Pressure Measurement Quiz

Which of the following is equivalent to 1 atmosphere pressure in metric units?

• 14.5 lbf/in²

• 1.013 bar

• 14.7 bar

• 1.013 Newton

Which of the following describes Vacuum Gauge Pressure?

• Measures pressure below atmospheric and uses absolute zero as datum (zero)

• Measure pressures below absolute zero and uses atmospheric pressure as datum (zero)

• Measures pressures below atmospheric and uses atmospheric pressure as datum (zero)

• Measures pressures below absolute zero atmospheric and uses absolute zero as a datum (zero)

Which of the following is the base unit for pressure in the SI system?

• Pounds force per square inch

• Pascal

• bar

• Newton

If a pressure gauge is 5 metres below the water main it is measuring, which of the following statements is true?

• The gauge would read low due to head of liquid acting against the applied pressure

• The gauge would read high due to the head of liquid acting in the same direction as the applied pressure

• The gauge would read high due to the head of liquid acting against the applied pressure

• The gauge would read low due to the head of liquid acting in the same direction as the applied pressure

There are two pressure instruments measuring the same parameter and one is calibrated in psia and the other in psig. Which of the following statements is true?

• The psia reads approx. 14.7 higher than the one showing psig pressure

• Both gauges would read approx. the same

• The psia gauge reads approx. 14.7 lower than the one showing psig pressure

• The psia gauge reads approx. 1.013 lower than the one showing psig pressure

A bourdon tube (0-10bar gauge pressure) pressure gauge is required to measure the pressure of a water main which is 10 metres below the gauge. The gauge has been correctly calibrated using a dead weight tester. What would the gauge be expected to read before being reconnected to plant?

• FSD

• Minus 0.981bar

• 0.981bar

• Zero

A pressure switch has a normally open microswitch which is required to raise an alarm when the pressure is increased and reaches 5 bar. From the following list, pick how the instrument should be calibrated?

• Break on falling pressure

• Break on rising pressure

• Make on falling pressure

• Make on rising pressure

A pressure instrument when tested displays hysteresis. What results would show this?

• The instrument has an offset throughout its range

• The instrument is correct at zero and FSD but incorrect at mid scale

• The instrument is correct at zero and FSD but the upscale and downscale values are different

• The instrument is correct at zero and shows a straight line on graph but reads too low at FSD

If a differential pressure transmitter is to be calibrated in situ, which of the following would be most appropriate test equipment to use?

• A DMM (Digital multi meter)

• A dead weight tester

• A comparator pump

• A Druck 600 series calibrator

A 4-20mA current loop system is reading 0mA when tested by connecting a Fluke meter in series. Which of the following would be a likely cause of fault?

• Zero pressure differential

• DP cell isolation valves closed

• Break in transmission loop

• Hysteresis