Temperature measuring system and temperature measuring method

Patent metadata

Field	Value
Publication number	US-2016238461-A1
Application number	US-201614992343-A
Country	US
Kind code	A1
Filing date	Jan 11, 2016
Priority date	Feb 12, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

A temperature measuring system includes a laser light source to emit optical pulses, an optical fiber, arranged to pass through a plurality of measuring points, and input with the optical pulses, and a measuring device to detect back-scattering light output from the optical fiber and measure a temperature at the plurality of measuring points, to acquire measured temperature data. The measuring device computes corrected temperature data by varying a degree of smoothing the measured temperature data in a distance direction of the optical fiber, according to a correlation between the measured temperature data and a transfer function peculiar to the temperature measuring system.

First claim

What is claimed is:

1 . A temperature measuring system comprising:
a laser light source configured to emit optical pulses; an optical fiber, arranged to pass through a plurality of measuring points, and input with the optical pulses; and a measuring device configured to detect back-scattering light output from the optical fiber and measure a temperature at the plurality of measuring points, to acquire measured temperature data, wherein the measuring device computes corrected temperature data by varying a degree of smoothing the measured temperature data in a distance direction of the optical fiber, according to a correlation between the measured temperature data and a transfer function peculiar to the temperature measuring system.

2 . The temperature measuring system as claimed in claim 1 , wherein the correlation is a correlation between a difference between the measured temperature data and a moving average of the measured temperature data, and the transfer function.

3 . The temperature measuring system as claimed in claim 2 , wherein the measuring device performs a first weighting on the measured temperature data when a condition that a correlation coefficient representing the correlation is greater than a threshold value is satisfied, and performs a second weighting, different from the first weighting, on the measured temperature data when the condition is not satisfied, to vary the degree of smoothness of the measured temperature data in the distance direction of the optical fiber.

4 . The temperature measuring system as claimed in claim 3 , wherein the first weighting computes the corrected temperature data by performing a weighting by 1 on the measured temperature data.

5 . The temperature measuring system as claimed in claim 2 , wherein the measuring device performs a first weighting on the measured temperature data when a condition that an absolute value of a product of the temperature at each of the plurality of measuring points and a correlation coefficient representing the correlation is greater than or equal to a threshold value is satisfied, and performs a second weighting, different from the first weighting, on the measured temperature data when the condition is not satisfied, to vary the degree of smoothness of the measured temperature data in the distance direction of the optical fiber.

6 . The temperature measuring system as claimed in claim 5 , wherein the first weighting computes the corrected temperature data by performing a weighting by 1 on the measured temperature data.

7 . The temperature measuring system as claimed in claim 1 , wherein the laser light source is one of a solid state laser and a semiconductor laser.

8 . A temperature measuring method comprising:
inputting optical pulses emitted from a laser light source of a temperature measuring system to an optical fiber that is arranged to pass through a plurality of measuring points; detecting back-scattering light output from the optical fiber and measuring a temperature at the plurality of measuring points by a measuring device to acquire measured temperature data; and computing, by the measuring device, corrected temperature data by varying a degree of smoothing the measured temperature data in a distance direction of the optical fiber, according to a correlation between the measured temperature data and a transfer function peculiar to the temperature measuring system.

9 . The temperature measuring method as claimed in claim 8 , wherein the correlation is a correlation between a difference between the measured temperature data and a moving average of the measured temperature data, and the transfer function.

10 . The temperature measuring method as claimed in claim 9 , wherein the computing performs a first weighting on the measured temperature data when a condition that a correlation coefficient representing the correlation is greater than a threshold value is satisfied, and performs a second weighting, different from the first weighting, on the measured temperature data when the condition is not satisfied, to vary the degree of smoothness of the measured temperature data in the distance direction of the optical fiber.

11 . The temperature measuring method as claimed in claim 10 , wherein the first weighting computes the corrected temperature data by performing a weighting by 1 on the measured temperature data.

12 . The temperature measuring method as claimed in claim 9 , wherein the computing performs a first weighting on the measured temperature data when a condition that an absolute value of a product of the temperature at each of the plurality of measuring points and a correlation coefficient representing the correlation is greater than or equal to a threshold value is satisfied, and performs a second weighting, different from the first weighting, on the measured temperature data when the condition is not satisfied, to vary the degree of smoothness of the measured temperature data in the distance direction of the optical fiber.

13 . The temperature measuring method as claimed in claim 12 , wherein the first weighting computes the corrected temperature data by performing a weighting by 1 on the measured temperature data.

14 . The temperature measuring method as claimed in claim 8 , wherein the laser light source is one of a solid state laser and a semiconductor laser.

15 . A non-transitory computer-readable recording medium having stored therein a program for causing a computer of a temperature measuring system to execute a temperature measuring process comprising:
detecting back-scattering light output from an optical fiber that is arranged to pass through a plurality of measuring points and is configured to receive optical pulses, and measuring a temperature at the plurality of measuring points to acquire measured temperature data; and computing corrected temperature data by varying a degree of smoothing the measured temperature data in a distance direction of the optical fiber, according to a correlation between the measured temperature data and a transfer function peculiar to the temperature measuring system.

16 . The non-transitory computer-readable recording medium as claimed in claim 15 , wherein the correlation is a correlation between a difference between the measured temperature data and a moving average of the measured temperature data, and the transfer function.

17 . The non-transitory computer-readable recording medium as claimed in claim 16 , wherein the computing performs a first weighting on the measured temperature data when a condition that a correlation coefficient representing the correlation is greater than a threshold value is satisfied, and performs a second weighting, different from the first weighting, on the measured temperature data when the condition is not satisfied, to vary the degree of smoothness of the measured temperature data in the distance direction of the optical fiber.

18 . The non-transitory computer-readable recording medium as claimed in claim 17 , wherein the first weighting computes the corrected temperature data by performing a weighting by 1 on the measured temperature data.

19 . The non-transitory computer-readable recording medium as claimed in claim 16 , wherein the computing performs a first weighting on the measured temperature data when a condition that an absolute value of a product of the temperature at each of the plurality of measuring points and a correlation coefficient representing the correlation is greater than or equal to a threshold value is satisfied, and perfor

Assignees

• Fujitsu Ltd

Inventors

• Arioka Takahiro
• Uno Kazushi
• Kasajima Takeo
• Takei Fumio
• Fukuda Hiroyuki

Classifications

• G01K11/32 Primary

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title

• G01K2011/322

  Physics · mapped topic

• G01K2011/324

  Physics · mapped topic