A fast and precise chemiluminescence ozone detector for eddy flux and airborne application

Abstract

A commercially available dry chemiluminescence (CI) instrument for fast and precise measurement of ozone (O<sub>3</sub>) is specified. The sensitivity is ~9000 counts s<sup>−1</sup> per ppbv of ozone. Its precision is entirely determined by the number of photons reaching the detector (being a photomultiplier), i.e. is quantum-noise limited. The relative precision (ΔO<sub>3</sub>/O<sub>3</sub> in %) thus follows Poisson statistics and scales with the square root of the measurement frequency <i>f</i> and with the inverse O<sub>3</sub> mixing ratio: ΔO<sub>3</sub>/O<sub>3</sub> ∝ <i>f</i><sup>0.5</sup> · O<sub>3</sub><sup>−0.5</sup>. At typical O<sub>3</sub> mixing ratios between 10 and 100 ppbv, the precision is 0.3–1.0% at <i>f</i> = 10 Hz. The maximum measurement frequency is 50 Hz. The mechanical and electronic set-up as well as the instrument performance is described. Recommendations on the adequate inlet tube configuration (inlet tube length, sampling flow) and on the way of calibration at stationary ground-based platforms and onboard aircraft are given

Ozone concentrations, flux and potential effect on yield during wheat growth in the Northwest-Shandong Plain of China

“…Although its response time can reach 0.1 sec, the sensitivity is affected by the consumption of dye and environmental conditions, particularly the air humidity (Güsten et al, 1996;Muller et al, 2010). More information about the analyzer can be found in Zahn et al (2012). Air was drawn into the two analyzers through two PTFE (Teflon) tubes that were 3 m long with a 4 mm interior diameter.…”

Fundamental Review to Ozone Gas Sensing Using Optical Fibre Sensors

“…The authors have previously [13] highlighted quite a number of different methods for detecting ozone gas such as: cavity enhanced absorption spectroscopy (CEAS) [39,40], cavity ring down spectroscopy [41], chemiluminescence [42,43], electrochemical concentration cells [44], photo-acoustic sensors [45,46], photo reductive [47], solid state sensors [48] and UV absorption [49]. Authors of reference [50] …”

“…Whereas, ozone measurement with the method of chemiluminescence is not absolute, it has to be frequently calibrated. Chemiluminescence technique requires to be calibrated every 1 to 60 minutes [43]. Ozone absorbs light in the Hartley band (200-310 nm) [72], the Huggins band (310-375 nm), the Chappius band (375-603 nm), and the Wulf band (beyond 700 nm).…”

The effects of different calibration and frequency response correction methods on eddy covariance ozone flux measured with a dry chemiluminescence analyzer

“…To keep its high sensitivity, the dye covered disc has to be replaced every few days. Recently, Karlsruhe Institute of Technology and Enviscope GmbH (Germany) have cooperatively developed a new fast-response O 3 analyzer (Zahn et al, 2012, hereafter referred to as ENVI), which can be considered as an improved version of the analyzer originally developed by Güsten et al (1992). Moreover, very recently, Ermel et al (2013) have reported on a new preparation method for sensor discs suitable for ENVI measurements, which has greatly improved the stability and performance of sensor discs.…”

“…Only a few commercially available analyzers exist for fastresponse ozone measurements (Ray et al, 1986;Güsten et al, 1992;Zahn et al, 2012). All of them are so-called "closed-path" instruments, and most of them are custom-built and have been used in the field for short time periods (Yushkov et al, 1999;Kurpius et al, 2002;Coyle et al, 2009;Muller et al, 2009Muller et al, , 2010.…”