PO Quality Control & Sampling 2

Question 1

What is the purpose of a calibration check on a field analyzer before taking a reading?

Accepted Answer

To confirm the analyzer is reading accurately against a known reference

Answer

Calibration checks verify that the instrument reads correctly by comparing its output against a certified reference standard.

Question 2

In statistical process control, what does a 'run of 7 points' above the mean on a control chart indicate?

Accepted Answer

A possible process shift or assignable cause that should be investigated

Answer

Seven consecutive points on one side of the mean is a non-random pattern that signals a likely process shift requiring investigation.

Question 3

A gas chromatograph (GC) is used in a refinery primarily to:

Accepted Answer

Separate and identify chemical components of a gas mixture by composition

Answer

A GC separates gas mixture components and quantifies their concentrations, providing detailed compositional analysis for process control and product quality.

Question 4

What is the primary difference between a 'grab sample' and an 'automatic inline analyzer'?

Accepted Answer

Grab samples are taken manually at a point in time; inline analyzers provide continuous real-time data

Answer

Grab samples capture a snapshot at one moment while inline analyzers continuously monitor and provide real-time data to operators and the DCS.

Question 5

Why must sample cylinders for flammable gas be pressure-tested before use?

Accepted Answer

To ensure the cylinder can safely contain the sample pressure without leaking or failing

Answer

Pressure testing confirms that sample cylinders are free of defects and can safely hold the pressurized sample, preventing hazardous leaks.

PO - Process Operator Certification Practice Test

PO - Process Operator Certification Practice Test

PO Quality Control & Sampling 2