Signal Detection and Processing

Radiation Detectors. The question of how to compare different radiation detectors, especially those which work by different principles, remains difficult. Usually, several parameters are given by manufacturers. These include  

FIGURE 9. Comparison between the output voltage of an IR detector and its noise voltage V . 

InSb-HgCdTe detector is used by Kunimatsu/ with the advantage of a wider spectral range. Performances of the three types of detectors also are given in Table V. 

Enhancement of the Signal. A large contribution to the success of infrared reflectance spectroscopy at the electrode/electrolyte interface results from the coupling of spectroscopic and electrochemical techniques. Furthermore, due to the strong absorption of the solvent and the subsequent weakness of the emerging beam, it is indispensable to use extremely powerful additional techniques to extract the signals buried in noise. 

Therefore, in addition to the spectrometer itself and controlling microcomputer, equipment is required firstly to monitor the electrochemical processes occurring at the metal/solution interface (e.g., a potentiostat and waveform generator) and secondly to enhance the signal prior to its storage and processing. Usually the signals in phase with a reference modulation are detected 

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It is now some twelve years since the first volumes of this series were published. Perhaps the most significant advances during that time, particularly for the photochemist, have been the further development of lasers and the tremendous increase in speed and complexity of electronic devices used for signal detection and processing. These have spawned a number of new techniques for the study of kinetics and drastically modified some of the traditional methods. The aim of this chapter is to show how and where some of these techniques can be applied. 

Ibrahim, K. and Bachalo, W., The significance of the Fourier Analysis in Signal Detection and Processing in Laser Doppler and Phase Doppler Applications. Proc. of the 6th Int. Symp. on Appl. of Laser Techn. to Fluid Mechanics, Lisbon, Portugal, paper 21.5 (1992)... 

The spectral region of interest is then detected and processed by means of an optical multichannel analyzer (EG G-PARC model 1215, OMA). The OMA detector SIT (silicon intensified target), EG G-PARC model 1254 has been used. It is operated by the detector controller, EG G-PARC, model 1216, which performs the signal digitization as well. The acquired spectra are displayed in real time on a TV display and on the OMA console. The data storage and processing are also performed by that console which has a 28K of 16 bit core memory and a floppy disk for permanent storage. 

Materials Photoacoustic measurements were made on a component-assembled PAS spectrometer consisting of a 9W argon ion laser (Spectra Physics), a 0.5 cc internal volume PAS cell equipped with a sensitive electret microphone (Radio Shack, 3.2 mV/Pa). Circular polarization modulation was achieved with a special low frequency (220 Hz) photoelastic modulator (15) (Hinds International). Signals were detected and processed with a vector tracking lock-in amplifier (PAR model 5204), and intensity modulation was done with a 30-slot blade mechanical chopper (Ortec). Syntheses of all compounds were by well established literature methods. 

They tested the effect of gambierol on taste buds from mouse vallate papilla by using the patch-clamp technique to monitor membrane ion currents. These excitable cells are believed to be sensory cells able to detect food chemicals, so alterations on the ionic currents produced by the toxin could affect the signal transduction and processing. 

Figure 7.1 Schematic of the detection and processing of nuclear magnetic resonance signals. The...

Fault detection and isolation are a prerequisite of fault diagnosis necessitating system observability and proper signal measurement and processing in the presence of noise. The thus obtained information then is to be processed in real time by a decision support software system that takes into account that sensors themselves can be faulty. According to Venkatasubramanian et al. [14-16], fault detection and diagnosis methods may be classified into... 

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