Topic
Spectrum analyzer
About: Spectrum analyzer is a research topic. Over the lifetime, 12217 publications have been published within this topic receiving 101851 citations.
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17 May 2005TL;DR: In this article, a method and an apparatus for time-of-flight (TOF) mass spectrometry was proposed, which consists of an ion source for emitting ions in a pulsed manner, an analyzer for realizing a helical trajectory, and a detector for detecting the ions.
Abstract: A method and apparatus for time-of-flight (TOF) mass spectrometry. The apparatus improves the ion focusing properties in an orthogonal direction and permits connection with an orthogonal-acceleration ion source for improvement of sensitivity. The apparatus comprises an ion source for emitting ions in a pulsed manner, an analyzer for realizing a helical trajectory, and a detector for detecting the ions. The analyzer is composed of plural laminated toroidal electric fields to realize the helical trajectory.
25 citations
TL;DR: In this paper, an acoustical analyzer system analyzes the operating characteristics of an acoustic device by operator selection of frequencies and amplitudes of test tone signals, automatically generating test tone signal signals representative of the selected frequencies or amplitudes and driving the acoustic devices thereby to produce output signals from the device, sampling the output signals, generating sampled signals, applying Fast Fourier Transform analysis to the sampled signals to generate readout signal therefrom and operating readout means via the readout signals to display the operating characteristic of the device.
Abstract: An acoustical analyzer system analyzes the operating characteristics of an acoustical device by operator selection of frequencies and amplitudes of test tone signals, automatically generating test tone signals representative of the selected frequencies and amplitudes and driving the acoustical device thereby to produce output signals from the device, sampling the output signals, generating sampled signals representative of the output signals, applying Fast Fourier Transform analysis to the sampled signals to generate readout signals therefrom and operating readout means via the readout signals to display the operating characteristics of the device.
25 citations
TL;DR: In this article, a real-time data analysis and transient memory (DATM) unit was designed and constructed for the analysis of rising bubbles in metallurgical systems and two phase flow in horizontal tubes.
Abstract: An ultrasonic method has been chosen to examine liquid/gas interfacial areas in closed systems. Although commercial equipment was used for the transducer and ultrasonic analyzer, commercial transient memory devices were inadequate. Consequently, a real‐time data analysis and transient memory (DATM) unit was designed and constructed. A series of flight times for a succession of 1024 signals are calculated and recorded in the transient memory. The system clock operates at 10 MHz and increments a 12‐bit binary counter. The counter is capable of measuring return signal times as long as 212 μs (4.096 ms) with a 1‐μs resolution. The data are available as analog voltages for display on an oscilloscope or the digital data may be directly transferred to a microcomputer for analysis, display, or archival storage. The DATM device was successfully applied, collecting data for the analysis of rising bubbles in metallurgical systems and two‐phase flow in horizontal tubes.
25 citations
TL;DR: The programming approach for adapting both simple and more complex statistical nonlinear regression data-fitting routines to the Fast Analyzer’s computer is discussed, and how the analyzer may be used to determine simple kinetic parameters for placental alkaline phosphatase and glucose-6-phosphate dehydrogenase is illustrated.
Abstract: The evaluation of steady-state enzyme kinetic parameters such as Km, Vmax , and Ki is useful in clinical enzymology, particularly where they can be used for the detection of enzyme variants and to assess the type of isoenzymes and the extent of their abnormal activity. The multiple-cuvet parallel-analysis feature of the Fast Analyzer permits one to evaluate one or more enzymic parameters in a single rotor. Both on-line measurement of initial reaction velocities and rapid off-line reduction of statistical data can be obtained by using the small-computer interfaced Fast Analyzer. Estimates of error in determining these parameters are also obtained, for use in comparing results in future analyses. We discuss the programming approach for adapting both simple and more complex statistical nonlinear regression data-fitting routines to the Fast Analyzer’s computer. We illustrate how the analyzer may be used to determine simple kinetic parameters for placental alkaline phosphatase and glucose-6-phosphate dehydrogenase and for the more complex "stripping out" of Km ’s and Vmax ’s for a heterogenous mixture of placental and intestinal alkaline phosphatase.
25 citations
TL;DR: In this article, a lock-in analyzer for nonlinear systems is proposed for intermodulation atomic force microscopy, which is implemented on a field-programmable gate array, providing speed in analysis, real-time feedback and stability in operation.
Abstract: Nonlinear systems can be probed by driving them with two or more pure tones while measuring the intermodulation products of the drive tones in the response. We describe a digital lock-in analyzer which is designed explicitly for this purpose. The analyzer is implemented on a field-programmable gate array, providing speed in analysis, real-time feedback and stability in operation. The use of the analyzer is demonstrated for Intermodulation Atomic Force Microscopy. A generalization of the intermodulation spectral technique to arbitrary drive waveforms is discussed.
25 citations