1. Control Loop

2. ELEMEN-ELEMEN DALAM CONTROL LOOP
1. Level Sensor -> Bubbler. 2. Level Transmitter. 3. Controller. 4. I/P Transducer. 5. Final Control Element/Control Valve.

3. DIAGRAM KERJA

4. Sistem Kerja Set point dan Proses Variable -> Difference.
Difference akan membandingkan set point value dengan proses variable -> Controller.
Controller akan memproses output signal (Signal to control element) sebagai Manipulated Variable -> I/P Transducer.
I/P Transducer akan merubah elektronic signal menjadi pneumatic signal (As the signal form is changed by a converter, the original information about the value of the measured variable is preserved) -> Final Control Element.
Final Control Element/Control Valve akan menyesuaikan nilai proses variable dengan set point (Opened/closed to maintain a set point level) -> Proses -> Output.
. Set Point – PV = % error.
. Jika Deviation = 0 , maka PV = Set point.
Sensor akan mengirimkan input signal (proses variable information) -> Level Transmitter.
Level Transmitter akan mengirimkan output signal -> Difference.