Humidity sensor and method for monitoring moisture in concrete

• US 20070065071A1
• Filed: 06/30/2006
• Published: 03/22/2007
• Est. Priority Date: 06/30/2005
• Status: Abandoned Application

• Current Assignee: Infoscitex
• Original Assignee: Infoscitex
• Inventors: Slade, Jeremiah, Lusignea, Richard, Everson, Jeffrey, Kokkins, Stephan, Kristoff, Susan
• Application Number:
  US11/479,992
• Publication Number:
  US 20070065071A1
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: G01D 5/35303 using a reference fibre, e.g. interferometric devices
• CPC Class Codes: G01M 11/083 by using an optical fiber in contact with the device under test [DUT]
• CPC Class Codes: G01M 3/047 with photo-electrical detection means, e.g. using optical fibres
• CPC Class Codes: G02B 6/022 using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper G02B6/02204 takes precedence; optical modulation using photo-elastic effect G02F1/0131

Abstract

A humidity sensor and method is disclosed. The sensor is configured as an optical fiber based sensor and may be useful in obtaining moisture information, such as humidity and/or relative humidity (RH) in curing concrete. The sensor may be configured to isolate the sensor from external mechanical stresses, chemical reactions and/or temperature fluctuations that may occur in the concrete and/or at least account for such occurrences. Methods of calibrating the sensor are also disclosed. The sensor may be configured as a fiber Bragg sensor.

Claims

1. A method of obtaining humidity data in curing concrete, the method comprising:

providing a fiber optic based humidity sensor;

instructing placing the sensor in concrete during or after concrete is poured and prior to the concrete being fully cured; and

instructing connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of humidity in the concrete as the concrete is curing.

2. The method of claim 1, wherein instructing connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of humidity in the concrete comprises instructing connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of relative humidity in the concrete.

3. The method of claim 1, wherein providing a fiber optic based humidity sensor comprises providing a fiber Bragg grating sensor.

4. The method of claim 3, wherein providing a fiber Bragg grating sensor comprises providing a fiber Bragg grating sensor having a selectively permeable covering adapted to substantially allow water vapor to flow through the covering and substantially prevent liquid water to flow through the covering.

5. The method of claim 4, wherein providing a fiber Bragg grating sensor having a selectively permeable covering comprises providing the fiber Bragg grating sensor with a PTFE covering.

6. The method of claim 1, wherein providing a fiber optic based humidity sensor comprises providing the fiber optic based humidity sensor within a relatively rugged container.

7. The method of claim 6, providing a fiber optic based humidity sensor within the relatively rugged container comprises providing the fiber optic based humidity sensor within a metal sleeve.

8. The method of claim 6, providing a fiber optic based humidity sensor within the relatively rugged container comprises providing the fiber optic based humidity sensor within a porous sleeve.

9. The method of claim 1, further comprising providing a fiber optic based temperature sensor in close proximity to the fiber optic based humidity sensor.

10. The method of claim 9, wherein providing a fiber optic based humidity sensor comprises providing an optical fiber and wherein providing a fiber optic based temperature sensor in close proximity to the fiber optic based humidity sensor comprises providing the fiber optic based temperature sensor on the optical fiber.

11. The method of claim 1, wherein providing a fiber optic based humidity sensor comprises providing a pre-packaged fiber optic based humidity sensor that is packaged in a relatively high humidity package and thereafter instructing removal of the fiber optic based sensor from the package prior to placing the sensor in concrete.

12. The method of claim 1, wherein providing a fiber optic based humidity sensor comprises providing a plurality of fiber optic based humidity sensors;

and wherein

instructing placing the sensor in concrete during or after concrete is poured comprises instructing placing the plurality of sensors in concrete in an array.

13. A method of obtaining humidity data in curing concrete, the method comprising:

obtaining a fiber optic based humidity sensor;

placing the sensor in concrete during or after concrete is poured and prior to the concrete being fully cured; and

connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of humidity in the concrete as the concrete is curing.

14. The method of claim 13, wherein connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of humidity in the concrete comprises connecting the sensor to a reader that is adapted to obtain a signal from the sensor indicative of relative humidity in the concrete.

15. The method of claim 13, wherein obtaining a fiber optic based humidity sensor comprises providing a fiber Bragg grating sensor.

16. The method of claim 15, wherein obtaining a fiber Bragg grating sensor comprises obtaining a fiber Bragg grating sensor having a selectively permeable covering adapted to substantially allow water vapor to flow through the covering and substantially prevent liquid water to flow through the covering.

17. The method of claim 16, wherein obtaining a fiber Bragg grating sensor having a selectively permeable covering comprises obtaining the fiber Bragg grating sensor with a PTFE covering.

18. The method of claim 13, wherein obtaining a fiber optic based humidity sensor comprises obtaining the fiber optic based humidity sensor within a relatively rugged container.

19. The method of claim 18, obtaining a fiber optic based humidity sensor within the relatively rugged container obtaining the fiber optic based humidity sensor within a metal sleeve.

20. The method of claim 18, obtaining a fiber optic based humidity sensor within the relatively rugged container comprises obtaining the fiber optic based humidity sensor within a porous sleeve.

21. The method of claim 13, further comprising obtaining a fiber optic based temperature sensor in close proximity to the fiber optic based humidity sensor.

22. The method of claim 21, wherein obtaining a fiber optic based humidity sensor comprises obtaining an optical fiber and wherein obtaining a fiber optic based temperature sensor in close proximity to the fiber optic based humidity sensor comprises obtaining the fiber optic based temperature sensor on the optical fiber.

23. The method of claim 13, wherein providing a fiber optic based humidity sensor comprises obtaining a pre-packaged fiber optic based humidity sensor that is packaged in a relatively high humidity package and thereafter removing the fiber optic based sensor from the package prior to placing the sensor in concrete.

24. The method of claim 13, wherein obtaining a fiber optic based humidity sensor comprises obtaining a plurality of fiber optic based humidity sensors;

and wherein placing the sensor in concrete during or after concrete is poured comprises placing the plurality of sensors in concrete in an array.