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Patent US5369369A successfully refreshed from Google Patents.
US5369369A
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Determination of carbon in a fly ash sample through comparison to a reference microwave attenuation and phase shift
Assignee: Commonwealth Scientific and Industrial Research Organisation
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Filing: 1991-03-20
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Granted: 1994-11-29
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Expires: 2011-03-20
Abstract
Abstract PCT No. PCT/AU91/00108 Sec. 371 Date Sep. 14, 1992 Sec. 102(e) Date Sep. 14, 1992 PCT Filed Mar. 20, 1991 PCT Pub. No. WO91/14936 PCT Pub. Date Oct. 3, 1991.An apparatus and method to measure the unburnt carbon content of fly ash. A microwave signal is transmitted through or reflected from a fly ash sample and the attenuation or phase shift of the signal received by a detector/detectors is determined with respect to the incident signal and is used to provide a measure of unburnt carbon content. The detectors may be antennae means which also launch the incident signal or may be a completely separate means. A preferred embodiment comprises a microwave oscillator for launching the microwave signal into a fly ash sample in a microwave resonant cavity. Detectors determine the attenuation of phase shift of the received signal with respect to a signal from a reference microwave resonant cavity by the fly ash sample, and a measurement of the unburnt carbon content is obtained.
Inventors
- 👤 Nicholas G. Cutmore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:47
CPC Classifications
G; G01; G01N; G01N22/00
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
97 words
An apparatus to measure the unburnt carbon content of a fly ash sample comprising: a reference chamber; a measurement chamber for measurement of the fly ash sample; means to generate a microwave signal; transmitter means to launch the microwave signal for transmission through the reference chamber and the fly ash sample; receiver means to receive a signal passed through the sample; and processing means for determining the attenuation and phase shift of the signal passed through the sample and the reference chamber with respect to the launched signal and for producing a measure of unburnt carbon content.
Claim 2
Independent Claim
97 words
An apparatus to measure the unburnt carbon content of a fly ash sample comprising: a reference chamber; a measurement chamber for measurement of the fly ash sample; means to generate a microwave signal; transmitter means to launch the microwave signal for transmission through the reference chamber and the fly ash sample; receiver means to receive a signal passed through the sample; and processing means for determining the attenuation and phase shift of the signal passed through the sample and the reference chamber with respect to the launched signal and for producing a measure of unburnt carbon content.
Claim 3
Independent Claim
87 words
An apparatus to measure the unburnt carbon content of a fly ash sample comprising: means to generate a microwave signal; antennae means to launch the microwave signal into the fly ash sample, and to receive a reflected signal; and processing means for determining the attenuation and phase shift of the reflected signal with respect to the launched signal, and for measuring the unburnt carbon content of the fly ash, and means for determining a reference measurement of the attenuation and phase shift without the fly ash sample.
Claim 4
Independent Claim
87 words
An apparatus to measure the unburnt carbon content of a fly ash sample comprising: means to generate a microwave signal; antennae means to launch the microwave signal into the fly ash sample, and to receive a reflected signal; and processing means for determining the attenuation and phase shift of the reflected signal with respect to the launched signal, and for measuring the unburnt carbon content of the fly ash, and means for determining a reference measurement of the attenuation and phase shift without the fly ash sample.
Claim 5
Dependent Claim
21 words
The apparatus as claimed in claim 1 wherein at least one of the transmitter means and the receiver means include antenna.
Claim 6
Dependent Claim
23 words
The apparatus as claimed in claim 2 wherein the antennae means include a single antenna for both launching and receiving the microwave signal.
Claim 7
Dependent Claim
16 words
The apparatus as claimed in claim 3, wherein the measurement chamber contains the fly ash sample.
Claim 8
Dependent Claim
24 words
The apparatus as claimed in claim 5 wherein the antenna include horn antenna and the measurement chamber includes a material permitting transmission of microwaves.
Claim 9
Dependent Claim
23 words
The apparatus as claimed in claim 5 wherein the antenna include inductive loop antenna and the measurement chamber is a section of waveguide.
Claim 10
Dependent Claim
23 words
The apparatus as claimed in claim 5 wherein the antenna include inductive loop antenna and the measurement chamber is a section of waveguide.
Claim 11
Dependent Claim
14 words
The apparatus as claimed in claim 2 wherein the antenna means include inductive loops.
Claim 12
Dependent Claim
15 words
The apparatus as claimed in claim 2 wherein the antenna means include capacitive post antenna.
Claim 13
Dependent Claim
16 words
The apparatus as claimed in claim 5 wherein the measurement chamber includes a microwave resonant cavity.
Claim 14
Dependent Claim
17 words
The apparatus as claimed in claim 11 wherein the microwave resonant cavity operates in a TE mode.
Claim 15
Dependent Claim
17 words
The apparatus as claimed in claim 11 wherein the microwave resonant cavity operates in a TM mode.
Claim 16
Dependent Claim
22 words
The apparatus as claimed in claim 11 wherein the fly ash sample is disposed about an axis of the microwave resonant cavity.
Claim 17
Dependent Claim
19 words
The apparatus as claimed in claim 2 wherein the microwave signal is launched and received by a microwave transceiver.
Claim 18
Dependent Claim
45 words
The apparatus as claimed in claim 15 further comprising a microwave reflector disposed on the distal side of the fly ash sample to the antenna means to reflect the microwave signal passed through the fly ash sample back through the sample to the antenna means.
Claim 19
Dependent Claim
45 words
The apparatus as claimed in claim 1 wherein the measurement chamber includes a microwave resonant cavity, and the processing means determines a change in the characteristics of the resonant cavity induced by the fly ash sample and produces therefrom the measure of unburnt carbon content.
Claim 20
Dependent Claim
40 words
The apparatus as claimed in claim 17 wherein the change in the characteristics are determined by comparing the signal received by the receiver means with a reference signal obtained from a measurement of the reference chamber not containing the sample.
Claim 21
Independent Claim
68 words
A method of measuring the unburnt carbon content of a fly ash sample comprising the steps of: launching a microwave signal into a reference chamber and a measurement chamber containing the fly ash sample, receiving the microwave signal; determining the attenuation and phase shift of the received signal with respect to the launched signal; and producing a measure of unburnt carbon content from the attenuation and phase shift.
Claim 22
Independent Claim
68 words
A method of measuring the unburnt carbon content of a fly ash sample comprising the steps of: launching a microwave signal into a reference chamber and a measurement chamber containing the fly ash sample, receiving the microwave signal; determining the attenuation and phase shift of the received signal with respect to the launched signal; and producing a measure of unburnt carbon content from the attenuation and phase shift.
Claim 23
Independent Claim
83 words
A method of measuring the unburnt carbon content of a fly ash sample comprising the steps of: launching a microwave signal into the fly ash sample; receiving a component of the signal reflected from the fly ash sample; determining the attenuation and phase shift of the reflected signal with respect to the launched signal; correlating a measure of unburnt carbon content with the attenuation and phase shift; and determining a reference measurement of the attenuation and phase shift without the fly ash sample.
Claim 24
Independent Claim
83 words
A method of measuring the unburnt carbon content of a fly ash sample comprising the steps of: launching a microwave signal into the fly ash sample; receiving a component of the signal reflected from the fly ash sample; determining the attenuation and phase shift of the reflected signal with respect to the launched signal; correlating a measure of unburnt carbon content with the attenuation and phase shift; and determining a reference measurement of the attenuation and phase shift without the fly ash sample.
Claim 25
Dependent Claim
20 words
The method as claimed in claim 19 including transmitting the microwave signal into the fly ash sample in free space.
Claim 26
Dependent Claim
16 words
The method as claimed in claim 19 including disposing the fly ash sample in a waveguide.
Claim 27
Dependent Claim
18 words
The method as claimed in claim 19 including disposing the fly ash sample in a microwave resonant cavity.
Claim 28
Dependent Claim
17 words
The method as claimed in claim 23 including operating the microwave resonant cavity in a TE mode.
Claim 29
Dependent Claim
17 words
The method as claimed in claim 23 including operating the microwave resonant cavity in a TM mode.
Claim 30
Dependent Claim
38 words
The method as claimed in claim 23 including determining the measure of the unburnt carbon content of the fly ash sample from a change in the characteristics of the microwave resonant cavity induced by the fly ash sample.
Claim 31
Dependent Claim
33 words
The method as claimed in claim 26 including determining the change in the characteristics of the microwave resonant cavity by comparing the received signal with a reference signal passed through the reference chamber.
Claim 32
Dependent Claim
17 words
The apparatus as claimed in claim 1 wherein the transmitter means and the receiver means include antenna.
Claim 33
Dependent Claim
36 words
The apparatus as claimed in claim 1 wherein the processing means determines the change in the characteristics of the resonant cavity induced by the fly ash sample and produces therefrom the measure of unburnt carbon content.
Claim 34
Dependent Claim
20 words
The method as claimed in claim 15 including transmitting the microwave signal into the fly ash sample in free space.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-28 | 1998-05-30 | 1998-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-28 | 2002-05-30 | 2002-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-28 | 2006-05-30 | 2006-11-29 | $7700.00 | Window Closed / Lapsed |