Mobile gas sensing system for detection of combustion pollutants – suitable for drone based measurements

A low cost and compact sensor system for mobile measurements of combustion gases is described. The sensor utilizes optical absorptions in the UV-Vis range using LED-based spectroscopy. Combustion processes are currently one major cornerstone in the way we are using primary energy sources in our modern life. Harmful gases such as nitrogen oxides (NOx) and sulfur dioxide (SO2) as well as particles are emitted thereby in significant amounts if the processes, engines, catalysts and filters are not working properly. It is important to enable an easy to use and low cost monitoring of these harmful emissions: Applications are spot check emission control in transport, in industry, in harbor areas or mobile functionality control in operation of combustion devices and industrial gas filters. A cost effective mobile sensor is realized for the measurement of NO2 and SO2 in wide dynamic range from 0.1 ppm to a few 1000 ppm with high temporal dynamic (100 msec). Further an opacimeter measurement and a stray light sensor for particle detection are included. In addition temperature, humidity and pressure are measured. The presented sensor design is optimized for mobile airborne gas measurements. Its construction is adapted to a license free commercial 1400 g video drone. The sensor is simply clicked under the drone, while the drone functionalities (video, distance sensors etc.) are not influenced by the gas sensor. The sensors weight is about 300 g including its battery. The measurement data are recorded on SD-card and are send for online visualization via Bluetooth e.g. to a smartphone. The light weight, compact, robust and low power consuming battery powered sensor design can also be used in hand held devices. In addition the sensor can easily be modified for other gases such as for ozone (O3) detection.