주파수 변조 흡수 분광법 기반 극미량 누설 가스 원격 검출 기술 (Remote Detection Technique of Trace Leak Gas based on Frequency Modulation Absorption Spectroscopy)

서지정보

· 발행기관 : 한국정밀공학회
· 수록지 정보 : 한국정밀공학회지 / 41권 / 10호 / 741 ~ 746페이지
· 저자명 : 박정재, 이재용, 우제흔, 진종한

초록

The LIDAR principle is used in a variety of fields, including large-scale pipeline facility management, industrial disastersafety control, and atmospheric environmental monitoring, to employ the remote gas detection technique. In this study, wedesigned and implemented a remote detection method for N2O gas leaks using absorption spectroscopy based onfrequency modulation of a Mid-IR quantum cascade laser (QCL) with a wavelength of 4.5 μm. We direct the frequencymodulatedbeam, locked to a single absorption line of N2O, to a leak hole on a target surface within a range ofapproximately 50 m. For area scanning around the leak point, we use a galvano scanner to deflect the probe beam. Theback-scattered beam from the diffuse target surface is then collected by a Cassegrain telescope with a diameter of 300mm and detected by an InSb photo-detector with high photon sensitivity. To process the detected signal, we utilizefundamental and second harmonic detection with a lock-in amplifier, resulting in a relative gas concentration expressed asthe second harmonic signal normalized by the fundamental signal. Our test results demonstrate that this proposed methodcan detect gas leaks as small as 0.005 sccm at a distance of 50 m.

영어초록

The LIDAR principle is used in a variety of fields, including large-scale pipeline facility management, industrial disastersafety control, and atmospheric environmental monitoring, to employ the remote gas detection technique. In this study, wedesigned and implemented a remote detection method for N2O gas leaks using absorption spectroscopy based onfrequency modulation of a Mid-IR quantum cascade laser (QCL) with a wavelength of 4.5 μm. We direct the frequencymodulatedbeam, locked to a single absorption line of N2O, to a leak hole on a target surface within a range ofapproximately 50 m. For area scanning around the leak point, we use a galvano scanner to deflect the probe beam. Theback-scattered beam from the diffuse target surface is then collected by a Cassegrain telescope with a diameter of 300mm and detected by an InSb photo-detector with high photon sensitivity. To process the detected signal, we utilizefundamental and second harmonic detection with a lock-in amplifier, resulting in a relative gas concentration expressed asthe second harmonic signal normalized by the fundamental signal. Our test results demonstrate that this proposed methodcan detect gas leaks as small as 0.005 sccm at a distance of 50 m.

참고자료

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