ISA CAP Control Systems & Instrumentation 3

Question 1

In ISA S88 batch control, what is the role of a 'unit procedure'?

Accepted Answer

An ordered set of unit operations that makes one type of product

Answer

A unit procedure is an ordered set of unit operations that directs a unit to make a batch of a specific product.

Question 2

What phenomenon occurs when integral action continues to accumulate during a period when the controller output is saturated?

Accepted Answer

Integral windup

Answer

Integral windup occurs when the integrator keeps accumulating error while the output is at its limit, causing sluggish response when the constraint is released.

Question 3

A differential pressure transmitter used for level measurement in a closed vessel requires:

Accepted Answer

High-side connection at the bottom and low-side at the vapor space

Answer

The high-side tap senses hydrostatic head plus vapor pressure, while the low-side tap cancels the vapor pressure, yielding a signal proportional only to liquid level.

Question 4

In FOUNDATION Fieldbus, what is the function of a 'function block'?

Accepted Answer

A software algorithm inside a device that performs a specific control or I/O task

Answer

Function blocks are standardized software algorithms (e.g., AI, PID, AO) that execute within fieldbus devices to implement control and I/O functions.

Question 5

Which of the following is the correct ISA symbology for a flow indicating controller on a P&ID?

Accepted Answer

FIC

Answer

FIC stands for Flow Indicating Controller, combining the measured variable (F), the indicating function (I), and the control function (C).

(ISA CAP) ISA Certified Automation Professional Practice Test

(ISA CAP) ISA Certified Automation Professional Practice Test

ISA CAP Control Systems & Instrumentation 3