Plot the root locus diagram for the Plot the root locus diagram for the system shown in . We may consider this system to consist of a process having negligible lag; an underdamped, second-order measuring element; and a PD controller. This system may approximate the control of flow rate, in which case the block labeled K p would represent a valve having no dynamic lag. The feedback element would represent a flow measuring device, such as a mercury manometer placed across an orifice plate. Mercury manometers are known to have underdamped, second-order dynamics. Plot the diagram for t D 13 We may consider this system to consist of a process having negligible lag; an underdamped, second-order measuring element; and a PD controller. This system may approximate the control of flow rate, in which case the block labeled K p would represent a valve having no dynamic lag. The feedback element would represent a flow measuring device, such as a mercury manometer placed across an orifice plate. Mercury manometers are known to have underdamped, second-order dynamics. Plot the diagram for t D 13 .