It is desired to control the composition and the level of the mixing tank used to prepare a saline solution at the nominal value by two PID controllers. There are $2$ inlet streams entering the mixing tank. Density of the mixture can be assumed constant through out the mixing process. The dilute inlet stream has a constant composition of $10$ wt$\%$ with a nominal flowrate of $5$kg$/$min$.$ The other concentrated stream has a constant composition which is $80\%$ and has a nominal stream flowrate of $4$kg$/$min$.$ It is desired to keep the level of the cylindrical mixing tank with a crosssectional area of $1$m$2$ at $3$m$.$Construct the block diagram in simulink. And analyze the effect of one of the PID controller parameters on the response characteristics for a unit step change in disturbance variable.