Direct and indirect refer to what in monitoring techniques?

• A. Scanner settings.
• B. Types of monitoring techniques.
• C. Forms of PPE.
• D. Area monitoring.

Answer: (B)

Direct and indirect refer to how monitoring data are collected—the approach or type of monitoring technique itself, not the equipment settings, personal protective equipment, or where you monitor.

Direct monitoring means measuring the contaminant in real time at the point of exposure or at the source with in-situ instruments. You get immediate readings and can respond quickly. For example, a handheld gas detector that displays concentration as you monitor is a direct method.

Indirect monitoring relies on collecting samples and sending them for laboratory analysis later. This provides precise quantification but with a delay, since the sample must be processed and analyzed. An example is taking air samples on a sorbent tube and analyzing them in a lab to determine contaminant levels.

So, the term describes the overall approach to monitoring—direct real-time measurement versus indirect sampling and lab analysis—rather than scanner settings, PPE, or area monitoring.