ISA CAP Technology & Tools 3

Question 1

Which ISA standard governs the functional safety of Safety Instrumented Systems (SIS) in the process industry?

Accepted Answer

ISA-84 (IEC 61511)

Answer

ISA-84, which is equivalent to IEC 61511, establishes the requirements for the design, installation, and maintenance of Safety Instrumented Systems in the process industry.

Question 2

In process instrumentation, what does the term 'turndown ratio' describe?

Accepted Answer

The ratio of maximum to minimum measurable flow for a given instrument accuracy

Answer

Turndown ratio (also called rangeability) is the ratio of the maximum to the minimum flow that an instrument can measure within its specified accuracy.

Question 3

What is the function of a SCADA Remote Terminal Unit (RTU) in a typical oil and gas pipeline system?

Accepted Answer

Collects field data and transmits it to the master station via a communication link

Answer

An RTU acquires data from local field instruments and control equipment, then transmits it to the SCADA master station while executing commands received from the master.

Question 4

A thermocouple produces a voltage based on which physical phenomenon?

Accepted Answer

Seebeck effect

Answer

Thermocouples exploit the Seebeck effect, where a temperature difference between two dissimilar metal junctions generates a measurable electromotive force (EMF).

Question 5

In ISA-5.1 instrumentation symbology, what does a circle with a line through the middle (bisected circle) on a P&ID represent?

Accepted Answer

A shared display/shared control device located in the main control room

Answer

ISA-5.1 uses a circle bisected by a horizontal line to represent a shared display/shared control instrument located in the primary instrument panel or main control room.

(ISA CAP) ISA Certified Automation Professional Practice Test

(ISA CAP) ISA Certified Automation Professional Practice Test

ISA CAP Technology & Tools 3