Verified answer

There are many many particulate matter sampling devices in use for many different reasons on many different kinds of systems in the U.S.

They cover a wide range of efficiencies and capabilities depending on what they are used for and how much is spent on the equipment and its operation.

Of course some of the systems will change as better technologies are developed.

Currently in use are filter methods, pezio electric, electrostatic precipitation, momentum capture, scrubbing, etc