This automation industry quiz question comes from the ISA Certified Control Systems Technician (CCST) program. Certified Control 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 more information about the CCST program.
A flow metering device comprised of a body, flow straightener, hub, bearing, rotor, and pickup is called a:
a) vortex shedding flowmeter
b) magnetic flowmeter
c) parshall flume
d) turbine flowmeter
e) none of the above
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Answer A is not correct, since a major component of a vortex shedding flowmeter is a bluff body, and vortex flowmeters do not have hubs, bearings, or rotors.
Answer B is not correct, since a major component of a magnetic flowmeter is an iron core, and these flowmeters do not have hubs, bearings, or rotors.
Answer C is not correct, since parshall flumes do not have any moving parts and require a measurement of fluid level above the convergence section and above the throat section.
The correct answer is D. The problem statement describes the major parts of a turbine flowmeter. The rotor is supported by the hubs and bearings inside of a flowmeter body, and as the rotor spins, the number of revolutions is determined with a magnetic pickup. The rotational speed of the rotor and the frequency of pulses are proportional to the volumetric flow rate through the meter.
Reference: Spitzer, David W., Flow Measurement, 2nd Edition