How fiber scattering becomes a temperature profile
Inside the sensing fiber, the laser pulse generates Raman backscattering. The Stokes signal is relatively stable and used as a reference, while the Anti-Stokes signal increases as temperature rises. HZ-DTS calculates temperature from the Anti-Stokes / Stokes ratio and uses OTDR return time to locate the event along the fiber.
Temperature changes the Anti-Stokes signal.
When the local fiber temperature rises, molecular vibration increases. This strengthens the Anti-Stokes Raman backscatter, while the Stokes signal remains comparatively stable. The ratio between the two signals is converted into temperature.
DTS records temperature data point-by-point along the sensing fiber.
Laser Pulse
The DTS analyzer sends short optical pulses into the sensing fiber.
Raman Scattering
Stokes and Anti-Stokes Raman signals return from each point of the fiber.
Temperature Ratio
A stronger Anti-Stokes signal indicates higher local fiber temperature.
OTDR Mapping
Return time maps the temperature result to an accurate distance location.
