Perturbation of Photoacoustic and Transmission Measurements Due to the Mixing of Non-Absorbing, Scattering Particles with Particulate Carbon Collected on Teflon Filters

A widely used nondestructive technique for monitoring ambient levels of carbon in the atmosphere is the integrating plate method (IPM)(1) which takes advantage of the unique optical properties of elemental carbon (soot) by measuring the ambient by which a beam of light is attenuated when passing through a field loaded filter. Another absorptive technique is photoacoustic detection (PAD), a process which may be potentially more accurate than IPM for ambient measurements.