Performance comparison between Raman and Brillouin intensity based sub metre spatial resolution temperature compensated distribued strain sensor

摘要

With the capability of Brillouin Optical Correlation Domain Analysis (BOCDA) technique to probe measurands with millimeter order spatial resolution [1], the idea of combining intensity measurements with BOCDA for high spatial resolution temperature compensated distributed strain sensing has been explored and successfully demonstrated [2, 3]. This paper discusses the advantages of achieving this temperature compensation using Raman [2] or Brillouin intensity measurements [3]. Fig. 1 shows a summary of temperature compensation strain measurements made using Raman/Brillouin intensity in combination with Brillouin frequency based BOCDA. The 131m long sensing fibre comprised a 42m unheated-unstrained section, 14.5m of unstrained section maintained at 52°C, 33m unheated-unstrained section, 3.5m unheated section subject to 1044 µ.epsilon over a fibre strain rig and 38m unheated-unstrained section of standard single mode telecommunications fibre.