Optical fiber moisture sensor

• US 5,243,670 A
• Filed: 07/31/1992
• Issued: 09/07/1993
• Est. Priority Date: 08/02/1991
• Status: Expired due to Fees

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Bonicel, Jean-Pierre
• Primary Examiner(s): FONT, FRANK G
• Application Number:
  US07/922,476
• Time in Patent Office: 403 Days
• Field of Search: 385/12, 385/13, 250/227.14, 250/227.15
• US Class Current: 385/13
• CPC Class Codes: G01D 5/35377 Means for amplifying or modifying the measured quantity
• CPC Class Codes: G01N 19/10 Measuring moisture content, e.g. by measuring change in length of hygroscopic filament; Hygrometers

Abstract

An optical fiber moisture sensor comprising a mechanical system having a stationary jaw and a moving jaw between which said fiber is mounted, the sensor also including an element made of moisture-sensitive material coupled to said moving jaw to allow it to be urged towards said stationary jaw in the presence of moisture, thereby applying compression to said optical fiber, wherein said element is made of a material that looses mechanical strength with increasing moisture and that is mounted to oppose the action of resilient means urging said moving jaw towards said stationary jaw.

Claims

1. An optical fiber moisture sensor comprising a mechanical system having a stationary jaw and a moving jaw between which an optical fiber is mounted, the sensor also including an element made of moisture-sensitive material coupled to said moving jaw to allow said moving jaw to be urged towards said stationary jaw in the presence of moisture, thereby applying compression to said optical fiber, wherein said element is made of a material that looses mechanical strength with increasing moisture and that is mounted to oppose the action of resilient means urging said moving jaw towards said stationary jaw.

2. A sensor according to claim 1, wherein said element made of moisture-sensitive material is mounted as a spacer between said jaws.

3. A sensor according to claim 1, wherein at least one of said jaws has a shoulder facing the other jaw.

4. A sensor according to claim 3, wherein the edge of said shoulder is serrated, or corrugated, and/or convex.

5. A sensor according to claim 1, wherein said element of moisture-sensitive material is made of a material defined by materials based on cellulose, polyacrylamide, saccharose, and carbon hydrate.

6. A sensor according to claim 1, wherein said optical fiber is independent of an optical link monitored by means of said sensor.

7. A sensor according to claim 1, wherein said optical fiber belongs an optical link monitored by means of said sensor.

8. A sensor according to claim 6, wherein said optical fiber is monomode.

9. A sensor according to claim 6, wherein said optical fiber is multimode.

10. A sensor according to claim 7, wherein said optical fiber is monomode.

11. A sensor according to claim 7, wherein said optical fiber is multimode.