Development of airborne instrument for CO measurement

研制了一种基于真空紫外共振荧光技术的对流层CO快速、高精度测量仪。利用直流放电CO共振灯结合光学滤波器获得150 nm左右的CO 4+正带发射激发辐射<th>。滤光片由真空紫外单色器和石英晶体窗口（&lt;147 nm截止）组成。石英晶体窗口确保了对135.7 nm以下波长的清晰识别，这会产生来自水蒸气的正干扰。实验室测试表明，光学系统在100 ppbv的CO浓度下实现了1.1ppbv的精度，积分时间为1秒，流量系统提供了约2秒的响应时间（1/e时间常数）。1999年8月至9月，在澳大利亚上空进行了生物量燃烧和闪电试验阶段B（BIBLE-B）的飞机测量活动。在这次活动中获得的飞行数据被用来证明该仪器的高精度和快速响应。在BIBLE-B期间进行了VUV CO测量和气相色谱CO测量的相互比较。总的来说，这两个独立的测量显示出良好的一致性，在实验的不确定性。

An airborne instrument for fast-response, high-precision measurement of tropospheric carbon monoxide (CO) was developed using a vacuum ultraviolet (VUV) resonance fluorescence technique. The excitation radiation is obtained by a DC discharge CO resonance lamp combined with an optical filter for the CO 4^<th> positive band emission around 150nm. The optical filter consists of a VUV monochromator and a crystalline quartz window (<147nm cutoff). The crystalline quartz window ensures sharp discrimination against wavelengths below 135.7nm, which yields a positive interference from water vapor. Laboratory tests showed that the optical system achieves a precision of 1.1 parts per billion by volume(ppbv) at a CO concentration of 100ppbv for a 1-seconds intergration period, and flow system provides a response time(1/e time constant) of about 2 seconds. The aircraft measurement campaign Biomass Burning and Lightning Experiment-phase B (BIBLE-B ) took place between August and September 1999 over Australia. The flight data obtained during this campaign are used to demonstrate the high precision and fast response of the instrument. An intercomarison of the VUV CO measurement and a gas chromatographic CO measurement was conducted during BIBLE-B. Overall, these two independent measurements showed good agreement, within the experimental uncertainties.