Description: serves as a reference variable for a slave controller; Name: output variable of the controller
Description: output variable of the controlling element, which is deducted from the control difference variable and is also the input variable of the actuator; Name: controller output variable
Description: pump H(Q) curve where the maximum head and shut-off head are coincidental, and the total head declines continuously as the rate of flow increases; Name: Pump H(Q) curve