Figure 2-7. Portable carbon monoxide monitor.
Figure 2-8. Infrared analyzer for general-purpose gas
analyzer and portable gas analyzer.
c. Particles. Contaminants in the form of particulate may be sampled in several
ways, depending on the size of the individual particles.
(1) Impingement or impactors. These devices require a means of collecting
atmospheric air (such as a pump), which forces the air into the device, where the
particles strike various surfaces due to inertia, and are collected on these surfaces.
Such devices sometimes employ a medium, on which the particles impinge and are