Understanding ambient air quality instrument operating ranges
In order to maximize the performance of an air quality monitoring station, careful selection of instrumentations is essential. One of the key issues is to have a good understanding of what pollutants need to be measured and at what concentrations. There are several different types of air quality monitoring, these include:
This is performed in areas where there is no immediate source of pollutants, such as motor vehicles or industry and is aimed at obtaining “background” measurements for that region.
These stations typically measure a wide range of pollutants including PM10, PM2.5, O3, CO, NOy, NO2, NO, SO2 and meteorological conditions.
Concentrations for CO are typically less than 100 ppb and often less than 1 ppb for all other gases. PM concentrations are also low, often less than 10 ug/m3 for PM10 and 5 ug/m3 for PM2.5.
This application calls for special trace monitoring analysers capable of measuring at these very low concentrations.
This is performed in urban locations but removed from any immediate source of pollutants and is aimed at providing a good understanding of typical pollutant concentrations in the broad area. A typical city of a population of around 5 million, may have anywhere between 10 to 30 of these monitoring stations depending on local topography and available funding.
These monitoring stations measure “criteria” pollutants, which are gases that include O3, CO, NO2, SO2 and particulates such as PM10 and in some countries PM2.5.
The goal for these stations is to ensure that “typical” pollution concentrations don’t exceed that countries standards and thus do not impact on the health and wellbeing of the population.