Optical fiber temperature sensing device

An optical fiber temperature sensing device, comprising:

• a sensor body;
• a light source housed in the sensor body;
• a temperature measuring optical fiber disposed outside the sensor body and extended to a temperature measurement site, wherein, when a light is emitted from the light source into the temperature measuring optical fiber, Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the temperature measuring optical fiber are detected to determine a temperature at the temperature measurement site;
• a reference temperature optical fiber disposed inside the sensor body;
• and
• a controller that is operable to control an output of the light source by monitoring Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the reference temperature optical fiber,
• wherein:
• the controller is operable to previously determine reference calculated values from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the reference temperature optical fiber at plural temperatures, to store the reference calculated values into a memory device, to determine a first calculated value from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the reference temperature optical fiber at an arbitrary temperature, to output a second calculated value at the arbitrary temperature from the reference calculated values, and to control a bias electrical current applied to the light source to make the first calculated value equal to the second calculated value.

An optical fiber temperature sensing device, comprising:

• a sensor body;
• a light source housed in the sensor body;
• an optical fiber disposed from an inside of the sensor body to a temperature measurement site, to measure a temperature at the temperature measurement site by detecting Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the optical fiber when a light is emitted from the light source into the optical fiber;
• and
• a controller to control an output of the light source by monitoring Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the optical fiber,
• wherein:
• the controller is operable to previously determine reference calculated values from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in a reference temperature optical fiber at least at two arbitrary temperatures, to determine an approximation formula representing a relationship between the reference calculated values and the two arbitrary temperatures, to store the approximation formula in a memory device, to determine a first calculated value from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the reference temperature optical fiber at an other temperature, to determine a second calculated value at the other temperature by using the approximation formula, and to control a bias electrical current applied to the light source to make the first calculated value equal to the second calculated value.

Optical fiber temperature sensing, comprising:

• a sensor body;
• a light source housed in the sensor body;
• an optical fiber disposed from an inside of the sensor body to a temperature measurement site, to measure a temperature at the temperature measurement site by detecting Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the optical fiber when a light is emitted from the light source into the optical fiber;
• and
• a controller to control an output of the light source by monitoring Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the optical fiber,
• wherein:
• the controller is operable to previously determine reference calculated values from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in a reference temperature optical fiber at plural temperatures, to store the reference calculated values into a memory device, to determine a first calculated value from Stokes light intensity and anti-Stokes light intensity of backscattered light generated in the reference temperature optical fiber at an arbitrary temperature, to output a second calculated value at the arbitrary temperature from the reference calculated values, and to control a bias electrical current applied to the light source to make the first calculated value equal to the second calculated value.