Patent ID: 7614280

Claim:
A biological quantitative fit test (bio-QNFT) system for the testing of masks and respirator systems, said bio-QNFT system comprising: an exposure chamber for receiving and retaining a challenge atmosphere, said challenge atmosphere comprising a concentration of an aerosol comprising particles output from an aerosol generation device, wherein said aerosol generation device aerosolizes an inert oil for producing the challenge atmosphere comprising a concentration of an aerosol comprising particles having a size range equivalent to hazardous airborne biological agents, and wherein said aerosol generation device includes a virtual impactor having a major air stream and a minor air stream for separating particles according to a desired size range comparable to a size range of hazardous airborne biological agents, wherein the minor air stream has a slower moving airflow than the major air stream, and wherein the virtual impactor separates relatively larger particles from a remainder of particles, and the relatively larger particles are concentrated into the minor air stream and forced into said exposure chamber so that particles entering the chamber have a size range equivalent to hazardous airborne biological agents while the major air stream is discarded and does not enter the chamber, said exposure chamber to permit fit testing of said mask or respirator system; and at least one aerosol sampling subsystem for measuring a concentration and/or quantity and size of particles of a sample of the challenge atmosphere retained within said exposure chamber, and a concentration and/or quantity and size of particles of a sample from within said mask or respirator system when configured for use, said aerosol sampling subsystem including an aerosol spectrometer for counting particles according to size so that particles comparable in size to hazardous airborne biological agents are accurately counted within said sample of said exposure chamber and from within said sample from said mask or respirator system according to a predetermined number of categories over a size range comparable to airborne biological agents.