Estimation of toxic substance release

• US 20020169557A1
• Filed: 03/15/2002
• Published: 11/14/2002
• Est. Priority Date: 04/18/2001
• Status: Active Grant

• Current Assignee: Industrial Scientific Corporation (Fortive Corp.)
• Original Assignee: Techtrac Systems, LLC
• Inventors: Khajehnajafi, Shahryar, Gilbert, Ernest J.
• Granted Patent: US 6,772,071 B2
• Time in Patent Office: Days
• US Class Current: 702/3
• CPC Class Codes: G01N 33/0004 Gaseous mixtures, e.g. polluted air
• CPC Class Codes: G08B 21/14 Toxic gas alarms G08B21/16 takes precedence

Abstract

A method and system for estimating an amount of a substance, such as a toxic chemical, being released into an ambient thereby creating a plume, includes making multiple concentration measurements of the substance, such as with at least one sensor adapted to be positioned at the plume, at multiple times. The amount of the substance released is estimated as a function of the multiple concentration measurements and the times of the measurements.

Claims

1. A method of estimating an amount of a substance being released into an ambient thereby creating a plume, comprising:

making multiple concentration measurements of the substance at at least one location and at multiple times;

estimating an amount of the substance released as a function of said multiple concentration measurements and said times of the measurements.

2. The method of claim 1 wherein said providing an estimate includes considering atmospheric conditions of the ambient into which the substance was released.

3. The method of claim 2 wherein said considering atmospheric conditions includes considering atmospheric conditions at said times.

4. The method of claim 2 wherein said considering atmospheric conditions includes providing at least one weather sensor adapted to measure atmospheric conditions of the ambient into which the substance was released.

5. The method of claim 2 wherein said considering atmospheric conditions includes downloading weather data from a global network.

6. The method of claim 2 wherein said considering atmospheric conditions includes downloading weather data from a government dial-up weather service.

7. The method of claim 2 wherein said considering atmospheric conditions includes estimating weather by a weather professional.

8. The method of claim 1 wherein said making concentration measurements comprises providing at least one sensor that is adapted to measure a concentration of the substance and positioning said at least one sensor where it is predicted that said at least one sensor will come into contact with the plume.

9. The method of claim 8 wherein said at least one sensor is a sensor chosen from a stationary sensor and a portable sensor.

10. The method of claim 9 wherein said at least one sensor is a wireless portable sensor.

11. The method of claim 9 wherein said at least one sensor is a portable sensor and including repositioning said at least one sensor during the release of the substance.

12. The method of claim 11 including discontinuing measurements during said repositioning and resuming making measurements after said repositioning.

13. The method of claim 9 wherein said at least one sensor is a portable sensor and including positioning said portable sensor at a beginning of the substance release.

14. The method of claim 8 including determining that a particular measurement with a particular one of said at least one sensor is a valid measurement and projecting said particular measurement back in time to obtain a concentration measurement for said particular one of said at least one sensor prior to said valid measurement.

15. The method of claim 14 including projecting said particular measurement back in time to when said particular one of said at least one sensor first was impacted by the plume.

16. The method of claim 8 including determining that a particular measurement with a particular one of said at least one sensor is a maximum measurement and not using future measurements with said particular one of said at least one sensor that occur after said maximum measurement.

17. The method of claim 1 wherein said estimating includes providing a predicted profile of time and concentration measurements and comparing said concentration measurements with the predicted profile.

18. The method of claim 17 including revising said predicted profile in response to said comparing.

19. The method of claim 18 including determining that the concentration measurements have converged with the predicted profile.

20. The method of claim 1 including making multiple measurements in each of multiple different locations and estimating the amount of the substance released as a function of said multiple concentration measurements at each of said locations and times of the measurements.

21. The method of claim 20 wherein said estimating includes adjusting said measurements for travel time of the plume.

22. A substance release rate estimation system for estimating an amount of substance released from a plume created by the release, comprising:

at least one sensor adapted to be positioned at the plume, said at least one sensor measuring concentration of the released substance;

an atmospheric conditions input adapted to inputting atmospheric conditions of the ambient into which the substance was released; and

a computer-based analyzer being programmed with an algorithm, said analyzer receiving multiple concentration measurements from said at least one sensor at multiple times and atmospheric conditions from said atmospheric conditions input, said algorithm generating an estimate of a substance release from said concentration measurements and said atmospheric conditions.

23. The system of claim 22 wherein said atmospheric conditions input considers atmospheric conditions at said times.

24. The system of claim 22 wherein said atmospheric conditions input includes at least one weather sensor adapted to measure atmospheric conditions of the ambient into which the substance was released.

25. The system of claim 22 wherein said atmospheric conditions input downloads weather data from a global network.

26. The system of claim 22 wherein said atmospheric conditions input downloads weather data from a government dial-up weather service.

27. The system of claim 22 wherein said atmospheric conditions input receives weather estimates from a weather professional.

28. The system of claim 22 wherein said at least one sensor is positioned where it is predicted that said at least one sensor will come into contact with a plume.

29. The system of claim 22 wherein said at least one sensor is a sensor chosen from a stationary sensor and a portable sensor.

30. The system of claim 22 wherein said at least one sensor is a wireless portable sensor.

31. The system of claim 30 wherein said at least one sensor is a portable sensor that is adapted to be repositioned during the release of the substance.

32. The system of claim 31 wherein said concentration measurements are suspended while said portable sensor is being repositioned and resumed after said repositioning.

33. The system of claim 22 wherein said at least one sensor is a portable sensor and is adapted to be positioned at a beginning of the substance release.

34. The system of claim 22 wherein said analyzer determines that a particular measurement with a particular one of said at least one sensor is a valid measurement and projecting said particular measurement back in time to obtain a concentration measurement for said particular one of said at least one sensor prior to said valid measurement.

35. The system of claim 34 wherein said analyzer projects said particular measurement back in time to when said particular one of said at least one sensor first was impacted by the plume.

36. The system of claim 22 wherein said analyzer determines that a particular measurement with a particular one of said at least one sensor is a maximum measurement and not using future measurements with said particular one of said at least one sensor that occur after said maximum measurement.

37. The system of claim 22 wherein said algorithm generates said estimate by predicting a profile of time and concentration measurements and comparing said concentration measurements with the predicted profile.

38. The system of claim 37 wherein said algorithm revises said predicted profile in response to said comparing.

39. The system of claim 38 wherein said algorithm determines that the concentration measurements have converged with the predicted profile.

40. The system of claim 22 wherein multiple measurements are made in each of multiple different locations and the amount of the substance released is estimated as a function of said multiple concentration measurements at each of said locations and times of the measurements.

41. The system of claim 40 wherein said estimates are adjusted for travel time of the plume.

42. A substance release estimation system for estimating an amount of released substance, the release of which creates a plume, comprising:

at least one sensor adapted to be positioned at a plume and make multiple concentration measurements of the released substance at multiple times; and

a computer-based analyzer being programmed with an algorithm, said analyzer receiving concentration measurements from said at least one sensor, said algorithm generating an estimate of amount of substance released from said concentration measurements.

43. The system of claim 42 including an atmospheric conditions input that considers atmospheric conditions at said times.

44. The system of claim 43 wherein said atmospheric conditions input includes at least one weather sensor adapted to measure atmospheric conditions of the ambient into which the substance was released.

45. The system of claim 43 wherein said atmospheric conditions input downloads weather data from a global network.

46. The system of claim 43 wherein said atmospheric conditions input downloads weather data from a government dial-up weather service.

47. The system of claim 43 wherein said atmospheric conditions input receives weather estimates from a weather professional.

48. The system of claim 42 wherein said at least one sensor is positioned where it is predicted that said at least one sensor will come into contact with a plume.

49. The system of claim 42 wherein said at least one sensor is a sensor chosen from a stationary sensor and a portable sensor.

50. The system of claim 42 wherein said at least one sensor is a wireless portable sensor.

51. The system of claim 50 wherein said at least one sensor is a portable sensor that is adapted to be repositioned during the release of the substance.

52. The system of claim 51 wherein said concentration measurements are suspended while said portable sensor is being repositioned and resumed after said repositioning.

53. The system of claim 42 wherein said at least one sensor is a portable sensor and is adapted to be positioned at a beginning of the substance release.

54. The system of claim 42 wherein said analyzer determines that a particular measurement with a particular one of said at least one sensor is a valid measurement and projecting said particular measurement back in time to obtain a concentration measurement for said particular one of said at least one sensor prior to said valid measurement.

55. The system of claim 54 wherein said analyzer projects said particular measurement back in time to when said particular one of said at least one sensor first was impacted by the plume.

56. The system of claim 42 wherein said analyzer determines that a particular measurement with a particular one of said at least one sensor is a maximum measurement and not using future measurements with said particular one of said at least one sensor that occur after said maximum measurement.

57. The system of claim 42 wherein said algorithm generates said estimate by predicting a profile of time and concentration measurements and comparing said concentration measurements with the predicted profile.

58. The system of claim 57 wherein said algorithm revises said predicted profile in response to said comparing.

59. The system of claim 58 wherein said algorithm determines that the concentration measurements have converged with the predicted profile.

60. The system of claim 42 wherein multiple measurements are made in each of multiple different locations and the amount of the substance released is estimated as a function of said multiple concentration measurements at each of said locations and times of the measurements.

61. The system of claim 60 wherein said estimates are adjusted for travel time of the plume.