Self adjusting sensor mounting device

• US 20050193839A1
• Filed: 03/05/2004
• Published: 09/08/2005
• Est. Priority Date: 03/05/2004
• Status: Active Grant

• Current Assignee: Aber Instruments, Inc.
• Original Assignee: BugLab LLC
• Inventors: Gronvall, Daniel
• Granted Patent: US 7,100,462 B2
• Time in Patent Office: Days
• US Class Current: 73/866.5
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01N 2291/101 one transducer
• CPC Class Codes: G01N 29/223 Supports, positioning or alignment in fixed situation mounting transducers per se G10K11/004

Abstract

A method and device for mounting a sensor to a surface that is flat in one dimension and flat or curved in a second dimension. The mounting method results in stable self-centering attachment of the sensor to the surface across a wide range of radii in the second dimension of the surface. A fixed distance and angle between the sensor components and the surface is automatically maintained despite wide changes in the radius of the surface. An attachment means is provided that is secure, repeatable, and reusable. Additionally, a means of maintaining a clear unobstructed window between the sensor and surface is provided.

Claims

1. A device for attaching a sensor to a surface, said surface being substantially flat in a first dimension and curved or flat in a second dimension, comprising:

a) an inner housing containing said sensor, said sensor including at least one component emitting electromagnetic or acoustic radiation and at least one component detecting electromagnetic or acoustic radiation;

b) an outer housing providing a means of stably mounting said sensor to said surface that automatically accommodates variable radii of said second dimension of said surface, and is substantially self-centering about at least one axis with respect to said surface when said second dimension of said surface is curved;

c) a means of attaching said inner housing to said outer housing that self-adjusts to different radii of said second dimension of said surface, wherein a fixed geometric relationship is maintained between each of the sensor components and the nearest point on said surface,

whereby said sensor is stably attached to a wide variety of surfaces in a manner that provides automatic compensation for the curvature of said surfaces.

2. The device of claim 1 wherein said means of stably mounting includes a V-notched shape in said outer housing.

3. The device of claim 1 wherein said means of stably mounting includes a U-notched shape in said outer housing.

4. The device of claim 1 wherein said means of attaching said inner housing to said outer housing includes a spring.

5. The device of claim 1 wherein said fixed geometric relationship includes at least one predetermined distance between at least one of said sensor components and said nearest point on said surface.

6. The device of claim 4 including a means of adjusting said predetermined distances between said sensor components and said surface.

7. The device of claim 1 wherein said fixed geometric relationship includes at least one predetermined angle between at least one of said sensor components and said nearest point on said surface.

8. The device of claim 7 including a means of adjusting said predetermined angle between said sensor components and said surface.

9. The device of claim 1 wherein said sensor components are all disposed within the same plane.

10. The device of claim 9 wherein said plane is parallel to said second dimension of said surface when the sensor is mounted to the surface.

11. The device of claim 1 wherein one of the self-centering axes is perpendicular to the mounting surface.

12. The device of claim 1 wherein one of the self-centering axes is parallel to said first dimension of said surface.

13. The device of claim 1 wherein said surface is the exterior surface of a container.

14. The device of claim 1 wherein said surface is the interior surface of a container.

15. The device of claim 1 wherein said outer housing is mounted to said surface by means of a strap looped around the circumference of said surface.

16. The device of claim 15 providing an additional strap as a means of extending the length of the first said strap.

17. The device of claim 15 including at least one means of applying tension to said strap so that said sensor is fixedly and reproducibly secured to said surface.

18. The device of claim 17 wherein said means of applying tension comprises a first means of loosely tensioning said strap onto said surface and a second means of tightly tensioning said strap onto said surface.

19. The device of claim 18 wherein said first means is a buckle and said second means is a latch.

20. The device of claim 1 wherein a material that is transparent to said radiation is used to fill a gap between said sensor and said surface.

21. The device of claim 20 wherein said material is an index-matching gel.

22. The device of claim 1 wherein said surface is part of a fermenter or bioreactor.

23. The device of claim 22 wherein said sensor components are arranged so that reflectance from the interior of said fermenter or bioreactor is measured.

24. The device of claim 23 wherein said reflectance is used as an indication of biomass in said fermenter or bioreactor.

25. The device of claim 1 wherein said light emitting devices emit light in the near infrared region of the spectrum.

26. The device of claim 1 wherein said inner housing includes both a compressible member and an incompressible member that surround a face of said sensor, arranged such that when said sensor is attached to said surface, said compressible member is compressed until said incompressible member contacts said mounting surface, thereby providing a seal between said surface and said face of said sensor without affecting said fixed geometric relationship.

27. The device of claim 26 wherein said compressible member also provides a means of gripping the mounting surface.

28. The device of claim 1 wherein a means is provided for sealing said inner housing against the surrounding environment.

29. The device of claim 1 wherein said inner housing includes a means of traveling across said surface with low friction.

30. The device of claim 1 wherein said outer housing is attached to said surface using adhesive.

31. The device of claim 1 wherein a permanent fixture is attached to said surface, said fixture providing a means of securely attaching said outer housing to said surface.

32. A method of attaching a sensor to a surface, said surface being substantially flat in a first dimension and curved or flat in a second dimension, which comprises the steps of:

a) surrounding said surface with a strap that is attached to an outer housing, said outer housing also being attached to an inner housing containing said sensor;

b) forming a closed loop around said surface comprising said strap and said outer housing;

c) tensioning said closed loop, thereby urging both said outer housing and said inner housing against said surface, thereby resulting in;

(1) said outer housing self-centering about at least one axis with respect to said surface when said second dimension of said surface is curved, and

(2) said inner housing self-adjusting to different radii of said second dimension of said surface, wherein a fixed geometric relationship is maintained between each of the sensor components and the nearest point on said surface,

whereby said sensor is stably attached to a wide variety of surfaces in a manner that provides automatic compensation for the curvature of said surfaces.

33. The method of claim 32 wherein said closed loop is formed using a buckle.

34. The method of claim 33 wherein said tensioning of said closed loop is performed by a method that includes pulling said strap through said buckle.

35. The method of claim 34 wherein said tensioning of said closed loop is performed by a method that further includes closing a latch.