AutoQuiz: What Reading Do You Get From a Disconnected Pressure Gauge?

AutoQuiz is edited by Joel Don, ISA’s social media community manager.

Today’s automation industry quiz question comes from the ISA Certified Control Systems Technician (CCST) program. Certified AutoQuiz-20151204-absolute-pressure-gaugeControl System Technicians calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables. Click this link for information about the CCST program. This question is from the Level I study guide, Domain 1, Calibration. Level I represents a professional who has a five-year total of education, training, and/or experience.

What pressure, in pounds per square inch (psi), would be indicated by an absolute pressure gauge that is lying on a workbench not connected to anything?

a) 0
b) 29
c) 14.7
d) 2.9
e) none of the above

   

Click Here to Reveal the Answer

Atmospheric pressure (Patmospheric), absolute pressure (Pabsolute), and gauge pressure (Pgauge) have the following mathematical relationship.

Pabsolute = Pgauge + Patmospheric

Atmospheric pressure is 14.7 psi.

The correct answer is C.

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  • Lydia Miller

    Technically, isn’t that answer is only correct at sea level?

    • Lydia, thanks for that technical note.

    • Lydia, thanks for that technical note.