Evaluation of low-cost electro-chemical sensors for environmental monitoring of ozone, nitrogen dioxide, and carbon monoxide

Details

• Alternative Title:
  J Occup Environ Hyg
• Personal Author:
  Afshar-Mohajer, Nima ; Zuidema, Christopher ; Sousan, Sinan ; Hallett, Laura ; Tatum, Marcus ; Rule, Ana M. ; Thomas, Geb ; Peters, Thomas M. ; Koehle, Kirsten
• Description:
  Development of an air quality monitoring network with high spatio-temporal resolution requires installation of a large number of air pollutant monitors. However, state-of-the-art monitors are costly and may not be compatible with wireless data logging systems. In this study, low-cost electro-chemical sensors manufactured by Alphasense Ltd. for detection of CO and oxidative gases (predominantly O| and NO|) were evaluated. The voltages from three oxidative gas sensors and three CO sensors were recorded every 2.5 sec when exposed to controlled gas concentrations in a 0.125-m| acrylic glass chamber. Electro-chemical sensors for detection of oxidative gases demonstrated sensitivity to both NO| and O| with similar voltages recorded when exposed to equivalent environmental concentrations of NO| or O| gases, when evaluated separately. There was a strong linear relationship between the recorded voltages and target concentrations of oxidative gases (R| > 0.98) over a wide range of concentrations. Although a strong linear relationship was also observed for CO concentrations below 12 ppm, a saturation effect was observed wherein the voltage only changes minimally for higher CO concentrations (12-50 ppm). The nonlinear behavior of the CO sensors implied their unsuitability for environments where high CO concentrations are expected. Using a manufacturer-supplied shroud, sensors were tested at 2 different flow rates (0.25 and 0.5 Lpm) to mimic field calibration of the sensors with zero air and a span gas concentration (2 ppm NO2 or 15 ppm CO). As with all electrochemical sensors, the tested devices were subject to drift with a bias up to 20% after 9 months of continuous operation. Alphasense CO sensors were found to be a proper choice for occupational and environmental CO monitoring with maximum concentration of 12 ppm, especially due to the field-ready calibration capability. Alphasense oxidative gas sensors are usable only if it is valuable to know the sum of the NO| and O| concentrations.
• Subjects:
  Air Quality Article Field Calibration Gas Sensors Monitoring Network
• Source:
  J Occup Environ Hyg. 15(2):87-98
• Pubmed ID:
  29083958
• Pubmed Central ID:
  PMC6541011
• Document Type:
  Journal Article
• Funding:
  P30 ES005605/ES/NIEHS NIH HHS/United States ; R01 OH010533/OH/NIOSH CDC HHS/United States
• Volume:
  15
• Issue:
  2
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:7bebb33d49ecea7bbda9aad23185d1cecfcc202fff64cd033e8810e0f2e80d1e
• Download URL:
  https://stacks.cdc.gov/view/cdc/78809/cdc_78809_DS1.pdf
• File Type:
  [PDF - 936.03 KB ]