US5818047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detector for explosive substances
Assignee: Renishaw PLC
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Filing: 1995-08-21
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Granted: 1998-10-06
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Expires: 2015-08-21
Abstract
Abstract The presence of Semtex plastic explosive in a sample such as a fingerprint is detected by Raman spectroscopy. RDX and PETN, the active chemical ingredients of Semtex, have strong Raman peaks at 885 cm -1 and 874 cm -1 respectively. Consequently, both these peaks can be detected in a Raman spectroscopic system by employing a filter having a narrow passband centered on 880 cm -1 and with a bandwidth of 20 cm -1 . Such a filter is used in a Raman system used to scan airport boarding cards, or in a Raman microscope which produces images of fingerprints.
Inventors
- 👤 Raymond J Chaney
- 👤 David N Batchelder
- 👤 Richard J Lacey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:34
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/65; G01N21/658
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
92 words
Apparatus for detecting an explosive material in a sample, comprising: a light source for illuminating the sample to cause the production of Raman scattered light; a detector for detecting Raman scattered light received from the sample; and a filter between the sample and the detector, the filter passing to the detector only light in a band which includes 874 cm -1 and 885 cm -1 , said band being sufficiently narrow that light substantially greater than 885 cm -1 or substantially less than 874 cm -1 is not passed to the detector.
Claim 2
Dependent Claim
92 words
Apparatus for detecting an explosive material in a sample, comprising: a light source for illuminating the sample to cause the production of Raman scattered light; a detector for detecting Raman scattered light received from the sample; and a filter between the sample and the detector, the filter passing to the detector only light in a band which includes 874 cm -1 and 885 cm -1 , said band being sufficiently narrow that light substantially greater than 885 cm -1 or substantially less than 874 cm -1 is not passed to the detector.
Claim 3
Dependent Claim
28 words
Apparatus according to claim 1, wherein the sample is in the form of a document, an area of which is scanned by the light source, detector and filter.
Claim 4
Dependent Claim
18 words
Apparatus according to claim 2, in which the document is transported past the light source, detector and filter.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 2, including a lens arranged to produce a line focus of light from the light source across the document.
Claim 6
Dependent Claim
21 words
Apparatus according to claim 2, including a device which scans a spot of light from the light source across the document.
Claim 7
Dependent Claim
11 words
Apparatus according to claim 2, wherein said document is a card.
Claim 8
Dependent Claim
18 words
Apparatus according to claim 1, wherein the detector detects a two-dimensional image of an area of the sample.
Claim 9
Dependent Claim
20 words
Apparatus according to claim 1, including means for detecting a spectrum of Raman scattered light, in addition to said filter.
Claim 10
Dependent Claim
24 words
Apparatus according to claim 1, wherein the filter has a bandwidth of about 20 cm -1 , centred on about 880 cm -1 .
Claim 11
Independent Claim
95 words
A method for detecting an explosive material in a sample, comprising: illuminating the sample with a light source to cause the production of Raman scattered light; detecting the Raman scattered light received from the sample with a detector, wherein a filter is placed between the sample and the detector to pass to the detector only light in a band which includes 874 cm -1 and 885 cm -1 , the band being sufficiently narrow that light substantially greater than 885 cm -1 or substantially less than 874 cm -1 is not passed to the detector.
Claim 12
Independent Claim
95 words
A method for detecting an explosive material in a sample, comprising: illuminating the sample with a light source to cause the production of Raman scattered light; detecting the Raman scattered light received from the sample with a detector, wherein a filter is placed between the sample and the detector to pass to the detector only light in a band which includes 874 cm -1 and 885 cm -1 , the band being sufficiently narrow that light substantially greater than 885 cm -1 or substantially less than 874 cm -1 is not passed to the detector.
Claim 13
Dependent Claim
29 words
A method according to claim 10, wherein the sample is in the form of a document, an area of which is scanned by the light source, detector and filter.
Claim 14
Dependent Claim
19 words
A method according to claim 11, in which the document is transported past the light source, detector and filter.
Claim 15
Dependent Claim
25 words
A method according to claim 10, wherein the filter has a bandwidth of about 20 cm -1 , centered on about 880 cm -1 .
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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) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |