Electronic instrumentation in petroleum refineries

Electronic process control systems have overcome the transmission limitations of conventional pneumatic equipment for centralized control, and have facilitated the application of electronic data logging and computational procedures. Product quality is the key parameter in refinery operations and continuous analysers have been developed to overcome the limitations of conventional laboratory testing. The design and performance criteria for process monitors are outlined, and instruments are described for the on-line measurement of specific gravity, boiling range, colour and composition. Continuous analysers can be used for process control and line blending, and similar analytical techniques could be applied to measure the quality of products in storage vessels. Electronic instruments are used for tank level and temperature gauging, flow metering and blending. New instrumental techniques are supplementing conventional methods for plant inspection and maintenance.