To determine the time constant and transfer function of first order process.
To observe the time response of closed loop second order process with proportional control.
The system considered in experiment had one major disadvantage, namely that there is considerable deviation present at all times. As deviation should operate the system, this implies that sensitivity is too low. In Process control this sensitivity is defined in terms of the proportional band.
This is the range of values of deviation that causes the controller output to cover its full operating range. This is often expressed as a percentage such that 100% proportional band means that the full range of outputs of the measuring systems causes the controller to operate over its full range.
An adjustment of the percentage of the proportional band varies the gain of the controller. The following experiment will examine the effects of changes in percentage of the proportional band and the response of the system to disturbances.
%PB 
Peak Overshoot Mp 
Rise Time t_{r}

Rise Time t_{p} 
Damping Ratio 
Setting time ts 






K_{p}= 100% / PB%
Thus the time response of closed loop second order process with proportional control was studied.
To study the time response of P + I controller.
The proportional control to maintain a stable system the gain level is such that the system is insensitive to deviation below the certain level. In an ideal system the measured value and the set value should be the same under steady state condition the deviation should be zero.
What is required is an alternative signal to be fed into the main amplifier of sufficient size to provide an output if a steady state deviation exists viz to reduce the offset to zero. Such a signal can be provided by an integrator which gives a constantly increasing output for a steady value input. Such an arrangement is known as proportional + Integral Controller and should reduce any steady state deviation to zero.
S.NO 
Proportiaona I Band PB 
Intagral Time

Peak Overshoot Mp 
Rice Time Tr 
Setting time ts 






Thus the time response of P + I controller was studied.
To study the response of P + I + D Controller in a process.
As seen in experiment the integral control improves the performance of the control system in some respects, i.e it reduces the steady state deviation, but has the disadvantage of slowing down the overall response time.
If a System is required to follow a sudden change in set value this would give rise to a rapid change in the deviation. Although this deviation change is rapid the system response rather slowly, So if at this time the controller output can be boosted, the speed of system response will be improved.
If the deviation is differentiated, i.e rate of change measured, and a signal produced proportional to this and then added to the signals from the proportional and integrator sections, some improvement may result. Such an arrangement is known as three term controller or PID Controller.
Proportional Band (PB) 
Integral Time (Ti) 
Rise Time (T_{r})

peak Time (T_{p}) 
Setting time (Ts) 
Peak Overshoot (Mp) 






Thus the response of P + I + D Controller in a process was studied.
we respect your privacy.