US4151414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detection of extremely small particulate matter and vapors
Assignee: ABB Process Analytics Inc
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Filing: 1977-03-31
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Granted: 1979-04-24
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Expires: 1997-03-31
Abstract
Abstract The measurement of a dc current from ions produced in a surface ionization detector for particulates in combination with simultaneous particulate counting to differentiate between particulates above or below a predetermined size and total particulates present thus determining whether a given aerosol consists primarily of large particulates or very small particulates and providing general information about the particle size in an aerosol. The dc current measurement further provides surface ionization detection of particulates at densities which overload circuitry for pulse counting, whereby the dynamic range of the instrument is extended.
Inventors
- 👤 Wade L. Fite
- 👤 Richard L. Myers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:47
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/025
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
83 words
A method for detecting and measuring particulate matter which comprises the impinging of said particulate matter upon a hot surface whereupon said individual particulates of said particulate matter decompose at the high temperature of the heated surface into fragments, at least some of said fragments being surface ionizable by said hot surface evolving therefrom as bursts of ions, and discerning said bursts of ions so produced by the simultaneous counting of said bursts of ions and the measuring of total current produced thereby.
Claim 2
Independent Claim
83 words
A method for detecting and measuring particulate matter which comprises the impinging of said particulate matter upon a hot surface whereupon said individual particulates of said particulate matter decompose at the high temperature of the heated surface into fragments, at least some of said fragments being surface ionizable by said hot surface evolving therefrom as bursts of ions, and discerning said bursts of ions so produced by the simultaneous counting of said bursts of ions and the measuring of total current produced thereby.
Claim 3
Dependent Claim
24 words
A method in accordance with claim 1 wherein electric fields are provided to attract said ions evolved from said hot surface to an electrode.
Claim 4
Dependent Claim
29 words
A method in accordance with claim 1 wherein electric fields are provided to attract said ions evolved from said hot surface to the first dynode of an electron multiplier.
Claim 5
Dependent Claim
29 words
A method in accordance with claim 1 wherein said particulates which produce bursts of ions which are counted each have a size greater than about 0.4 microns in diameter.
Claim 6
Dependent Claim
28 words
A method in accordance with claim 1 wherein said particulates which produce bursts of ions which are counted each have a mass in excess of 10 3 amu.
Claim 7
Dependent Claim
33 words
A method in accordance with claim 5 wheren said particulates which produce bursts of ions which are counted each have a mass in the range of about 10 4 to 10 8 amu.
Claim 8
Dependent Claim
21 words
A method in accordance with claim 1 wherein a clean gas is used to dilute the gas containing the particulate matter.
Claim 9
Independent Claim
96 words
An apparatus for the detection of particulate matter contained in air, the apparatus comprising a container including a small orifice therein receiving said particulate matter entrained in air, a heated surface in said container arranged so that particulate matter entering said container through said orifice impinges on said heated surface, said heated surface adapted to produce a burst of ions through surface-ionization upon the impingement and decomposition thereon of one of said particulates of said particulate matter, and means for receiving and registering the electric current produced by said bursts of ions on a continuing basis.
Claim 10
Independent Claim
96 words
An apparatus for the detection of particulate matter contained in air, the apparatus comprising a container including a small orifice therein receiving said particulate matter entrained in air, a heated surface in said container arranged so that particulate matter entering said container through said orifice impinges on said heated surface, said heated surface adapted to produce a burst of ions through surface-ionization upon the impingement and decomposition thereon of one of said particulates of said particulate matter, and means for receiving and registering the electric current produced by said bursts of ions on a continuing basis.
Claim 11
Dependent Claim
18 words
Apparatus in accordance with claim 8 wherein said heated surface is heated by an electric current passing therethrough.
Claim 12
Dependent Claim
38 words
Apparatus in accordance with claim 8 wherein said means for receiving and registering the electric current due to all said particulate matter also includes means for receiving and registering the electric charge produced by each burst of ions.
Claim 13
Dependent Claim
32 words
Apparatus in accordance with claim 10 wherein said means for registering the electric charge includes a pulse height discriminator adapted to discriminate pulses generated by ions of a said burst of ions.
Claim 14
Dependent Claim
17 words
Apparatus in accordance with claim 8 wherein a dc current meter is provided to measure said current.
Claim 15
Dependent Claim
36 words
Apparatus in accordance with claim 8 wherein an electron multiplier is provided between said heated surface and said means for receiving and registering said electric current whereby the current produced by bursts of ions is increased.
Claim 16
Dependent Claim
24 words
Apparatus in accordance with claim 8 which includes means for registering said bursts of ions individually simultaneously with the registration of said electric current.
Claim 17
Dependent Claim
20 words
Apparatus in accordance with claim 8 including means for diluting the gas containing said particulate matter with a clean gas.
Claim 18
Dependent Claim
26 words
Apparatus in accordance with claim 8 wherein the pressure in said container is in a range from substantially atmospheric pressure to 10 -4 torr or less.
Claim 19
Dependent Claim
23 words
Apparatus in accordance with claim 8 wherein a blower is provided, said blower moving particulate matter entrained with air into said small orifice.
Claim 20
Independent Claim
129 words
An apparatus for the detection of particulate matter contained in a gas, the apparatus comprising a container including a small orifice therein for receiving said particulate matter entrained in said gas, a heated surface in said container arranged so that the particulate matter entering said container through said orifice impinges on said heated surface, said heated surface adapted to produce a burst of ions through surface-ionization upon the impingement and decomposition thereon of one of said particulate matter, means for analyzing said ions in said burst on the basis of their mass-to-charge ratios, and means for receiving and registering substantially each pulse count and the electric current produced by each said burst of ions which have been analyzed on the basis of their mass-to-charge ratio on a continuing basis.
Claim 21
Independent Claim
129 words
An apparatus for the detection of particulate matter contained in a gas, the apparatus comprising a container including a small orifice therein for receiving said particulate matter entrained in said gas, a heated surface in said container arranged so that the particulate matter entering said container through said orifice impinges on said heated surface, said heated surface adapted to produce a burst of ions through surface-ionization upon the impingement and decomposition thereon of one of said particulate matter, means for analyzing said ions in said burst on the basis of their mass-to-charge ratios, and means for receiving and registering substantially each pulse count and the electric current produced by each said burst of ions which have been analyzed on the basis of their mass-to-charge ratio on a continuing basis.
Claim 22
Dependent Claim
25 words
Apparatus in accordance with claim 18 wherein said means for analyzing said ions on the basis of their mass-to-charge ratio is a quadrupole mass spectrometer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |