Table 8 Sensing results, advantages and characteristics of different types of sensing fiber schemes
From: Physics and applications of Raman distributed optical fiber sensing
Schemes | Sensing distance | Spatial resolution | Temperature accuracy | Advantages | Sensing characteristics |
|---|---|---|---|---|---|
Multi-mode fiber sensing | 25 km | 2.58 m | 0.7 °C | Larger backscattering coefficients, and its SNR is higher at an effective sensing distance. It is suitable for the fields which demand a high temperature measurement accuracy, such as petrochemical temperature monitoring, pipeline leakage fields. | (1) The fiber dispersion and attenuation coefficient deteriorate the effective sensing distance. (2) It is easy to stimulate the Raman effect. |
Single-mode fiber sensing | 25 km | 1 m | 6.9 °C | The fiber attenuation and fiber dispersion are small. It is suitable for long-distance linear engineering monitoring. | The Raman gain within the effective sensing distance is small. Temperature accuracy is small compared to other sensing schemes. |
Few-mode fiber sensing | 25 km | 1.13 m | 1.0 °C | The system combines the advantages of the multi-mode fiber scheme (high Raman gain) and the single-mode fiber sensing scheme (small fiber dispersion). | Few-mode fiber is more expensive compared to other sensing fibers. |