Traditional monitoring techniques

At present, the traditional monitoring techniques cannot meet the requirements of modern structural monitoring because of some deficiencies as follows ... 

Ng and Assirelli have carried out a mixing study in batch stirred vessels with working volumes of 3 L to 20L using a fiber-optic UV-vis monitoring technique. Bromophenol blue sodium salt was used as a non-reactive tracer. The results on traditional Rushton turbines and 45° angled pitched blade turbines showed good agreement with a typical conductivity technique and a correlation proposed in literature. 

For their characterization, electrochromic compounds are initially tested at a single working electrode under potentiostatic control using a three-electrode arrangement. Traditional characterization techniques such as cyclic voltammetry, coulometry, chronoamperometry, all with in situ spectroscopic measurements, are applied to monitor important properties [27]. From these results, promising candidates are selected and then incorporated into the respective device. 

Current IPC detectors are on-stream monitors. HPLC detectors range from (1) non selective or universal (bulk property detectors such as the refractive index (RI) detector), characterized by limited sensitivity, (2) selective (discriminating solute property detectors such as UV-Vis detectors) to (3) specific (specific solute property detectors such as fluorescence detectors). Traditional detection techniques are based on analyte architecture that gives rise to high absorbance, fluorescence, or electrochemical activity. Mass spectrometry (MS) and evaporative light scattering detectors (ELSDs), can be considered universal types in their own right... 

Dueholm S. (1996) Determination of density profiles of wood based panels from traditional laboratory techniques to continuous, in-line, real-time monitoring. In Maloney T (ed) Proceedings of 30th Washington State University, Pullman, Washington, 45-57 Eaton RA and Hale MD (1993) Wood decay, pests and protection. Chapman and Hall, London... 

Traditional inspection methods have known limitations (such as lack of accessibility to difficult- to-reach areas), can involve personnel safety concerns, and are not always reliable (such as operational inaccuracies due to scale formation, noise, or vibration) all of these add a measure of uncertainty to the effectiveness of the inspection and raise concern about the possibility of undetected corrosion problems in areas that cannot be inspected. For a comparison of monitoring techniques, see Table 3.1. 

In this chapter, we first introduce traditional process monitoring techniques (Section 21.1) that are based on limit checking of measurements and process performance calculations. In Section 21.2, the theoretical basis of SPC monitoring techniques and the most widely used control charts are considered. We also introduce process capability indices and compare SPC with standard automatic feedback control. Traditional SPC monitoring techniques consider only a single measured variable at a time, a univariate approach. But when the measured... 

The practice of using actual operating conditions of plant equipment and systems to optimize total plant operation. Relies on direct equipment monitoring to determine the actual mean-time-to-failure or loss of efficiency for each machine-train and system in a plant. This technique is used in place of traditional run-to-failure programs. 

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