Process control, automatic sampled data

Statistical process control (SPC) aligns data of measured samples with historical trends and control limits which are based on observed statistical data. Notifications to process engineers or immediate corrective actions are triggered automatically if an instable behavior of the controlled process is recognized (Dietrich and Schulze 2003). 

A multi-channel sample instrument or an automatic switching valve can be used when multiple locations or samples need to be monitored simultaneously. For example, such systems have been developed and manufactured which can monitor multiple points from a central location, including both continuous and discrete sampling systems. The systems can be connected to either PC s or process computers for further data processing or for activation of process controllers or operation alarms. 

Sample preparation for XRD is rapid and data is acquired by a computer which also controls the sample changer. A typical acquisition time would be a few hours. For routine operations, such as determining zeolite lattice parameters, it is also possible to process data automatically. Phase identification, aided by a JCPDS database search software, takes a few tens of minutes. 

If you have to perform assays by quantitative TLC, you will find fully automatic sample application indispensable. This will at least require the Automatic TLC Sampler (ATS 3) of CAMAG (Fig. 34), in which a PC controls the application and then, in combination with a TLC scanner, the evaluation. The PC also processes the measured data. The samples are applied from a steel capillary, which is connected to a dosing syringe driven by a stepping motor. The samples are applied to precoated layers (on glass or foil), up to the 20 x 20 cm format, either spotwise or bandwise as required. Applica-... 

The services of the analytical chemist are constantly increasing as more and better analytical tests are developed, particularly in the environmental and clinical laboratories. The analyst often must handle a large number of samples and/or process vast amounts of data. Instruments are available that will automatically perform many or all of the steps of an analysis, greatly increasing the load capacity of the laboratory. The data generated can often be processed best by computer techniques computers may even be interfaced to the analytical instruments. An important type of automation is in process control whereby the progress of an industrial plant process is monitored in real time (i.e., online), and continuous analytical information is fed to control systems that maintain the process at preset conditions. 

Automated devices are widely used in process control systems, whereas automatic instruments of various sophistication are used in the analytical laboratory for performing analyses. The latter may perform all steps of an analysis, from sample pickup and measurement through data reduction and display. 

Perhaps the most important advance in commercial thermal analysis instrumentation during the past 10-12 years has been the use of microprocessors and/or dedicated microcomputers to control the operating parameters of the instrument and to process the collected experimental data. This innovation is by no means unique to thermal analysis instrumentation alone since these techniques have been applied to almost every type of analytical instrument. Unfortunately, the automation of thermal analysis has not become a commercial reality. Complete automation is defined here as automatic sample changing, control of the instrument, and data processing. Such instruments were first described by Wendlandt and co-workers in the early 1970s (See Chapters 3 and 5) although they lacked microprocessor control of the operating conditions. 

The temperature of the primary crystallization was measured using the thermal analysis method recording the cooling and heating curve of the studied samples. A computer-controlled automatic thermal analysis device with a subsequent statistical processing of the output data was used. The reproducibility of the temperature of the primary crystallization measurement was 2 K. 

Obviously the use of a personal computer is an important step toward automation of the analysis. The computer can control the automatic sample changer, the timing of the analysis, counting, storing of the spectra, and finally, data processing. 

There is no doubt that automatic data processing has found an increasing application in calorimetry. Microprocessor technology permits automatic control of calorimeters with a continuous adjustment of such parameters as heating power, heating rate, temperature, and so on in accordance with the pertinent data of the caloric process in the sample. There are already calorimeters in which the results of the measurement are given automatically in a corrected, calibrated, desmeared form. Such a computer-controlled calorimeter may be called a smart calorimeter. 

Iron sintering mix control and composition stabilization. For an efficient sintering process, a constant and optimized basicity of raw mix without short and long term fluctuations is a must. Achieving real-time automatic process control without human factor influence requires on-line elemental composition data. Figure 8.29a presents typical breakdown spectra of the sintering mix and the results of industrial LIBS unit test data, where laboratory CaO control data are compared with online analyzer readings. One hundred and forty samples have been taken from conveyer belt and send to laboratory for control analysis. It was found that the correlation of... 

It is important to emphasize that the development of fiber optics technology is a fundamental cornerstone that allowed for the development of real in-line and in-situ monitoring spectroscopic techniques, as the sampling device can be placed at very harmful environments, while the spectrometer still sits in a process control room. Without the support of fiber optics technology, samples have to be prepared and placed inside the illuminated chambers (as performed in the lab since the nineteenth century) or pumped through sampling windows (as performed in advanced systems intended for process and product development, such as automatic continuous online monitoring of polymerization reactions (ACOMP) [37- 1] in order for spectral data to be obtained. 

The titration process has been automated so that batches of samples can be titrated non-manually and the data processed and reported via printouts and screens. One such instrument is the Metrohm 670 titroprocessor. This incorporates a built-in control unit and sample changer so that up to nine samples can be automatically titrated. The 670 titroprocessor offers incremental titrations with variable or constant-volume steps (dynamic or monotonic titration). The measured value transfer in these titrations is either drift controlled (equilibrium titration) or effected after a fixed waiting time pK determinations and fixed end points (e.g. for specified standard procedures) are naturally included. End-point titrations can also be carried out. 

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