Taketani Fumikazu, Kawai Megumi, Takahashi Kenshi, Matsumi Yutaka
Solar-Terrestrial Environment Laboratory, Graduate School of Science, Nagoya University, Honohara, Toyokawa, Aichi, Japan.
Appl Opt. 2007 Feb 20;46(6):907-15. doi: 10.1364/ao.46.000907.
We report on the development of a highly sensitive detection system for measuring atmospheric NO(2) by means of a laser-induced fluorescence (LIF) technique at 473 nm using a diode-pumped Nd:YAG laser. A GaN-based laser diode emitting at 410 nm is also used as an alternative fluorescence-excitation source. For laboratory calibrations, standard NO(2) gas is diluted with synthetic air and is introduced into a fluorescence-detection cell. The NO(2) LIF signal is detected by a photomultiplier tube and processed by a photon-counting method. The minimum detectable limits of the NO(2) instrument developed have been estimated to be 0.14 ppbv and 0.39 ppbv (parts per billion, 10(-9), by volume) in 60 s integration time (signal-to-noise ratio of 2) for 473 and 410 nm excitation systems, respectively. Practical performance of the instrument has been demonstrated by the 24 hour continuous measurements of ambient NO(2) in a suburban area.
我们报告了一种高灵敏度检测系统的研发情况，该系统利用激光诱导荧光（LIF）技术，借助二极管泵浦的Nd:YAG激光器，在473纳米波长下测量大气中的二氧化氮（NO₂）。一种发射波长为410纳米的基于氮化镓（GaN）的激光二极管也被用作替代的荧光激发源。在实验室校准中，标准NO₂气体用合成空气稀释后被引入荧光检测池。NO₂的LIF信号由光电倍增管检测，并通过光子计数法进行处理。对于473纳米和410纳米激发系统，在60秒积分时间（信噪比为2）内，所研发的NO₂仪器的最低检测限分别估计为0.14 ppbv和0.39 ppbv（十亿分比，体积比为10⁻⁹）。该仪器的实际性能已通过在郊区对环境NO₂进行24小时连续测量得到了验证。
