OPTICAL FIBER TEMPERATURE DISTRIBUTION MEASURING DEVICE

• US 20160003687A1
• Filed: 06/16/2015
• Published: 01/07/2016
• Est. Priority Date: 07/07/2014
• Status: Active Grant

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: TAKEUCHI, Nobuaki
• Granted Patent: US 10,018,517 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01K 11/32 using changes in transmittance, scattering or luminescence in optical fibres
• CPC Class Codes: G01K 11/322 using Brillouin scattering
• CPC Class Codes: G01K 11/324 using Raman scattering

Abstract

An optical fiber temperature distribution measuring device includes: an optical fiber as a sensor; a calculation control unit for measuring a temperature distribution along the optical fiber based on an intensity ratio between Stokes light and anti-Stokes light of backward Raman scattered light from the optical fiber; and a temperature correction unit for correcting the temperature distribution by using temperature dependence of a loss difference between the Stokes light and the anti-Stokes light.

Claims

1. An optical fiber temperature distribution measuring device comprising:

an optical fiber as a sensor;

a calculation control unit for measuring a temperature distribution along the optical fiber based on an intensity ratio between Stokes light and anti-Stokes light of backward Raman scattered light from the optical fiber; and

a temperature correction unit for correcting the temperature distribution by using temperature dependence of a loss difference between the Stokes light and the anti-Stokes light.

2. The optical fiber temperature distribution measuring device according to claim 1, wherein

the temperature correction unit includes an optical fiber loss correction temperature storing unit for storing a temperature of the optical fiber at a point in time when a loss correction value of the optical fiber is obtained.

3. The optical fiber temperature distribution measuring device according to claim 1, wherein

the temperature correction unit includes an optical fiber loss temperature characteristic storing unit for storing a temperature characteristic of a loss value of the optical fiber.

4. The optical fiber temperature distribution measuring device according to claim 2, wherein

the temperature correction unit includes an optical fiber loss temperature characteristic storing unit for storing a temperature characteristic of a loss value of the optical fiber.

5. The optical fiber temperature distribution measuring device according to claim 4, wherein

the temperature correction unit further includes:

an optical fiber loss correction value storing unit for storing a loss correction value of the optical fiber; and

a temperature correction calculation unit for correcting the temperature distribution by using the loss correction value of the optical fiber.

6. The optical fiber temperature distribution measuring device according to claim 5, wherein

the temperature correction unit further includes a loss correction value calculation unit for correcting the temperature distribution by using the temperature dependence of the loss difference between the Stokes light and the anti-Stokes light based on the temperature of the optical fiber at the point in time when the loss correction value of the optical fiber is obtained, the temperature characteristic of the loss value of the optical fiber, and the temperature distribution corrected by the temperature correction calculation unit.

7. The optical fiber temperature distribution measuring device according to claim 1, further comprising

an optical branching device for receiving the backward Raman scattered light and separating the backward Raman scattered light into the Stokes light and the anti-Stokes light.