Computers for data processing

Emission spectrometer incorporating sample and counter electrodes, means of excitation, prism or grating monochromator, photomultiplier detection system, microprocessors or computers for data processing, interference correction and data display. 

Improvements in analytical methods as well as in chemometrics have allowed the redeterminations of the atomic mass values of some nuclides.235 It is of interest to establish a true test of the reliability of data sets because of the differences obtained in successive published values of data. This reliability will be assured only by using competitive analytical methods that employ suitable computers for data processing. 

The analytical process comprises three main steps, which can be represented as shown in Figure 7.1. As can be seen, there are two primary time-consuming steps the input and the output. The black box represents the measurement of the analytical information it needs half the time that is required by the input or output steps.3 The input step includes sample preparation and is a very difficult step to perform, especially when spectrometric methods are used. The output step includes data processing. The introduction of the computer for data processing improves the quality of the analytical information, as well as the rapidity and reliability of this step. 

Rapidity is one of conditions for laboratory quality control. The time needed to develop an analytical process must be as short as possible. The length of time required influences the efficiency of analytical process since, as everyone is well aware, "time is money." The time an analytical process takes influences the cost of the analysis. It is also very important to consider the influence and effect of time on the aging of the analytical method. Automation of the analytical process, for all practical purposes, fulfulls the rapidity requirements. The rapidity of the analytical process is dependent on the reliability of the analytical method and that of the instrument. An increase in the reliability of an analytical process decreases the time required for analysis, and the use of computers for data processing decreases the time needed for analytical signal processing. 

The utilization of computers for data processing minimizes the value of uncertainty for this step of the analytical process. The computer should contain a specific program required for the type of analysis that is done. For data processing, certain spreadsheet programs320 that assure a minimum value of uncertainty in data processing have been reported. 

For structural determination, a high resolution NMR is required and this type of instrument is discussed first. Low resolution instruments are discussed in Section 3.5.7. The most important parts of an FTNMR instmment are the magnet, the RF generator, and the sample chamber or probe, which not only houses the sample but also the RF transmission and detection coils. In addition, the instrument requires a pulse generator, an RF receiver, lots of electronics, and a computer for data processing. A block diagram of an FTNMR is shown in Fig. 3.19(a). 

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