Process instrumentation, portable

EC detection is a promising alternative for capillary electrophoresis microchips due to its inherent characteristics, allowing a proper miniaturisation of the devices and compatibility with the fabrication processes, in case of an integrated detection. Moreover, the low cost associated permit the employment of disposable elements. As the EC event occurs on the surface of electrodes and the decrease in size usually results in new advantages (see Chapter 32), the possibilities of incorporating EC detectors are broad. The simplicity of the required instrumentation, portable in many cases, suit well with the scaling-down trend. Moreover, as the sample volume in conventional micro-channel devices is less than 1 nL, a very highly sensitive detector should be constructed to analyse even modest concentrations of sample solutions. Since sensitivity is one of the accepted characteristics of EC detection EC-CE microchips approach to the ideal analytical devices. 

Benchtop conductivity meters are not as prevalent now, as portable and handheld devices have become commercially available. These are discussed further in the sections on portable instruments and process instruments. The conductivity meter is often combined with other electrochemical measurements on the same device, e.g. pH or dissolved oxygen. 

The modern Russian MIA flaw detectors use pulse version of the method [1-3], which peirnits to produce very portable (0.7 - 1.5 kg) and simple instruments, convenient especially for in-service testing. The objects to be tested are multilayer structures of reinforced plastics, metals and other materials honeycomb panels, antenna fairings, propellers, helicopter rotors and so on. In mentioned instruments amplitude-frequency analog signal processing is used. 

The unique appearance of an infrared spectrum has resulted in the extensive use of infrared spectrometry to characterize such materials as natural products, polymers, detergents, lubricants, fats and resins. It is of particular value to the petroleum and polymer industries, to drug manufacturers and to producers of organic chemicals. Quantitative applications include the quality control of additives in fuel and lubricant blends and to assess the extent of chemical changes in various products due to ageing and use. Non-dispersive infrared analysers are used to monitor gas streams in industrial processes and atmospheric pollution. The instruments are generally portable and robust, consisting only of a radiation source, reference and sample cells and a detector filled with the gas which is to be monitored. 

In parallel with improvements in chemical sensor performance, analytical science has also seen tremendous advances in the development of compact, portable analytical instruments. For example, lab-on-a-chip (LOAC) devices enable complex bench processes (sampling, reagent addition, temperature control, analysis of reaction products) to be incorporated into a compact, device format that can provide reliable analytical information within a controlled internal environment. LOAC devices typically incorporate pumps, valves, micromachined flow manifolds, reagents, sampling system, electronics and data processing, and communications. Clearly, they are much more complex than the simple chemo-sensor described above. In fact, chemosensors can be incorporated into LOAC devices as a selective sensor, which enables the sensor to be contained within the protective internal environment. Figure 5... 

A portable electronic data acquisition system was transported to the plant site and connected to the extruder panel. All available instrument outputs from the panel were connected in parallel with the acquisition system. Data collected included barrel zone temperatures, screw speed, motor current, pressure at the entry to the pump, transfer line temperature, and gear pump temperature. Process data were collected at a frequency of once every five seconds. 

Practical FTIR solutions have been developed by paying attention to the fundamental design of the instrument. Moving an FTIR instrument out of the benign enviromnent of a laboratory to the more alien environment of either a process line or that of a portable device is not straightforward. A major emphasis on the instrument design in terms of both ruggedness and fundamental reliability of components is critical. Furthermore, issues such as enviromnental contamination, humidity, vibration and temperature are factors... 

Vibrational spectroscopy, in the form of mid-IR, NIR and Raman spectroscopy has been featured extensively in industrial analyses, both quality control (QC), process monitoring applications and held-portable applications [1-6]. The latter has been aided by the need for advanced instrumentation for homeland security and related HazMat applications. Next to chromatography, it is the most widely purchased classihcation of instrumentation for these measurements and analyses. Spectroscopic methods in general are favored because they are relatively straightforward to apply and to implement, are rapid in terms of providing results, and are often more economical in terms of service, support and maintenance. Furthermore, a single spectrometer or spectral analyzer, in a near-line application, may serve many functions, whereas chromatographs (gas and liquid) tend to be dedicated to only a few methods at best. 

This paper reports on research involved the design, construction, and evaluation of a portable instrument, a "luminoscope", for detecting skin contamination by coal tars via induced fluorescence. The instrument has been used in the laboratory to measure the fluorescence of various coal tars and recycle solvents from liquefaction processes spotted on filter paper on rat and on hamster skin. The practical use of the devices in field test measurements to monitor skin contamination of workers at coal gasifier is discussed. The paper also discusses the practicality and usefulness of the luminescence method for detecting skin contamination. 

A more modern method to check for loss of thickness in process piping is by ultrasonic testing (UT) or Sonaray. These are portable instruments used to check pipe thickness on-stream. Do not forget, though, that the thin elbow, the one that is sure to fail, is always out of reach unless a ladder can be found. And the inspector cannot find the ladder. The outside radius of elbows are typically the thinnest portions of a pip-... 

The technical development is still very rapid and addresses the growing need within process monitoring. The current trend includes further improvement of instrument design for smaller and more rugged equipment, integration into automated analytical systems and miniaturisation for multiple installations and portability. 

Fig. 50.1. Photograph of the Immuspeed instrument coupled to a portable computer comprising the Immusoft programme serving to load the test protocol, to run the assays, and to process the results. The figure also shows an artist view of the 8-channel Immuchip cartridge used in the current work and a schematic drawing of a micro-channel cross section with inlet, outlet, working electrodes, and electrical connection tracks the arrow shows the position of the cartridge insertion into the reception compartment of Immuspeed which comprises a temperature controller below the chip.

Over time, a large number of traditional laboratory instruments have been morphed to meet industrial needs for QC applications. Example applications include raw material, product QC and also some environmental testing. In such scenarios laboratory instruments appear to work adequately. Having said that, there are issues the need for immediate feedback and the need for smaller, cheaper, and more portable measurements. There is a growing interest in the ability to make measurements in almost any area of a process, with the idea that better production control can lead to a better control of the process and of the quality of the final product. The cost of implementation of today s (2004) process analyzers is still too high, and it is impractical to implement more than a couple of instruments on a production line. Also, there is growing concern about the operating environment, worker safety, and environmental controls. 

Recovery of metals such as copper, the operation of batteries (cells) in portable electronic equipment, the reprocessing of fission products in the nuclear power industry and a very wide range of gas-phase processes catalysed by condensed phase materials are applied chemical processes, other than PTC, in which chemical reactions are coupled to mass transport within phases, or across phase boundaries. Their mechanistic investigation requires special techniques, instrumentation and skills covered here in Chapter 5, but not usually encountered in undergraduate chemistry degrees. Electrochemistry generally involves reactions at phase boundaries, so there are connections here between Chapter 5 (Reaction kinetics in multiphase systems) and Chapter 6 (Electrochemical methods of investigating reaction mechanisms). 

If a surface-sensitive solid is processed in one site and needs to be transported to the analysis site without exposure to the atmosphere, a vacuum briefcase or special transportation module needs to be used. This would consist of a small portable vacuum chamber that is capable of attaching and transferring samples between processing and analysis stations. Understandably, designs of such instruments are system specific and often complicated. Most manufacturers of vacuum and surface analysis systems can offer customized options for specific systems. 

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