光子学报 ›› 2020, Vol. 49 ›› Issue (10): 1012002-1012002.doi: 10.3788/gzxb20204910.1012002

• 仪器,测量,度量学 • 上一篇    下一篇

宽温紧凑型全量程激光甲烷传感探头设计

庞涛1,2(), 孙鹏帅1, 张志荣1,2,3(), 吴边1, 夏滑1,2, 徐启铭4   

  1. 1.中国科学院安徽光学精密机械研究所 光子器件与材料安徽省重点实验室,合肥 230031
    2.中国科学院安徽光学精密机械研究所 中国科学院环境光学与技术重点实验室,合肥 230031
    3.先进激光技术安徽省实验室,合肥 230037
    4.台湾云林科技大学 环境安全工程系,台湾 云林 64002
  • 收稿日期:2020-05-12 接受日期:2020-07-20 出版日期:2020-10-25 发布日期:2020-10-13
  • 通讯作者: 张志荣 E-mail:bumianren123@163.com;zhangzr@aiofm.ac.cn
  • 作者简介:庞涛(1981-),男,助理研究员,博士,主要研究方向为高灵敏吸收光谱仪表开发. Email: bumianren123@163.com
  • 基金资助:
    国家重点研发计划(2017YFC0805004);国家自然科学基金(11874364);中国科学院对外合作重点项目支持(GJHZ1726);安徽省重点研究与开发计划项目(201904c03020005);安徽省科技重大专项(18030901054)

Design of Compact Full-range Laser Methane Sensor with Wide Temperature Range

Tao PANG1,2(), Peng-shuai SUN1, Zhi-rong ZHANG1,2,3(), Bian WU1, Hua XIA1,2, Chi-min SHU4   

  1. 1.Anhui Provincial Key Laboratory of Photonic Devices and Materials,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China
    2.Key Lab of Environmental Optics & Technology,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China
    3.Advanced Laser Technology Laboratory of Anhui Province,Heifei 230037,China
    4.Department of Safety Health and Environmental Engineering,Yunlin University of Science and Technology,Yunlin,Taiwan 64002,China
  • Received:2020-05-12 Accepted:2020-07-20 Online:2020-10-25 Published:2020-10-13
  • Contact: Zhi-rong ZHANG E-mail:bumianren123@163.com;zhangzr@aiofm.ac.cn
  • Supported by:
    National Key Research and Development Program of China(2017YFC0805004);National Natural Science Foundation of China(11874364);External Cooperation Program of Chinese Academy of Sciences(GJHZ1726);Key Research and Development Projects of Anhui Province(201904c03020005);Major Science and Technology Projects of Anhui Province(18030901054)

摘要:

针对测量动态范围大、室外环境温度变化剧烈等因素,设计了宽温度范围(-40~60℃)紧凑型全量程激光甲烷探头.为减小传感器体积,电路采用层叠结构设计,通过单片机STM32F405实现激光器温度控制、波长扫描调制、数字锁相放大及浓度信息实时反演.电路系统和测量气室封装在仅Φ35 mm×60 mm的不锈钢外壳内,中间有窗片实现物理隔离,确保本质安全.低浓度时使用波长调制技术,保证探头测量精度和测量下限;高浓度时,使用直接吸收光谱技术,保证量程和线性度.在25℃标准大气压下,低浓度(<2%)测量误差小于±5.00×10-4,检出限为2.24×10-4,在允许基线校准或者背景扣除的条件下,测量下限可以提高到6.026×10-5;高浓度(2~100%)测量误差小于真值的±5%.在-40~60℃环境温度下,分别使用1.2%和20%标准气体进行温度性能测试,最大相对测量误差为-3.3%和-3.15%,完全满足国家相关标准要求,可广泛应用于城市综合管廊、天然气管道及站场泄露监测、煤矿安全预警等场合.

关键词: 可调谐半导体激光吸收光谱, 二次谐波, 直接吸收, 温度补偿, 全量程激光甲烷传感器

Abstract:

Account for big temperature difference and large dynamic range in the application environment, a compact full-range laser methane probe with a wide temperature range of -40~60℃ is designed. To reduce the volume of probe, cascade structure design is adopted for circuit. Single-chip microcomputer STM32F405 is used to realize laser temperature control, wavelength scanning modulation, digital phase-locked amplification and real-time inversion of concentration information. The circuit system and gas chamber are encapsulated in a stainless steel case of only Φ35 mm×60 mm, with windows in the middle to achieve physical isolation, ensuring intrinsic safety. At low concentration, wavelength modulation technology is used to ensure the measurement accuracy and measurement limit. Direct absorption spectroscopy technology is used to ensure the range and linearity, when the environmental concentration is high. At 25℃, standard atmospheric pressure, the measurement error of low concentration (<2%) is less than ±5.00×10-4, and the detection limit is 2.24×10-4. Under the condition of allowing baseline calibration or background subtraction, the limit could reach 6.026×10-5. The measurement error of high concentration (2~100%) is less than ±5% of the true value. At the ambient temperature of -40~60℃, 1.2% and 20% standard gases are used for the temperature performance test, respectively. The maximum relative measurement error are -3.3% and -3.15%, which fully met the requirement of national standards. It can be widely used in the urban comprehensive pipe corridor, gas station leakage monitoring, coal mine safety warning and other occasions.

Key words: Tunable semiconductor laser absorption spectrum, Second harmonic, Direct absorption, Temperature compensation, Full-range laser methane sensor

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