Instrumentation spectrographic

Fixed optic, concave grating instruments (spectrograph type)... 

Mass spectrograph. An instrument in which beams of ions are separated according to their mass-to-charge ratio (m/z) and in which the deflection and intensity of the beams are recorded directly on a photographic plate or film. 

The capital cost of spectrographic analysis instrumentation is normally too high to justify in-plant testing. Typical cost for a microprocessor-based spectrographic system is between 30,000 and 60,000. Because of this, most predictive maintenance programs rely on third party analysis of oil samples. 

This section is concerned with describing the equipment which is necessary for an introduction to spectrographic techniques for the analyst. In this instance the practical work will be described for instruments manufactured by Rank Hilger, Margate, Kent, UK, but the comparable products of other manufacturers may also be used. 

The experiments in qualitative analysis described utilise a Hilger and Walts medium spectrograph. They can easily be adapted to other similar spectrographs with the aid of the instruction manuals supplied by the manufacturers of the instruments. 

Specific absorption coefficient 650 Specific gravities solutions of acids, (T) 829 of selected reagents (T), 829 Spectral half bandwidth 663 Spectrofluorimetry 731 Spectrograph adjustment of, 771 commercial instruments, 761, 775, 776 Spectrographic analysis see Emission spectrographic analysis... 

Spectrographically standardised substances 830 Spectrophotometer cells for, 664 data presentation, 665 double-beam, 667 layout of instruments, 666, 667 operation of, 672 radiation sources for, 664 single-beam, 666... 

The idealized calculations of the efficiency of the parts of an x-ray spectrograph (4.3, 4.4) can be modified to apply to a laboratory instrument if account is taken of the pulsating character of the applied voltage, the polychromatic nature of the x-ray beam, and the absorption in the beam path. 

The excitation of the analytical lines depends approximately on the square of the x-ray tube voltage (1.5) and is therefore very sensitive to the regulation of the high-voltage power supply. The performance of the other components of the x-ray spectrograph is not so sensitive to power supply regulation. It is usually convenient to regulate the entire power supply to the instrument because the x-ray tube is the major part of the load. 

A good diffractometer-spectrograph must function satisfactorily in each role, and it must be built so that the changeover from one to the other is easy, quick, and sure. Unless this is true, two instruments will often be needed where one might have sufficed. The diffractometer should handle either powder samples or single crystals. 

First, the conventional spectrograph is being converted into a sequential instrument that uses the comparative method (9.7). The conversion consists principally in equipping such a spectrograph (one x-ray beam, one crystal, one detector) with mechanisms that make possible the comparison of standard and unknown at preselected positions of 20. 

When analyses are done by the use of x-rays at intensities so low that quanta are counted, the reliability of x-ray methods involves considerations foreign to classical analytical chemistry, The reliability of x-ray emission spectrography will consequently be discussed in some detail. To illustrate the discussion, an error analysis of a laboratory spectrograph will be undertaken. This analysis can serve as a basis for corresponding examinations of larger instruments. 

X-ray spectral analysis, schematic diagrams of instruments for, 124, 125 X-ray spectrograph, curved-crystal, of Adler and Axelrod, 206, 207 definition, 124, 125 desirable conditions for, 162 estimated losses in, 124, 126, 127 General Electric XRD-5 D/S, 249-252 Industrial X-ray Quantometer, of Applied Research Laboratories, 256, 257... 

We have developed another bench for the measurement of the contrast value. Contrast measurement have been carried out on the MMA fabricated by Texas Instrument, in order to establish the test procedure (Zamkotsian et al., 2002a Zamkotsian et al., 2003). We can address several parameters in our experiment, as the size of the source, its location with respect to the micro-elements, the wavelength, and the input and output pupil size. In order to measure the contrast, the micro-mirrors are tilted between the ON position (towards the spectrograph) or the OFF position (towards a light trap). Contrast exceeding 400 has been measured for a 10° ON/OFF angle. Effects of object position on the micro-mirrors and contrast reduction when the exit pupil size is increasing have also been revealed. 

Advanced computerisation and sensorisation and developments in the field of multielement optical detectors (CCD and PDA) and fibre optic remote spectroscopy have added modularity and flexibility. Silica-silica fibres used for spectroscopy applications are multimode with core diameters from 50 to 1000 p,m. The application of new technologies to optical instrumentation (e.g. improved gratings in spectrographs, the use of... 

Instrumentally, spectral FLIM generates a spectrally resolved set of lifetimes by either introducing filters to provide spectral resolution or a spectrograph between the sample and image intensifier. The first such system was created for looking at the long lifetimes of lanthanide dyes [37]. Later, a spectral FLIM system was described for measuring from a two-dimensional (2D) area of a microscope field... 

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