With an on/off controller:
A)the output is either completely on or completely off.
B)a positive deviation of the process variable from its set point causes the controller to shut the control element off.
C)a negative deviation of the process variable from its set point causes the controller to turn the control element on.
D)all of these.

Question

Quizplus · Accepted Answer

An on/off controller operates by turning the control element (for example, a valve) completely on or completely off in response to the process variable exceeding or falling below the set point. Thus, the output is either completely on or completely off (A). When the process variable deviates positively from its set point, the controller shuts off the control element (B), and when the process variable deviates negatively from its set point, the controller turns the control element on (C). Therefore, all of these statements are correct (D).

With an On/off Controller