Lesson 1 - The Nature of Process Control
Process variables; On-off control; Measuring data; Controlling variables, Error and feedback; Open- and closed-loop control
Learning Objectives:– Define setpoint and error.
– Explain how measurement and control are related in industrial processes.
– Describe the four essential functions of an automatic control system.
– Discuss the functions of the CRT and PLC in control systems.
– Identify variables in industrial processes.
– Explain the importance of feedback in a closed-loop control system.
Lesson 2 - Elements of Process Control
Analog and digital control signals; ASCII; Measuring pressure, level, and flow rate; Digital pulse control; System terminology; Controller action
Learning Objectives:– Discuss the differences between modern automatic control systems and older ones.
– Identify the standard signals used in process control.
– Define the terms commonly used in control terminology.
– Explain the differences between open-loop control and closed-loop control.
– Describe on-off, proportional, integral, derivative, and PID controller action.
Lesson 3 - Process Control Signals
Linear and nonlinear transducers; Signal operating values; Error; Controller output; Pneumatic and electrical signal transmission; Control loops
Learning Objectives:– Discuss standard signals and linearity and explain how to calculate the value of a variable from an instrument's span and range.
– Describe five common sources of error in signal measurement.
– Discuss the basic principles governing pneumatic signal transmission and explain how a flapper-nozzle device works.
– Describe the function of the controller in a control loop.
– Discuss the basic principles governing electrical signal transmission, including Ohm's law, and list standard current and voltage signals.
– Explain the function of I/P devices in a typical control system and discuss the use of digital signals and optical signals.
Lesson 4 - Process Measurement Fundamentals
Measurement and display requirements; Remote and local display; Calibration; Noise; Response time; Measurement system and observation error
– Explain why measurement is necessary and discuss conditions that affect the degree of accuracy required.
– Compare the advantages of linear and nonlinear displays.
– Compare analog and digital devices and explain how each is applied to measurement.
– Name five sources of measurement error.
– Discuss proportionality and explain how it applies to transmitters.
Lesson 5 - Principles of Transducer Operation
Outputs; Mechanical, electrical, and pneumatic elements and response; Resistance, voltage, and frequency devices; Combining elements
– Discuss the need for linearity in a process.
– List examples of mechanical and electrical transducer elements.
– Compare pneumatic response and electrical/electronic response in transducers.
– Describe the operation of the bourdon tube, bellows, and diaphragm.
– Name examples of resistance, voltage response, frequency response, and electromechanical devices and explain how they work.
– Discuss the use of the Hall-effect transducer and the differential transducer.
Lesson 6 - Basic Process Measurement Systems
Interaction of system elements; Transmitters; Electrical vs. pneumatic output; Converters; Signal conditioning; Indicators and recorders
– Discuss the basic elements of measuring systems and explain how they interact.
– Describe how a physical quantity is translated into another quantity.
– Discuss the use of transmitters to relay information from one location to another and explain the transfer function.
– Describe the operation of at least five kinds of converters.
– Compare analog and digital indicators and recorders.