First, the specifications for both ozone and VOC analyser were described and detailed in agreement with the Topic Manager.
VOC ANALYSER
Regarding the VOC analyser, a laboratory prototype was developed from an existing instrument able to quantify Benzene and its derivative and already developed by CNRS in collaboration with an industrial partner before the beginning of MACAO Project. To enlarge the number of detectable species, a second “universal” detector was added and placed in series with the PhotoIonisation Detector (PID). To improve its sensitivity, a preconcentrator was successfully developed to concentrate the airborne VOC samples. In fact, 6 versions of preconcentrator were implemented successively until satisfactory results were obtained. The final preconcentrator finalized was tested under controlled conditions, demonstrating that it meets the requirements established in the objectives of this project in terms of sensitivity, energy consumption, analysis duration, repeatability, and reproducibility. The benzene Limit Of Quantification (LOQ) achieved (0.191 ppb which is equivalent to about 5 pg) with an air sample of only 20 mL was found to be lower than the threshold value established in the recent French legislation concerning indoor air quality (0.6 ppb).
OZONE ANALYSER
Concerning the ozone analyser, the first technological solutions considered were abandoned either because of the lack of sensitivity obtained or because of the need for dangerous gases which was incompatible with use in an airplane. A laboratory prototype was first developed based on differential measurements obtained with sensors. Indeed, nitric dioxide (NO2) being an interferent for the ozone sensor, its concentration must be measured to correct the ozone measurement. Finally, an ozone analyser demonstrator was then developed at ICPEES to monitor airborne ozone concentrations in real-time. It included the mechanical design using Computer Aids Design, the development and manufacturing of electronic boards, the realization of a custom case using 3D printing. An embedded software for this instrument was also developed through the Arduino development environment.
EXPLOITATION AND DISSEMINATION
Numbers of published papers and oral communications during the whole duration of the project:
- 1 PhD Thesis
- 7 papers in international journals
- 12 oral communications in international conferences or workshops
- 1 oral communication in a national workshop
A patent related to the preconcentrator was submitted by ICPEES (CNRS, partner 1) in March, 2020.
