초록 ▼

The mass of particulate matter in a particle laden gas stream is measured using a first mass detector and a second mass detector. Switching means causes the particle laden gas stream and a substantially identical but particle-free gas stream to alternately engage the first mass detector and the seco

The mass of particulate matter in a particle laden gas stream is measured using a first mass detector and a second mass detector. Switching means causes the particle laden gas stream and a substantially identical but particle-free gas stream to alternately engage the first mass detector and the second mass detector respectively during successive measurement time periods. A difference between a reading provided by the first mass detector and a reading provided by the second mass detector for each of the successive measurement time periods is determined. This difference intrinsically corrects for volatilization losses occurring during the measurement time periods. A measure of the mass or concentration of particulate matter in the particulate laden gas stream is determined from this difference.

대표청구항 ▼

[What is claimed is:] [1.]a first mass detector and a second mass detector;first means for providing a particle free gas stream otherwise substantially identical to said particle laden gas stream;switching means for causing said particle laden gas stream and said particle free gas stream to alternat

[What is claimed is:] [1.]a first mass detector and a second mass detector;first means for providing a particle free gas stream otherwise substantially identical to said particle laden gas stream;switching means for causing said particle laden gas stream and said particle free gas stream to alternately engage said first mass detector and said second mass detector respectively during an alternating sequence of successive measurement time periods; andsecond means for determining a difference between a first reading provided by said first mass detector and a second reading provided by said second mass detector for each of said successive measurement time periods, which difference intrinsically corrects for volatilization losses occurring during said measurement time periods, and for determining from said difference a measure of the mass or concentration of particulate matter in the particle laden gas stream.