http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CA-2009226-A1
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_51918c020af30e1d6344838140d7caf5 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G01N21-27 |
| filingDate | 1990-02-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_813ff9d49b9cd8f118a7fa43434ac9e5 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_089b41534147dd97e9f022a9f4e93cd8 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_2364d8bf75a72432d1f7aa202c3f2b3d http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_37028035176047a5aac0f1d6229e0ed3 |
| publicationDate | 1991-08-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | CA-2009226-A1 |
| titleOfInvention | Fiber optic sensors |
| abstract | ABSTRACT OF THE DISCLOSURE Several improvements in fiber optic sensing systems are disclosed. One improvement incorporates a dielectric filter applied directly to the sensing end of an optical fiber detector which has the characteristic that it reflects back a reference light beam of one wavelength while passing a sensing signal of a different wavelength which is modulated in some predetermined fashion beyond the filter. Both light signals are reflected back through the fiber and are, accordingly, attenuated in an identical or nearly identical fashion in response to various noise sources. The ratio of the intensity of the two signals is proportional to the sensed parameter and renders the system essentially self-compensating. The dielectric filter is preferably directly coated onto the exit end of the fiber through vapor deposition techniques. Time division multiplexing is used to sequentially fire plural light sources and a single photodetector is used for measuring the intensity of the reflected back signals of the various wavelengths. Another improvement encompasses the detection unit in which the input and reflected signals are separated using an off-axis parabolic mirror which provides excellent separation efficiency. According to another principal feature of this invention, a concave surface is formed at the fiber end which increases the numerical aperture of the fiber which provides greater sensitivity to the deflection of a pressure sensitive diaphragm spaced from and confronting the fiber end. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-111494743-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/CN-111494743-B |
| priorityDate | 1990-02-02-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 19.