A new method of distributed optical fiber temperature measurement system with the temperature effect of Raman scattering and optical time domain reflection（ OTDR） for the detection of leakage from the new type of landfill without clay are proposed in this paper. Because the specific heat capacity of wet GCL is greater than that of the dry GCL after heating of the optical fiber of test,the temperature of the leakage position was apparently lower than that of the non-leakage area. The Raman scattering light was used to obtain temperature information,and the OTDR was used to locate the leakage accurately. In this article,a mathematical model for the detection of landfill leakage was established,and the feasibility of this method was shown by theoretical deduction and experimental study. The experimental results show that the simulation of the impermeable membrane was highly consistent with the measured results,with a maximum positioning reference error of 0. 11%. The distributed optical fiber temperature measurement system monitored in real time,the temperature changes of the GCL layer accurately and met the special requirements for landfills of long distance,large range,and high corrosion.
Techniques and Equipment for Environmental Pollution Control
optical time domain reflection