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November 2009

ISA Certified Control Systems Technician (CCST) program

Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

This question comes from the Level I study guide, Domain 3, Troubleshooting. Level I represents a professional who has a five-year total of education, training, and/or experience.

CCST question

In this drawing, FY 901 is a (an) ______________ function.

A. time

B. multiplication

C. square root

D. summing

CCST answer

The correct answer is A, a time function.

FY 901 is a “circle” enclosed in a “square,” which indicates it is an instrument that has a shared display or a shared control. The “901” is the “loop number.” The “F” indicates this is “flow” related, and the “Y” is saying there is some kind of conversion or computation going on. The way we know it is a “time related” conversion is from the “f(t)” notation at the top right hand corner of the box. The output of FY 901 equals the input times some function of time or equals some function of time alone.