(Solved): Consider the ratio control scheme shown in Fig. 15.6. Each flow rate is measured using an orifice ...

Consider the ratio control scheme shown in Fig. 15.6. Each flow rate is measured using an orifice plate and a differen- tial pressure (D/P) transmitter. The pneumatic output signals from the

transmitters are related to the flow rates by the expressions

Each transmitter output signal has a range of

. The transmitter spans are denoted by

and

for the disturbance and manipulated flow rates, respectively. Derive an expression for the gain of the ratio station

in terms of

, and the desired ratio

. Figure 15.6 Ratio control, Method II.