Microprocessor technology

Microprocessor-Based Transmitters The cost of microprocessor technology has declined to the point where it is economic ly feasible to incorporate a microprocessor into each transmitter. Such microprocessor-based transmitters are often referred to as smart transmitters. As opposed to conventional or dumb transmitters, the smart transmitters offer the following capabilities ... 

Microprocessor technology permitted these technical issues to be addressed in a cost-effec tive manner. In the mid-1970s, a process control architecture referred to as a distributed control system (DCS) was introduced and almost instantly became a commercial success. A DCS consists of some number of microprocessor-based nodes that are interconnec ted by a digital communications network, often called a data highway. The key features of this architecture are as follows ... 

The foregoing demonstrates that modern digital devices offer highly reliable, state-of-die-art microprocessor technology that controls turbomachinery strings, monitors operating data, stores data for subsequent evaluation, communicates to odier systems, and can expand with future technologies. 

Recent advancements in microprocessor technology coupled with the expertise of companies that specialize in machinery diagnostics and analysis technology, have evolved the means to provide vibration-based predictive maintenance that can be cost-effectively used in most manufacturing and process applications. These microprocessor-based systems simplify data acquisition, automate data management, and minimize the need for... 

Commercial autonomic apparatus with microprocessor technology, but with more emphasis on routine analysis, also became available, viz., the Metrohm 646 VA processor and the PARC Model 384B polarographic analyser the main features of these are worthy of brief consideration here. 

Analytical procedure is a systems problem and the samphng, pretreatment, measurement, data collection and reduction, and final reporting all have to be considered in a fiilly automatic approach. Computerization is often considered to he synonymous with automation but, although microprocessor technology is certainly changing the face of automatic instrumentation and influences both the control aspects and the data reduction, computerization is only a part of automation. Computers should simply be considered as tools of the trade within the area of automation. 

Since the 1970s, process controls have evolved from pneumatic analog technology to electronic analog technology to microprocessor-based controls. Electronic and pneumatic controllers have now virtually disappeared from process control systems, which are dominated by programmable electronic systems based on microprocessor technology. 

Measurement Devices and Final Control Elements This lowest layer couples the control and information systems to the process. The measurement devices provide information on the current conditions within the process. The final control elements permit control decisions to be imposed on the process. Although traditionally analog, smart transmitters and smart valves based on microprocessor technology are now beginning to dominate this layer. 

This book is fundamentally and deliberately a methods manual and it is for this reason that modem electronic wizardry is treated briefly. I do not however underestimate the contribution that microprocessor technology will make to routine analysis versatility, convenience and ease of use are but three characteristics that have already been demonstrated. For a similar reason the theoretical aspects are presented in sufficient detail for a basic understanding of the principles involved, rather than a rigorous treatment. 

FIGURE 20.6 SRAM-cell size is a key metric of scaling for microprocessor technologies. Intel Corp. maintains a 50 % aerial shrink of SRAM cell with each technology (a). 45-nm technology SRAM cell (b) is the latest addition to the trend. The dotted line represents the six transistor cell—horizontal lines are the MOS gates and the vertical lines are diffusion regions (from Ref 5). 

In 1960, emission spectroscopy was displaced by the arrival of atomic absorption spectroscopy but experienced a revival in 1970 with the appearance of modem excitation sources, such as Inductively Coupled Plasma (ICP), the development of electronic detection methods and microprocessor technology. 

Microprocessor technology had a great impact on the development of radioisotope instraments. Linearisation of complex calibration curves, compensation for the decay of the radioisotope, and performance of important calibration checks can be handled easily by the microprocessor. In this way, radioisotope instmments of modem design added yet another dimension of reliability and sophistication to their proven excellence. 

The introduction of microprocessor technology, in connection with modem stationary phases of high chromatographic efficiencies, makes it a routine task to detect ions in the medium and lower ppb concentration range without pre-concentration. The detection limit for simple inorganic anions and cations is about 10 ppb based on an injection volume of 50 pL. The total amount of injected sample lies in the lower ng range. Even ultrapure water, required for the operation of power plants or for the production of semiconductors, may be analyzed for its anion and cation content after preconcentration with respective concentrator columns. With these pre-concentration techniques, the detection limit could be lowered to the ppt range. However, it should be emphasized that... 

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