Why are personal monitors preferred over area monitors?

• A. Cheaper
• B. Easier to calibrate
• C. More accurate for exposure
• D. Less maintenance

Answer: (C)

Measuring the actual inhaled dose is the key idea. A personal monitor sits in the worker’s breathing zone and tracks the airborne concentration the person truly experiences over time, taking into account movement, task variety, and breathing rate. This directly reflects how much contaminant the worker inhales, which is what exposure limits protect. Area monitors, fixed in one spot, only show ambient air concentration at that location and can misrepresent what the worker actually breathes because concentrations can vary with location, airflow, and proximity to the source. So personal monitors give the most accurate picture of exposure and are preferred for assessing risk and ensuring compliance.