Datalogger prototyping for NH3 ground-level concentrations measurements and comparison with NH3-IASI generated datamaps

Abstract

Ammonia (NH3) is a highly dangerous gas due to its
toxicity and irritating properties which cause severe eye burns
and respiratory problems (throat and lung damages) when
inhaled in high concentrations. It is a colorless gas, with a strong
suffocating odor. It is also a flammable gas (potentially forming
explosive mixtures with air when heated). Ammonia readily
dissolves in water to form ammonium hydroxide solution
(NH4OH), a highly corrosive agent that can damage metallic
structures such as bridges, boats, water tanks, etc… It can also
react with other atmospheric pollutants, primarily SO2 and NOx,
generating fine particulate matter which can pass through the
lungs into the bloodstream, posing great health risks. On the
other hand, it is also considered as an industrial useful hydrogen
carrier of energy, and an additive for coal-fired power plants,
and is slowly repurposed from its natural role as a fertilizer in
the agricultural industry to a “green and clean” fuel source. In
this article, we describe in detail the use of an electrochemical
sensor driven by a microcontroller. The principle of the
measurement system is a chemical oxidation of catalyst metals,
where conductivity varies with the target gas concentration.
Mathematical calculations are also provided to convert the 10-bit
numerical counts to meaningful NH3 concentrations in ppm,
taking into account the temperature dependency correction. As a
final stage, 4 months of data acquisition has been carried out in
the petrochemical industrial city of Arzew.