Method and apparatus for monitoring particulate mass concentration of emissions from stationary sources

A system for use in monitoring mass concentration of a stream of particulate material for which the particle size distribution may vary, said particulate material stream comprising particulate pollution ranging in particle size up to a maximum of approximately 10 .mu.m, said system comprising,

• a source of electromagnetic radiation for directing a beam of radiation through the particulate stream,
• radiation receiver means for measuring radiation from said radiation source transmitted through said particulate stream,
• said radiation source being operated at substantially a single wavelength at which the extinction coefficient-to-mass concentration ratio of the particulate material stream is substantially independent of variations in particle size for the range of particle sizes in the stream whereby the output from the receiver means provides a measure of mass concentration of the particulate material stream, said radiation source and receiver means operating between 3 and 4 .mu.m.

A system for use in monitoring mass concentration of a stream of particulate material for which the particle size distribution may vary, said system comprising,

• a source of electromagnetic radiation comprising a helium-neon laser operating at a wavelength of substantially 3.39 .mu.m for directing a beam of radiation through the particulate stream,
• radiation receiver means for measuring radiation from said radiation source transmitted through said particulate stream,
• said radiation source being operated at substantially a single wavelength at which the extinction coefficient-to-mass concentration ratio of the particulate material stream is substantially independent of variations in particle size for the range of particle sizes in the stream whereby the output from the receiver means provides a measure of mass concentration of the particulate material stream.

A method of measuring mass concentration of particulate material carried by a gaseous medium flowing through a conduit wherein the particulate material is of particle size distribution that can vary, said method comprising,

• employing radiant energy source and radiant energy detector means to obtain a measure of radiant energy transmission through said particle-containing gaseous medium,
• operating said radiant energy source and detector means at a single wavelength at which the extinction coefficient-to-mass concentration ratio is substantailly insensitive to particle size changes within the range of particle sizes flowing through the conduit whereby the measure of radiant energy transmitted provides a measure of mass concentration of particles independent of variations of particle sizes during said flow.

A method of measuring mass concentration of pollutant particulate material carried by a gaseous medium flowing through a conduit wherein the particulate material is of particle size distribution that can vary, said method comprising,

• employing radiant energy source and radiant energy detector means to obtain a measure of radiant energy transmission through said particle-containing gaseous medium,
• operating said radiant energy source and detector means at a single infrared wavelength between approximately 3 to 4 .mu.m at which the extinction coefficient-to-mass concentration ratio is substantially insensitive to particle size changes within the range of particle sizes flowing through the conduit whereby the measure of radiant energy transmitted provides a measure of mass concentration of particles independent of variations of particle sizes during said flow.