Inherently Second-order Processes

  • This kind of processes are not that common in chemical process control.

  • Mechanical systems and some sensors exhibit second order behavior.

  • Such a process can exhibit underdamped behavior, and consequently it cannot be decomposed into two first-order systems.

  • They are characterized by their inertia to motion.

  • Examples: simple manometers, externally mounted level-indicators, pneumatic valves.