PIC Tutorial 11 (Chap k Pneumatic)

The standard transmission signal range for pneumatic system is

• 1.4 kg/cm2.
• 4 – 20 mA.
• 3 – 15 PSI.
• 0.2 – 1.0 PSI.

The standard output range for an electronic transmitter is

• 4 to 20 mA.
• 9 to 12 VDC.
• 87.5 to 108 MHz.
• 0.2 to 1.0 kg/cm2.

What are the adjustments needed for calibrating the pneumatic transmitter?

• Zero adjustment.
• Span adjustment.
• Zero or Span adjustment.
• Zero and Span adjustment.

A flow transmitter is calibrated to measure 0-25 l/min. What is the transmitter signal when the flow rate is 17.5 l/min?

• 5.4 mA.
• 9.5 mA.
• 15.2 mA.
• 18.7 mA.

A I/P (Current to Pressure) converter will change a 16 mA signal into

• 3 psi.
• 9 psi.
• 12 psi.
• 15 psi.

During maintenance, the transmitter is zero checked to

• ensure accuracy.
• to reduce hysterisis.
• increase its sensitivity.
• protect against wear-and-tear.

The 3-valve manifold piping system in a transmitter is used for

• higher production rates.
• cheaper application.
• higher accuracy and precision.
• easier maintenance and calibration.

In the above diagram, when valve A is closed, valve B and valve C are open, it is to:

• calibrate the zero.
• calibrate the span.
• shut down the process.
• commission the transmitter.

Output 0% of an electrical transmission signal is

• 0 mA.
• 4 mA.
• 12 mA.
• 20 mA.

AC signal is not used for transmission in an electronic system because it is

• more expensive than DC.
• not a pure positive signal.
• easily subject to interference.
• difficult to achieve the desire value.