A
continuous monitoring method for
methane emission of a mine return
airway is characterized in that a
methane concentration detection method is realized by combining DAS with a WMS technology, the WMS technology has good
linearity when the concentration is low, when the
absorbance is close to an
absorbance threshold value A0, a nonlinear effect begins to appear, and the
gas concentration cannot be accurately inverted, at the moment, the DAS technology shows good
linearity, and the WMS technology shows high
linearity when the
gas concentration cannot be accurately inverted. And the detection range can be greatly improved. Therefore, the concentration detection of the
methane gas in the whole range can be realized by combining the DAS with the WMS technology, and by setting a proper
absorbance threshold value A0, when the absorbance of the detected gas to be detected is lower than the set threshold value, the WMS technology is adopted to ensure the measurement accuracy of the detection
system under the low-concentration condition; when the absorbance of the detected to-be-detected gas is higher than a set threshold value, the DAS technology is adopted for detection, so that the nonlinear problem caused by adopting the WMS technology is avoided. The method has high sensitivity to the detected change of the
volume concentration of the methane, and the change of the
volume concentration of the methane can be detected in time.