Engineering measurement

Madron, F, A New Approach to the Identification of Gross Errors in Chemical Engineering Measurements, Chemical Engineeiing Science, 40(10), 1985, 1855-1860. (Detection, elimination)... 

Madron, F. (1985). A new approach to the identification of gross errors in chemical engineering measurements. Chem. Eng. Sci. 40, 1855-1860. 

We will also attempt to link everyday experiences with fiber and film production to the industrial engineering measures taken to improve polymer quality. The similarities based on non-textbook knowledge are thus emphasized. In-depth considerations regarding special technologies would be beyond the scope of this present chapter. Therefore, the main focus is to present a modern state of knowledge regarding the relationship of polymer quality and the requirements of the processes. 

Natural gas (NG) consists of 85-95% methane (CH ), which is the simplest hydrocarbon. NG is the cleanest burning alternative fuel. Exhaust emissions from NG vehicles are much lower than those from gasoline-powered vehicles. Combustion of NG reduces carbon dioxide content compared with diesel, but the lost efficiency when the Otto process is used means that carbon dioxide emissions increase. All in all combustion of NG in a gasoline engine gives rise to about as much carbon dioxide as the combustion of diesel in a diesel engine, measured in units of energy. 

The cetane number, however, is an engine measurement that requires a skilled operator and a well performing engine to determine. Because of the variability among engines and the differences in operator skill, engine number determinations can differ. 

Formal acceptance testing to an agreed-upon specification is to be carried out on the developed software and hardware and for the engineered measurement and control instrumentation. This is intended to prove to the pharmaceutical manufacturer that all components and documentation are available and the system functions as defined in the system specifications. The acceptance test specification should include verifications and tests covering the following ... 

By contrast, satisfactory practical mechanical, electrical, optical, and thermal measurements are often made adequately for the purpose at hand, even if less accurate than corresponds to the optimum achievable uncertainty relative to true value expressed under SI. Routine measurements in these fields can thus be expressed conveniently in terms of the relevant SI unit to an uncertainty determined principally by the uncertainty of the practical measurement in the field. 1 Harmony among most physical and engineering measurements can be achieved to the uncertainty of the measurement in the field by traceability of all measures to the SI unit without invoking an intermediate standard 2 or RM. 

The Convention of the Metre dates back to 1875, so there is a long history to the traceability of the results of physical and engineering measurements to international standards. Admittedly the mole was added to the base units in 1971 but there was little or no involvement of the International Committee of Weights and Measures (CIPM) in chemical measurements until a decade ago. It is therefore not surprising that traceability is not so well established for chemical measurements. 

Batch processes are often nonisothermal and characterized by nonlinear dynamics, whose effects are further emphasized by intrinsically unsteady operating conditions. Hence, methodological and technological problems related to batch chemical reactors are often very challenging and require contributions from different disciplines (chemistry, chemical engineering, control engineering, measurement, and sensing). 

In principle, we can measure the potential of an electrode with a hydrogen reference electrode. We can also calculate the reversible potential of the cell composed of the electrode of interest and the hydrogen reference electrode. In practice, a hydrogen electrode is difficult to operate properly and is rarely used in engineering measurements. Instead, commercially available reference electrodes (e.g., calomel, Ag/AgCl, and Hg/HgO) are used. 

Fig - 3 - Temperatures behind the engine (measuring point 2)t with a medium-size exhaust gas pipe volume... 

Find out what protective engineering measures the residents undertook to hold the sea back from the land. These may include any of the following ... 

Calculated RON values corresponded to engine values of debutanized reformate samples (25 samples) with a standard deviation of 0.55 RON units, which is close to the accuracy of engine measurements. By carrying out a number of repeated test runs, the reproducibility taken as the standard deviation for the measured reformate and hydrogen yields were determined as 0.25 and 0.02 wt%, respectively, and 0.25 units for RON. In order to achieve this a detailed calibration of the GC system was carried out, and the reactor thermocouples, the hydrogen mass flow controllers and naphtha feed pumps were thoroughly calibrated between each test run. 

Equation (7.16) is applied over a short period of time. In it, dQ is comprised of the sum of the chemical heat release during this time, obtained from equation (7.13) which, in turn, depends upon equations (7.8), and the heat lost to the surrounding boundaries. Under engine conditions the last is evaluated from appropriate heat transfer data [76,151-154]. Finite difference forms of the equations, for small time increments, yield values of incremental temperature change in equation (7.16). The last term in this equation depends upon the temperature and pressure changes in the end gas and these depend upon the piston and flame motions. They may be obtained from either engine measurements or an engine model, as discussed in Sections 7.5.4 and 7.5.5, respectively. 

In 1985 Leppard [156] reported engine measurements, for stoichiometric ethane-air, of pressure and end gas temperature, the latter derived from the energy equation. The occurrence of autoignition agreed closely with prediction based on an earlier chemical model of Westbrook and Dryer [52]. From their engine experiments, Cowart et al. [59] also compared, for iso-octane and -pentane, the predictions of the simplified models of Hu and Keck [75] and Chun et al. [157], and the more detailed kinetic predictions of Westbrook et al. [158]. These were found to simulate the time of knock occurrence if the kinetic data were re-calibrated. This, and the subsequent work of Brussovansky et al. [76], showed the need for accurate allowances for heat transfer and piston blow-by, because of their important effect on the derived end gas temperature. Where end gas temperature can be measured directly this problem is circumvented. 

High NO percentage in idle engine measurements. Atmos Environ 17 1395-1398. 

American Society of Civil Engineers. Measurement of Oxygen Transfer in Clean Water ANSI/ASCE Standard 2-91, 2nd Ed. American Society of Civil Engineers Reston, VA, 1992. 

As a rule process engineering measurements in the laboratory are carried out with the aim of supplying design data for the industrial plant. For this purpose it is required that a complete similarity exists between the process on laboratory-scale and that on industrial-scale, which is expressed in identical numerical values for the process-describing numbers Hi = idem (see Section 1.6, Dimensional analysis). 

The growing demand for recyclability of industrial products calls for respective design-engineering measures. 

Zigrang, D. J. "Elements of Engineering Measurements." Department of Mechanical Engineering, University of Tulsa, Oklahoma, 1985. 

Since in practical chemistry and physics— not to mention engineering—measurements of heat quantities play a very important part, the equation dS = dQ/T is of great value. It provides a mathematical formulation of a condition of equilibrium. 

N. Maluf, An introduction to microelectromechanical systems engineering. Measurement Science and Technology, 13(2), 229, 2002. 

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