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

Ammonia (NH3) gas is dangerous as it is highly toxic and irritating and so, causes severe burning of the eyes 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 (and may form an explosive mixture with air, when heated), and can dissolve in water to form ammonium hydroxide solution, a highly corrosive agent for any metallic based structures like 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 in blood. In the other hand, it is considered as an industrial useful hydrogen carrier of energy, and an additive to coal-fired power plants, and is slowly shifting from its natural use as fertilizer for 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.