Introduction To Process Control
When you have completed this unit, you will be able to identify each of the components of the Process Control Training System. You will also be able to set up and operate a basic flow circuit using the Process Control Training System.
- 1.The primary purpose of process control is to maintain some _______
- A.
Digital Variable
- B.
Physical Variable
- C.
Analog Variable
- D.
Input Variable
- 2.The reason process control is so popular is the increased
- A.
Safety
- B.
Profitability
- C.
Operability
- D.
All of the above
- 3.Process control can be achieved either in the _____ or closed-loop mode.
- 4.The ________ is the desired value of the variable being controlled. The setpoint may be set manually, automatically, or it may be programmed by the operator.
- 5.The ________ (2 words) is a device which manipulates a variable that has a direct influence on the controlled variable.
- 6._____________ are varying conditions that cause the controlled variable to differ from the setpoint.
- 7.The __________ is an operation or sequence of operations involving a change in the controlled variable.
- 8.The _______________ (2 words) is a function of the manipulated variable and the disturbances.
- 9.The _______________ contains a sensing element that measures the actual value of the controlled variable and generates a proportional signal which is sent back to the controller.
- 10.The controller compares the setpoint to the measured variable and corrects for any difference between the two by readjusting the control element until the loop reaches a state of equilibrium called _______________
- 11.The disadvantage of the closed-loop mode is that the actual value of the controlled variable is not taken into account. If disturbances cause the controlled variable to deviate from the setpoint, no countermeasure is taken to correct for the deviations.
- A.
True
- B.
False
- 12.When many variables must be controlled simultaneously, this is known as ________________
- 13.The measure of acidity or alkalinity:
- 14.The set of devices used to measure, record, and control industrial processes.
- A.
Primary sensing elements
- B.
Indicators
- C.
Transmitters
- D.
Process Instrumentation
- 15.Transmitters use _______________________ as analog controller signals
- A.
Voltage
- B.
Resistance
- C.
Hydraulic Pressure
- D.
All of the above
- 16.Why do we use current of 4 to 20 mA for analog controller signals rather than 0 to 20 mA?
- A.
It allows transmitter devices to be powered by the same loop, as we always have at least 4 mA.
- B.
0 mA allows us to detect some failures in the loop.
- C.
All of the above.
- 17.ISA stands for:
- A.
Industrial Safety Authority
- B.
Industrial Safety Act
- C.
Industrial Standards Association
- D.
Instrument Society of America
- 18.Indicates the function and nature of a component represented. It is composed of letters and numbers:
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