Differential particulate mass monitor with intrinsic correction for volatilization losses

Apparatus for measuring the mass of particulate matter, including volatile components thereof, in a particle laden gas stream, comprising:

• means for forming said particle laden gas stream into a first stream and a second stream;
• a first mass detector and a second mass detector;
• means for directing said first stream to continually engage said first mass detector and for directing said second stream to continually engage said second mass detector;
• first stream particle removal means upstream of said first mass detector for removing substantially all particulate matter from said first stream when said first stream particle removal means is activated;
• second stream particle removal means upstream of said second mass detector for removing substantially all particulate matter from said second stream when said second stream particle removal means is activated;
• control means for alternately activating only one of said first stream particle removal means and said second stream particle removal means over an alternating sequence of successive measurement time periods;
• and
• 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.

Apparatus for measuring the mass of particulate matter in a particle laden gas stream, comprising:

• a first mass detector and a second mass detector;
• a source of a particle free gas stream otherwise substantially identical to said particle laden gas stream;
• a switching device 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;
• and
• a data analyzer determining a difference between a first reading provided by said first mass detector and a second reading provided by said second mass detector for said successive measurement time periods, which difference intrinsically corrects for volatilization losses occurring during said measurement time periods, and determining from said difference a measure of the mass or concentration of particulate matter in the particle laden gas stream.

Apparatus for measuring the mass of particulate matter in a particle laden gas stream, comprising:

• a 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 mass detector during an alternating sequence of successive measurement time periods;
• and
• a data analyzer for determining a difference between a first reading provided by the mass detector for a current measurement time period and a second reading, which difference intrinsically corrects for volatilization losses occurring during the current measurement time period, and for determining from said difference a corrected measure of the mass or concentration of particulate matter in the particle laden gas stream.

Apparatus for measuring the mass of particulate matter in a particle laden gas stream, comprising:

• a mass detector;
• an electrostatic precipitator for providing a particle free gas stream otherwise substantially identical to said particle laden gas stream;
• and
• switching means for causing said particle laden gas stream and said particle free gas stream to alternately engage said mass detector during an alternating sequence of successive measurement time periods.

Apparatus for measuring the mass of particulate matter, including volatile components thereof, in a particle laden gas stream, comprising:

• a mass detector;
• means for directing said stream to continually engage said mass detector;
• particle removal means up stream of said mass detector for removing substantially all particulate matter from said stream when said particle removal means is activated while maintaining said gas stream otherwise substantially the same;
• and
• control means for activating said particle removal means for alternate successive time periods.

Apparatus for measuring the mass of particulate matter, including volatile components thereof, in a particle laden gas stream, comprising:

• a mass detector;
• means for directing said stream to continually engage said mass detector;
• an electronic precipitator upstream of said mass detector for removing substantially all particulate matter from said stream when said particle removal means is activated;
• and
• control means for activating said electrostatic precipitator for alternate successive measurement time periods.