Sulfur dioxide pollution monitor

Claim 2

An SO2 pollution monitor comprising: a flow-type fluorescence cell; means for flowing a sample stream of air, smokestack gas or the like whose SO2 concentration is to be monitored through said cell; means for irradiating said sample stream in said cell with a beam of ultraviolet in the region from about 2100 to 2300 A. whereby said SO2 in said sample stream fluoresces in the region from about 2400 to 4200 A. with an intensity that varies substantially linearly with SO2 concentrations over a wide range of values; and means for measuring said SO2 fluorescence intensity at right angles to said irradiating beam, said measuring means being linearly calibrated in terms of SO2 concentration over said range.

Claim 3

An SO2 pollution monitor comprising: a flow-type ultraviolet fluorescence cell; means for flowing a sample stream of air, smokestack gas or the like whose SO2 concentration is to be monitored through said cell; means for irradiating said sample stream in said cell with a beam of ultraviolet in the region of about 2138 A. whereby said SO2 in said sample stream fluoresces in the region from about 2400 to 4200 A. with an intensity that varies substantially linearly with SO2 concentrations from about 0.1 to 500 ppm, said fluorescence intensity being negligibly dependent on the water vapor content of said sample stream; and means for measuring said SO2 fluorescence intensity at right angles to said irradiating beam, said measuring means being linearly calibrated in terms of SO2 concentration from about 0.1 to 500 ppm.

Claim 4

An SO2 pollution monitor comprising: a flow-type ultraviolet fluorescence cell; means for flowing a sample stream of air, smokestack gas or the like whose SO2 concentration is to be monitored through said cell; means for irradiating said sample stream in said cell with a beam of ultraviolet in the region of about 2138 A. whereby said SO2 in said sample stream fluoresces in the region from about 2400 to 4200 A. with an intensity that varies substantially linearly with SO2 concentrations from about 0.1 to 500 ppm, said fluorescence intensity being negligibly dependent on the water vapor content of said sample stream; and means for measuring said SO2 fluorescence intensity at right angles to said irradiating beam, said measuring means being linearly calibrated in terms of SO2 concentration from about 0.1 to 500 ppm.

Claim 5

A monitor as set forth in claim 2, wherein said irradiating means comprises a zinc vapor discharge lamp operating on alternating current and means for focussing an image of the discharge thereof in said sample stream in said cell.

Claim 6

A monitor as set forth in claim 3 and further including filter means disposed beTween said lamp and said cell for passing wavelengths in the region below about 2500 A. and for rejecting longer wavelengths.

Claim 7

A monitor as set forth in claim 2 and further including filter means disposed before said fluorescence intensity measuring means for passing wavelengths in the region from about 2400 to 4200 A. and for rejecting substantially all other wavelengths.

Claim 8

An SO2 pollution monitor comprising: a flow-type ultraviolet fluorescence cell; means for flowing a sample stream of air, smokestack gas or the like whose SO2 concentration is to be monitored through said cell; means for irradiating said sample stream in said cell with a beam of ultraviolet in the region of about 2288 A. whereby said SO2 in said sample stream fluoresces in the region from about 2400to 4200 A. with an intensity that varies substantially linearly with SO2 concentrations from about 0.1 to 1600 ppm, said fluorescence intensity being dependent to a limited extent on the water vapor content of said sample stream in said cell; and means for measuring said SO2 fluorescence intensity at right angles to said irradiating beam, said measuring means being linearly calibrated in terms of SO2 concentration from about 0.1 to 1600 ppm whereby readings therefrom may be corrected according to the amount of water vapor in said sample stream.

Claim 9

An SO2 pollution monitor comprising: a flow-type ultraviolet fluorescence cell; means for flowing a sample stream of air, smokestack gas or the like whose SO2 concentration is to be monitored through said cell; means for irradiating said sample stream in said cell with a beam of ultraviolet in the region of about 2288 A. whereby said SO2 in said sample stream fluoresces in the region from about 2400to 4200 A. with an intensity that varies substantially linearly with SO2 concentrations from about 0.1 to 1600 ppm, said fluorescence intensity being dependent to a limited extent on the water vapor content of said sample stream in said cell; and means for measuring said SO2 fluorescence intensity at right angles to said irradiating beam, said measuring means being linearly calibrated in terms of SO2 concentration from about 0.1 to 1600 ppm whereby readings therefrom may be corrected according to the amount of water vapor in said sample stream.

Claim 10

A monitor as set forth in claim 6, wherein said irradiating means comprises a cadmium vapor discharge lamp operating on alternating current and means for focussing an image of the discharge thereof in said sample stream in said cell.

Claim 11

A monitor as set forth in claim 7 and further including filter means disposed between said lamp and said cell for passing wavelengths in the region below about 2500 A. and for rejecting longer wavelengths.

Claim 12

A monitor as set forth in claim 6 and further including filter means disposed before said fluorescence intensity measuring means for passing wavelengths in the region from about 2400 to 4200 A and for rejecting substantially all other wavelengths.

Claim 13

A monitor as set forth in claim 6 wherein said measuring means comprises a photomultiplier tube connected to a recorder or a counter.