PICTURE

Gas Sensor intro and why do research.

Mobile Air Quality Sensing (MAQS)

Ricardo Piedrahita, Nick Masson, Ashley Collier, Yifei Jiang, Kun Li, Xiang Yun

PICTURE

The MAQS project is working on using low-cost technology for continuous networked personal monitoring of carbon monoxide, carbon dioxide, ozone, nitrogen dioxide, and volatile organic compounds. Multiple monitoring instruments have been developed within the group utilizing the low-cost gas phase sensors used in the MAQS personal exposure sampler. Of note is the group's continued development of high quality calibration techniques for these sensors.

Additional Projects Using Low-Cost Gas-Phase Sensors:

Cooking up Clean Air -- Scaled-up Air Quality and Health Impacts of Clean Cookstoves in Ghana.  

Investigating the health benefit of solar powered lighting vs. traditional kerosene lamps in rural Ugandan dwellings.

Sensor Array Project for Monitoring Complex Mixtures of Gases

John Ortega

John Ortega is currently working on using multiple low-cost gas-phase sensors to identify individual carbonaceous compounds in a mixture. You can find a summary of his work here. Shown below (left) is the calibration set up where different gasses (such as gasoline vapor, methane, CO, or other volatile organic compounds) are mixed with air in specific quantities to study the effects of the different sensors to these gases. The system is controlled with a laptop, USB-based DAQ, mass flow controllers, and some other minor electronics. Gasses can be tested individually or in combined ratios. They are mixed with zero-grade air to achieve realistic concentrations in the ppb to ppm range. The sensor array containing a mixture of metal-oxide sensors made by E2V Technologyies and Figaro is also shown below on the right. Also included in the array is a photo-ionization detector made by Baseline Mocon. The interaction of the individual units are used to separate the signals of each constituent gas in the mixture.

Natural Gas Emission Monitoring

Joanna Gordon

DESCRIPTION

Dry-Deposition-Flux Chamber

Berkeley Almand, Nick Masson, Ricardo Piedrahita

Our research group is working on developing inexpensive flux chambers to measure gas-phase dry deposition. Dry deposition occurs when gases or particles are deposited onto a surface (water, ground, vegetation, etc.) in the absence of precipitation. The deposition of compounds such as SO2, NO, NO2, HNO3, O3, and NH3 can damage vegetation and aquatic ecosystems. Dry deposition accounts 25-80% of atmospheric deposition (depending on location), and dry deposition measurements are expensive and/or complex. As a result, most regulatory sites do not measure dry deposition, but measure ambient concentrations and use models to determine fluxes. This method is problematic because the models can disagree with measurements by up to 100%. Our research effort addresses this issue by developing a robust, inexpensive, and continuous multiple-species gas-flux monitoring system, which will be able to provide data for a variety of relevant atmospheric pollutants.  We are working on developing inexpensive sensors ($5-100) for our flux chambers, as well as exploring the possibility of connecting the chambers to existing instruments. While working towards our ultimate goal of a complete instrument that costs less than $5000, we can use our chambers with existing instruments to take flux measurements at sites that could previously only measure concentration.

ASHLEY'S EJ PROJECT

PEOPLE 

PICTURE

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