ISA Interchange

AutoQuiz: What is the Difference Between Indication of an Instrument and Actual Value of Measured Variable?

Written by Joel Don | Jul 31, 2015 1:00:12 PM

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

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.

The difference between the indication of the instrument and the actual value of the measured variable is:

A) the controlled variable
B) called set point
C) an error in the measuring instrument
D) discarded
E) none of the above

The prompt is very nearly the definition of an error signal-the difference between the indication and the ideal value of the measured signal (set point)-and thus seems familiar. Actually we have a bad meter here.

The correct answer is C.

About the Editor
Joel Don is the community manager for ISA and is an independent content marketing, social media and public relations consultant. Prior to his work in marketing and PR, Joel served as an editor for regional newspapers and national magazines throughout the U.S. He earned a master's degree from the Medill School at Northwestern University with a focus on science, engineering and biomedical marketing communications, and a bachelor of science degree from UC San Diego.

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