1 / 28

Open Path Detection of Hazardous Gases

Open Path Detection of Hazardous Gases. Technology Overview. Open path, non-contact chemical detection Multiple chemicals detected and identified by a single detector Rapid detection and identification (<1 sec) Sensitive, specific, reliable and robust

Download Presentation

Open Path Detection of Hazardous Gases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Open PathDetection of Hazardous Gases

  2. Technology Overview • Open path, non-contact chemical detection • Multiple chemicals detected and identified by a single detector • Rapid detection and identification (<1 sec) • Sensitive, specific, reliable and robust • Low maintenance and low cost of ownership Avir Sensors Proprietary

  3. ChemSight™ Architecture Based on infrared spectrometry operating in the 830-1250 cm-1(fingerprint region) 2000-3300 cm-1 spectral ranges Avir Sensors Proprietary

  4. IR Spectrum Parsing IR spectrum absorption curve is parsed into 16 segments Each of the 16 segments is “zeroed out” to create a “background” Chemicals passing through the line of sight absorb known frequencies of IR. The ChemSight accurately detects and identifies the signature across a wide range of concentrations. Avir Sensors Proprietary

  5. Avir Sensors Proprietary

  6. Open Path, Non-contact Chemical Detection • Large coverage area • No contact required for detection and identification and, consequently, no sensor poisoning • Stand off detector does not require predicting potential release areas • Applicable to inaccessible locations • Designated a Department of Homeland Security SAFETY Act Qualified Anti-terrorism Technology (QATT) Avir Sensors Proprietary

  7. Instant Alert and Identification • Patented ChemVECTOR™ algorithm recognizes and identifies chemical’s infrared signatures in one second • Detection and identification confirmed over user-defined intervals (30 seconds typical) • Large on-board database of chemical signatures • User configurable alert and alarm actions • Easily operated by untrained personnel Avir Sensors Proprietary

  8. Selected Hazardous Gases Avir Sensors Proprietary

  9. Sensitive, Specific, Reliable, and Robust • Patented ChemVECTOR™ detection and identification algorithm allows: • Chemical detection and identification well below IDLH • Detection of high and low chemical concentrations • Rejection of background interferants while maintaining trace level sensitivity • Full system verification using on-board confidence tester • Sealed to IP66 standards for continuous operation in harsh environments • Less than 20 watts power consumption Avir Sensors Proprietary

  10. Path Integrated Concentrations Avir Sensors Proprietary

  11. Representative Sensitivities(Over 100 meter path) All units in ppm 1 Second 30 Seconds Avir Sensors Proprietary

  12. Receiver Operating Characteristic(ROC) Curves • ROC curves describe the likelihood of correct dichotomous decisions • a patient has a disease / does not have a disease • an anomaly has been detected / has not been detected • a chemical is present / not present true positive rate: TP/(TP+FN) {probability of identification} false-positive rate: FP/(TN+FP) {probability of false-identification} Avir Sensors Proprietary

  13. Illustrative ROC Curves 1.0 CT brain lesions Mammography screening Diabetes screening Polygraph (police) 0.5 True Positive rate CT brain lesions: AUC 97% mammography: AUC 78-91% diabetes: AUC 81% polygraph: AUC 55-75% 0 False Positive rate 0.5 1.0 Avir Sensors Proprietary

  14. ChemSight™ ROC Curves 75 ppm·m ammonia, 1 sec average Avir Sensors Proprietary

  15. ChemSight™ ROC Curves 75 ppm·m ammonia, 30 sec average Avir Sensors Proprietary

  16. Low Maintenance, Low Ownership Cost • No consumables • No ongoing calibration required • Detector is monitored for blockage, dirt accumulation and other fault diagnosis • Interfaces with standard security software systems • New chemical signatures added to database via software • On-board, full system confidence tester activated at user defined intervals Avir Sensors Proprietary

  17. Typical Applications • Perimeter protection • HVAC systems • Railway platforms • Ports • Airports • Stadiums • Chemical manufacturing and storage facilities • Manufacturing facilities • Environmental monitoring • Schools Avir Sensors Proprietary

  18. Return on Investment Avir Sensors Proprietary

  19. Technology Heritage • Designated a Department of Homeland Security SAFETY Act Qualified Anti-terrorism Technology (QATT) • Metro Rail • Industrial Installations • Carbonated beverage manufacturing • Defense Logistics Agency • Institutional Ventilation Avir Sensors Proprietary

  20. Mahalanobis Distance Technique Avir Sensors Proprietary

  21. Mahalanobis Distance • The Mahalanobis Distance is a mathematical tool that is part of ChemVECTOR™, a patented detection and identification algorithm unique to the ChemSight™. • When a hazardous gas or interferant crosses the IR beam, ChemVECTOR™ determines: • the mathematical magnitude relative to ambient air for detection • the mathematical proximity to signatures in the chemical database for identification Prasanta Chandra Mahalanobis Avir Sensors Proprietary

  22. Mahalanobis Distance Plot Ammonia at 70°F/30% RH, 30 sec averaging Avir Sensors Proprietary

  23. Uniqueness of ChemVECTOR™ • The MD-based mathematics in ChemVECTOR™ allow reliable detection and identification when over a wide range of concentrations even in the presence of a heavy load of interferants. • Unlike alternative algorithms (e.g., principal component analysis - PCA), ChemVECTOR™ allows chemical signatures to be added to the signature database in any combination without recalculating the entire database. • Detection and identification thresholds can be adjusted by ChemVECTOR™. Avir Sensors Proprietary

  24. Physical and Software Schematics Avir Sensors Proprietary

  25. ChemSight™ Detection and Identification Detection Identification Identification occurs when a new signal matches a signature in the library. For positive identification, the match needs to be within a mathematically determined threshold by ChemVECTOR™. When positive detection occurs but the signal is outside the identification threshold the ChemVECTOR™ issues an “Unknown” message. • Detection occurs when a new signal significantly exceeds background noise level. • A mathematical threshold is set to create an acceptable level of false alarms. This threshold defines sensitivity. Avir Sensors Proprietary

  26. ChemSight™ Optical Layout 3) Band pass filters parse spectrum and send signals for processing 1) IR Light Enters Detector 2) Rotating Mirror concentrates light on detector array Internal Layout of ChemSight™ Avir Sensors Proprietary

  27. ChemSight™ Detector Dimensions 7.0” 7.5” 22.5” Avir Sensors Proprietary

  28. ChemSight™ Source Dimensions 14” 14” 8” Avir Sensors Proprietary

More Related