CLASSIFICATION OF THE INPUT AND OUTPUT VARIABLES IN A CHEMICAL PROCESS

The input variables can be further classified into the following categories:

1.. Manipulated (or adjustable) variables, if their values :can be adjusted freely by the human operator or a control mechanism and

ii. disturbances, if their values are not the result of adjustment by an operator or a control system.

The output variables are also classified into the following categories:


i. Measured output variables, if their values are known by directly measuring them, and

ii. -unmeasured output variables, if they are not or cannot be measured directly.