog signal corresponding to only the light scattering effect of the oil and a second analog signal corresponding only to the light scattering effect of the reference material; and when a single analog electrical signal corresponding to the light attenuation effect the reference material and oil have upon light is to be processed, gate means separates the single signal into a first analog signal corresponding only to the light attenuation effect of the oil and a second analog signal corresponding only to the light attenuation affect of the reference material. Each of the thus separated analog signals is processed by an analog to digital converter whose output is accumulated over a predetermined period of time and fed to a respective one of two digital dividers, with the first digital having an output corresponding to the ratio of the light scattering effect of the oil and the light scattering effect of the reference, and the second digital divider having an output corresponding to the light transmission effect of the oil and the light transmission effect of the reference material. The ratio output of the first digital divider is fed directly to the digital analyzer while the ratio output of the second digital divider, corresponding to light transmission, is first fed to a digital subtractor where it is subtracted from a predetermined higher digital standard corresponding to complete light transmission so as to produce an attenuation ratio output that is fed directly to the digital analyzer. The digital analyzer may give representative values to the amount of contamination within the oil or the chemical breakdown or the like of the oil, or have warning lights as to excessive contamination or oil breakdown.

Infrared two gas analyzer

Abstract: A radiation absorption analyzer is disclosed for the measurement of two gases in a gas sample being analyzed utilizing the same equipment, and for simultaneous measurement of the two gases with some duplication in the electronic processing. A source of infrared radiation is applied through a sample or absorption cell containing the gas to be measured, and through a rotating optical filter wheel onto an infrared detector. The filter wheel contains two analytic filters passing absorption regions of the gases desired to be measured, and two reference filters in nonabsorbing regions. Two reference pickups are utilized, which generate two signals as the filter wheel rotates, which are out of phase with each other by 90*. The signals from the detector and from the reference pickups are fed to a synchronous rectifier which rejects signals 90* out of phase with the reference signal, thereby providing a rectified output representing the quantity of gas in the sample cell under test. A switch may be utilized to apply the reference signals to a single synchronous rectifier, or a separate synchronous rectifier and meter may be utilized, with the reference pickups applied one to each channel for providing simultaneous two-gas analysis. The two-gas analyzer is provided with aperture trimming to radiometrically balance each analytic filter with respect to its reference filter. The two-gas analyzer is suitable for the measurement of auto emissions from the tail pipe of a car for use in inspection stations, garages, etc.

Optical current transformer

Abstract: An optical current transformer in which two light beams coming from the same source successively pass through: (1) a first polarizer, a first material having a magnetic rotational power influenced by the electrical current to be measured and a first analyzer, to end up on a photoelectric detector; and (2) a second polarizer, a second material having a magnetic rotational power influenced by a measuring electrical current and a second analyzer, to end up on the same photoelectric detector. The measuring current is dependent on the detector for maintaining a constant flux on the latter. The angle between the polarization planes of the polarizers and the analyzers of each pair is 45*.

System for the transmission of multilevel data signals

Abstract: A system for the transmission of multilevel data signals in which a multilevel coder incorporated in the transmitter includes a pulse group analyzer which is provided with m output lines which analyses pulse groups each containing k binary pulses of the binary information signals, and applies a pulse series characteristic of the analyzed pulse group to each output line which pulses are applied through a cascade arrangement of amplitude control device and pseudo-ternary code converter incorporated in each output line to a combination device from whose output a 2m + 1 level signal is derived at a frequency spectrum in which spectral zeros occur at prescribed positions. In the receiver this signal is applied to a cascade arrangement of a full-wave rectifier and a level separator including m output lines which are applied to a pulse group shaper with which the original information signals are uniformly recovered.

A Plane Electrostatic Analyzer for Laser Produced Plasma Studies

Abstract: The use of an electrostatic analyzer as a time‐of‐flight spectrometer for studying laser produced plasmas is discussed. It is shown that a plane electrostatic analyzer, accommodating several detectors simultaneously, can be used to determine several points on the velocity distribution curve for the ions produced upon irradiation of a target with a single Q‐switched laser pulse. This minimizes the problem of shot‐to‐shot reproducibility of the laser. It is shown also that with a 30° plane analyzer good energy and time resolution are obtainable in determining the time dependent ion velocity distribution for a laser produced plasma.

Magneto-optic rotation analyzer

Abstract: In a magneto-optic rotation analyzer, a first modulator modulates the magneto-optic rotation, if any, of the probing light beam by the sample at a first modulation frequency and a second reference modulator, independent of the sample, modulates the polarization of the probing light beam at a second reference modulation frequency. Both modulators produce separate modulation components in the output of the photo-multiplier employed to detect the polarization affected probing light beam. The separate sample and reference modulation signal components are separately detected and integrated. The reference signal is utilized to compensate for variations in the parameters of the optical components through the optical path of the analyzer.

Optical autocorrelator signal processor

Abstract: A correlation receiver for detecting and measuring the angle-of-arrival ofadio frequency signals, including two antennas, a correlation processor, and a CRT display

Spurious signals and intermodulation products detection enhancement circuit

Abstract: A test system where a fundamental signal is sent through a unit to be tested and at the same time this signal is sent around said unit to be tested and shifted a 180* in phase with respect to output of unit. The two signals are then combined to eliminate the fundamental, and the spurious signal is measured by a spectrum analyzer.

Infrared gas analyzer

Abstract: The analyzer comprises, in succession, an infrared ray source, a modulator, an analysis chamber containing the mixture of gasses, and a detector together with associated electronic circuits for processing the electric signals delivered by the detector. The modulator periodically interposes in the path of the radiation of gaseous reference filter which absorbs the characteristic lines of the particular gas to be analyzed, and a measurement filter which does not absorb these lines. The filters are separated from each other by two identical base filters comprising an element permitting grey transmission slightly lower than the average transmission of the reference filter so that the detector delivers successively a measurement signal and a reference signal respectively defined with respect to a common level determined by the base filters. The electronic processing circuits comprise means for amplifying and demultiplexing the signals and means for establishing and reading out the quotient of the measurement signal and the reference signal. This quotient is representative of only the concentration sought.

Defibrillator output energy measuring circuit

Abstract: A universal portable analyzer for defibrillators giving a direct readout, in watt-seconds, of electrical energy pulses regardless of wave shape and polarity. A voltage divider input attenuates the signal and feeds it through gain and buffer stages. A zero crossing detector gates switching networks for sequentially passing positive and negative signal components respectively to separate integrators which generate outputs proportional to the total positive and negative current of the input pulse. These outputs are stretched so that they occur simultaneously, are added together and squared to provide a signal porportional to power which is applied to a watt-second meter for direct readout. The solid state circuits include automatic ON-OFF control, and automatic zero reset at the beginning of each test cycle makes analyzer suited for use by non-technical personnel.

Apparatus for correlation spectroscopy

Abstract: Arrangement for correlation spectroscopy by means of the absorption or emission spectrum of a gas. Light from the gas is arranged to be fed to an analyzer, comprising a light transmitting disc arranged in front of a detector. One side of the disc is supplied with an interference filter which within at least one segment of the filter has transmission characteristics as a function of the wavelength within a determined range of wavelengths. The range of wavelengths corresponds to the absorption or emission spectrum of a searched ingredient in the gas. The other parts of said filter have different transmission characteristics. These parts have different transmission characteristics relative to one another and are arranged to be alternatively inserted into the beam path in front of the detector.

Method and means for providing resolution level selection in a spectrum analyzer

Abstract: Resolution level selection in a spectrum analyzer is provided by digitizing the IF analog input signal at a controllable rate, storing it in a digital memory device, and reading out the stored digital signal at an increased rate into a digital-to-analog converter. The resolution level is determined by the relationship between the digitizing rate and the memory read out rate.

Automatic Photoelastimeter for Determining Very Small Dilatations

Abstract: A sensitivity of 0.03-mμ birefringence is achieved by the introduction of a plastic disk (~6-mμ birefringence) rotated at 30 Hz to modulate the birefringence at 60 Hz and a suitable detector. Two components are found in the detector signal: the one (120 Hz) that depends on the modulator birefringence is rejected; the other (60 Hz) which depends linearly on the compensator birefringence and changes phase at extinction is utilized. An A.E.I. BTH compact mercury arc (with interference filter for 546 mμ) operated on dc is the light source; a photomultiplier 1P21 is the detector. The signal is first fed into a parallel T notch filter which reduces the 120-Hz component five-hundred-fold and then into a three-stage narrow-band (5-Hz) active filter (utilizing three integrated-circuit operational amplifiers) that provides possible gain of 151 dB for the 60-Hz component. To obviate tedious manual setting of the compensator for the required traverse of the specimen, a 60-Hz servo motor is linked to the tangent screw of the analyzer and operated by a power amplifier for the active filter-output signal. Potentiometers on the specimen-translation screw and on the analyzer tangent screw permit the data to be plotted on an x-y For vitreous silica specimens 1 cm deep, 3 mm wide, irradiated with electrons of 1-mm range recorder. (0.6 MeV), the effect of a radiation-induced dilatation as small as 3 × 10−8 can be observed, equivalent to inserting an atomic sheet into a 1-cm long specimen. Alternatively, 1% dilatation of a surface layer 30 A thick can be detected.

Computer-Coupled Ge(Li) Spectroscopy in Neutron Activation Analysis of Semiconductor Silicon

Abstract: The spectrometer system developed in this work consists of a Ge(Li) detector and a 4096-channel multichannel analyzer interfaced directly to a computer with 16,384 24-bit words. The restrictions imposed by a medium-sized core have been circumvented by performing the data reduction in successive steps which are called from a disk file while the data remain in core. Since the analyzer memory is not used to store data during reduction, new data can be acquired while data reduction is in progress. The disk file includes routines for energy calibration, efficiency calibration for each of the geometries used in counting, smoothing, and peak location and integration. The output options include linear or semilogarithmic plots of the spectra. Calibration in the energy region 40-1600 keV is done with a mixed source 57Co, 137Cs, and 60Co. Since the samples are routinely irradiated under reproducible conditions in the same reactor, the flux can be derived from a single flux value obtained from a gold and cobalt monit...

An Electron Energy Analyzer for Photoelectron Energy Distribution Studies on Solids

Abstract: A 127° electrostatic cylindrical analyzer has been adapted for photoemission measurements. The resolution of the unit is 1.3% at 20 eV, increasing to 3.5% at 2 eV. The transmission is about 9% for energies higher than 6 eV. Integral photocurrents down to 10−15 A can be analyzed with a signal‐to‐noise ratio of 100. Digital data acquisition allows differentiation of the measured energy distribution spectra to enhance structure. The result is equivalent to an ac modulation technique with a considerable improvement in signal‐to‐noise ratio for a given integration time. Data on platinum are used as an example.

An Improved Interferometric Polarization Analyzer for Measuring the Microwave Magneto-Kerr Effect in Semiconductors

Abstract: An interferometric polarization analyzer for measuring the microwave magneto-Kerr effect in semiconductors is described and analyzed, and compared with earlier systems used for the same purpose. The system described utilizes a 4-port waveguide junction referred to as a dual-mode transducer (DMT). This system has important advantages over systems previously used to measure the microwave magneto-Kerr effect. Preliminary data taken with the system are presented and sources of error discussed.