Which of the following are NOT devices utilized to sample/measure particulate matter?

The choice that is not a device used to sample or measure particulate matter is traffic flow rates. Traffic flow rates pertain to the measurement of vehicular movement and congestion on roadways, which is relevant for understanding traffic patterns and their impact on air quality but does not directly measure particulate matter itself.

In contrast, inertial/centrifugal collection equipment, electrostatic precipitator-type sampling devices, and impingers are all specific tools used for collecting and analyzing particulate matter in the air. Inertial/centrifugal collection equipment operates by using the principles of inertia to capture particles from a gas stream, serving as a means to sample airborne particles effectively. Electrostatic precipitators use electric charges to remove particles from a gas stream, making them valuable for controlling pollution in various settings. Impingers work by drawing air through a liquid that captures particulate matter, and are often used in microbiological or chemical sampling.

Understanding the purpose and operation of these sampling devices emphasizes the distinctions between them and non-sampling methods such as traffic flow assessments.