%0 Journal Article
%T Calibration of CO and CO<sub>2</sub> Monitors Used in Periodic Inspection of Vehicles at Fixed Stations for Environmental Control
%A Adel Bassuoni Shehata
%A Abdulrahman Rashed Al Askar
%A Najjy Hamad Al Yami
%A Abdullah Suleiman Al Owaysi
%A Sultan K. Alharbi
%J Green and Sustainable Chemistry
%P 29-41
%@ 2160-696X
%D 2024
%I Scientific Research Publishing
%R 10.4236/gsc.2024.142003
%X Global efforts for environmental cleanliness through the control of gaseous emissions from vehicles are gaining momentum and attracting increasing attention. Calibration plays a crucial role in these efforts by ensuring the quantitative assessment of emissions for informed decisions on environmental treatments. This paper describes a method for the calibration of CO/CO<sub>2</sub> monitors used for periodic inspections of vehicles in cites. The calibration was performed in the selected ranges: 900 - 12,000 µmol/mol for CO and 2000 - 20,000 µmol/mol for CO<sub>2</sub>. The traceability of the measurement results to the SI units was ensured by using certified reference materials from CO/N<sub>2</sub> and CO<sub>2</sub>/N<sub>2</sub> primary gas mixtures. The method performance was evaluated by assessing its linearity, accuracy, precision, bias, and uncertainty of the calibration results. The calibration data exhibited a strong linear trend with R² values close to 1, indicating an excellent fit between the measured values and the calibration lines. Precision, expressed as relative standard deviation <i>(%RSD),</i> ranged from 0.48 to 4.56% for CO and from 0.97 to 3.53% for CO<sub>2</sub>, staying well below the 5% threshold for reporting results at a 95% confidence level. Accuracy measured as percent recovery, was consistently high (≥ 99.1%) for CO and ranged from 84.90% to 101.54% across the calibration range for CO<sub>2</sub>. In addition, the method exhibited minimal bias for both CO and CO<sub>2</sub> calibrations and thus provided a reliable and accurate approach for calibrating CO/CO<sub>2</sub> monitors used in vehicle inspections. Thus, it ensures the effectiveness of exhaust emission control for better environment.
%K Monitors
%K Periodic Inspection
%K CO/CO&lt
%K sub&gt
%K 2&lt
%K /sub&gt
%K Calibration
%K Linearity
%K Precision
%K Accuracy
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=133415