MOISTURE DETECTION SENSORS FOR BUILDING STRUCTURES

• US 20120074967A1
• Filed: 12/01/2011
• Published: 03/29/2012
• Est. Priority Date: 07/18/2003
• Status: Abandoned Application

• Current Assignee: Detec Systems LLC
• Original Assignee: Detec Systems LLC
• Inventors: Vokey, David E., Nassar, Hani, Coburn, James Gary, Wells, Jody Aaaron
• Application Number:
  US13/309,010
• Publication Number:
  US 20120074967A1
• Time in Patent Office: Days
• US Class Current: 324/696
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G01N 27/048 for determining moisture content of the material
• CPC Class Codes: G01N 33/46 Wood

Abstract

A moisture detection sensor is used in a building structure to detect moisture penetration is a flat self-adhesive tape. It includes a substrate of dielectric, hydrophobic material. Two elongate, parallel, conductors are secured to the top surface and a protective layer of non-hygroscopic, water pervious material secured over the conductors. A pressure sensitive adhesive on a bottom surface of the substrate is covered with a release sheet. The sensor may include moisture probes which penetrate the protective layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. Each probe is made from a conductive, corrosion resistant material. This is particularly useful with water absorbent building materials, such as wood, where the surface may appear dry, but the body is impregnated with water. The preferred moisture probe is a U-shaped metal staple driven by a power stapler.

Claims

1. A method of detecting moisture in within and on a surface of an absorbent material, the method comprising:

providing a tape formed by a substrate of a dielectric, hydrophobic material, a layer of a mounting adhesive on a bottom surface of the substrate and a first and a second spaced apart elongate parallel conductors mounted on a top surface of the substrate and extending therealong;

attaching the tape by the adhesive on to a surface of the material so as to mount the two conductors on or adjacent the surface of the material;

providing at each of a plurality of longitudinally spaced locations along the adhesively attached tape a respective pair of plurality of pairs of conductive probes;

wherein each probe includes at least one rigid elongate conductive element of a corrosion resistant material;

forcing each probe longitudinally into the material at the respective location so as to penetrate through the surface of the material and to engage into the absorbent material;

as each probe of each pair is forced into the absorbent material, causing a first probe of each pair to penetrate the first conductor of the tape such that the first conductive probe is electrically connected to the first conductor by penetrating therethrough and causing a second probe of each pair to penetrate the second conductor of the tape such that the second conductive probe is electrically connected to the second conductor by penetrating therethrough;

applying a voltage across the two conductors; and

monitoring currents passing between the conductors so as to detect changes in electrical resistance between the conductors caused by moisture on the material and so as to detect changes in electrical resistance between the probes, caused by moisture content within the absorbent material.

2. A method according to claim 1 wherein the conductors of the tape are covered by a protective layer of non-hygroscopic, water pervious, dielectric material secured to the to the top surface of the substrate and extending over the conductors.

3. A method according to claim 1 wherein each of the conductors is a flat metal strip at least 6.5 mm wide.

4. A method according to claim 1 wherein the conductors are spaced apart by a distance of at least 13 mm.

5. A method according to claim 1 wherein the absorbent material is a moisture permeable element of a building construction.

6. A method of detecting moisture within and on a surface of an absorbent material, the method comprising:

providing a tape formed by a substrate of dielectric, hydrophobic material, a layer of a mounting adhesive on a bottom surface of the substrate and a first and a second spaced apart, elongate, parallel conductors mounted on a top surface of the substrate and extending therealong;

attaching the tape by the adhesive on to a surface of the material so as to mount the two conductors on or adjacent the surface of the material;

providing at each of a plurality of longitudinally spaced locations along the adhesively attached tape a respective pair of plurality of pairs of conductive probes;

wherein each probe includes at least one rigid elongate conductive element of a corrosion resistant material;

forcing each probe longitudinally into the material at the respective location so as to penetrate through the surface of the material and to engage into the absorbent material;

the probes of each pair being spaced apart such that current can flow through the material between the probes when moisture is present in the material;

as the first probe of each pair is forced into the absorbent material, causing the first probe to engage the first conductor of the tape such that the first conductive probe is electrically connected to the first conductor;

as the second probe of each pair is forced into the absorbent material, causing the second probe to engage the second conductor of the tape such that the second conductive probe is electrically connected to the second conductor;

applying a voltage across the first and second conductors; and

monitoring currents passing between the conductors so as to detect changes in electrical resistance between the conductors caused by moisture in the material and so as to detect changes in electrical resistance between the probes caused by moisture content within the absorbent material.

7. A method according to claim 6 wherein the first and second conductors of the tape are covered by a protective layer of non-hygroscopic, water pervious, dielectric material secured to the top surface of the substrate and extending over the conductors.

8. A method according to claim 6 wherein each of the first and second conductors is a flat metal strip at least 6.5 mm wide.

9. A method according to claim 6 wherein the first and second conductors are spaced apart by a distance of at least 13 mm.

10. A method according to claim 6 wherein each probe is a rigid elongate conductive element of corrosion resistant material which is forced into the material longitudinally of the element.

11. A method according to claim 6 wherein the absorbent material is a moisture permeable element of a building construction.

12. A method of detecting moisture on a surface of an absorbent material, the method comprising:

providing a tape formed by a substrate of dielectric, hydrophobic material, a layer of a mounting adhesive on a bottom surface of the substrate and a first and a second spaced apart, elongate, parallel conductors mounted on a top surface of the substrate and extending therealong;

wherein each of the first and second conductors is a flat metal strip laid flat on the top surface of the substrate;

wherein the first and second conductors of the tape are covered along the tape by a protective layer of non-hygroscopic, water pervious, dielectric material secured to the top surface of the substrate and extending over the conductors;

attaching the tape by the adhesive on to a surface of the material so as to mount the two conductors on or adjacent the surface of the material;

applying a voltage across the first and second conductors; and

monitoring currents passing between the conductors so as to detect changes in resistance between the conductors caused by moisture in the material.

13. A method according to claim 12 wherein the absorbent material is a moisture permeable element of a building construction.