An electronic PI temperature controller has an output p of 12 mA when the set point equals the nominal process tmperature. The controller response to step change in the temperature set point of 3 mA (equivalent to a change of 5 degrees F) is shown below
t,s p, mA
0- 12
0+ 10
20 9
60 7
80 6
Determine the controller gain Kc (mA/mA) and the integral time, tau(sub l). Is the controller reverse-acting or direct-acting?