Alphasense 4-electrode air quality sensors provides OEMs with reliable sensors for use in Air Quality. Networks where very low parts per billion (ppb) detection levels are required. High sensor gain, fourth electrode compensation, advanced filtering (patents pending) and electrodes optimised for long term repeatability provide the needed sensitivity, selectivity and stability. With over eight years’ experience working with air quality networks, Alphasense is your partner when developing and supplying air quality networks.

Nitrogen Dioxide and Ozone are the two critical oxidising gases when monitoring air quality. Both gases cause oxidative stress to lung cells but the regulated levels are different so it is important to separate Ozone and Nitrogen Dioxide concentrations. The patented (and patent pending) Alphasense solution is to combine the Nitrogen Dioxide (NO2-B42F or NO2-A42F) and oxidising gas (OX-B421 or OX-A421) sensors as a pair: the NO2 sensor measures only NO2 and the difference between the two sensors gives the Ozone concentration. Gas concentrations for both O3 and NO2 are typically 20 to 200 ppb at the roadside, so good design of the sensor, housing and electronics plus intelligent data analysis are all required.
The B series sensors are designed for use in urban air fixed site networks while the A series sensors are designed for portable use and indoor air quality networks. Since low noise electronics are needed to get full sensor performance, Alphasense offers the AFE potentiostat circuit family for the A series and ISB potentiostats for B series sensors. Use them as a benchmark during development or as the analog interface to your A/D converter.