The process parameters that is selected for control is the ---- variable

The process parameter selected for control is referred to as the control variable. This term is fundamental in process control systems. The control variable is the specific aspect of the process that needs to be maintained at a desired setpoint or condition. For instance, in a temperature control system, the temperature would be the control variable that the system aims to maintain at a specific level.

In many control systems, the behavior of the control variable is influenced by various other factors, which may include input variables (such as raw material properties or external conditions) and output variables (which represent the results of the process, like product quality). However, the primary focus for a control system is to maintain the control variable, ensuring that it responds appropriately to changes and deviations from the desired setpoint.

Understanding the significance of the control variable is essential for those working in instrumentation and process control, because it directly impacts the effectiveness and efficiency of a system's operation.