Instrumentation debugging

Visualisation of profiles inside complex equipment is a valuable instrument for understanding how the unit really works. A typical example is the plot of profiles insides a distillation column, in term of pressures, temperatures, and composition on stages, as well as of material and enthalpy flows. These profiles are highly recommended for debugging non-convergenee problems. Even in the case of successful runs internal profiles allow the evaluation of design elements. For example, the inspection of temperatures and composition profiles can easily identify incorrect feed loeation or superfluous stages in a distillation column. 

Does the system run, compute, and so on This is a standard engineering question. It involves issues of physical measurement and instrumentation for hardware, and runtime inspection and debugging... 

In equation-based simulators, the mathematical equations that describe the physical process are entered into an equation solver that then uses appropriate techniques to solve them. In modular-based process simulators, the mathematical equations that describe the physical process are coded into modules that the user "flow sheets" together. Modular-based process simulators are preferred over equation-based simulators because it is easier for the user to "map" the real world into the virtual one, and programming and debugging of the modules are easier than analyzing sets of equations (Popovic and Bhatkar, 1997). However, equation-based simulators have proved highly successful in the field of optimum process control. Equation-based models handle instrument error and incorrect or errors from modeling simplifications better than modular-based simulators. Modular-based simulators invariably have a data reconciliation step, where the model is nm against values obtained from the instrumentation system and then a least-squares fit is performed to fit the model to the process. 

With the love of his wife from Finland, Terttu Soininen, Sweden became their country of choice to reside and raise two wonderful daughters. It was a lucky decision, because the University of Stockholm offered Paul the opportunity to advance one of his talents, mathematics, which he pursued within a practical context meteorology. Another fortunate coincidence was that he became involved in computer modeling early on. In those days, he was debugging the code for predicting weather and storms by listening to the hums of the mechanical processors. The development of these skills was instrumental for an unparalleled vocation in atmospheric and environmental science. 

---