The Ogawa Passive Sampler is manufactured and distributed worldwide by Ogawa & Company, USA, Inc. The sampler has seen use in a large number of air monitoring campaigns as well as specialized applications in indoor and outdoor environments. The system is currently available for the determination of NO, NO2, NOx, SO2 and O3 concentrations, with additional components planned for the future.
Key features of the sampler have been patented by Ogawa as the result of extensive field measurements to optimize performance. Extensive characterization by organizations such as the USEPA and the Harvard School of Public Health have shown excellent comparability between results from the Ogawa Passive Sampler and averaged measurements from continuous gas analyzers.
The system’s low cost and lack of power requirements makes it the ideal tool for determining the concentration of selected ambient gases at desired sampling locations. It can provide an effective means of determining the gradients in pollutant levels across an urban and/ or background area through “saturation” sampling at many sites. One longtime user in the US has been the National Park Service. It can be used as a personal sampler to assess the average exposure of individuals to selected pollutants over an 8- or 24-hour period.
Archives, national libraries and art museums employ the Ogawa Passive Sampler to track the levels of gaseous pollutants over time to protect their holdings.
The implementation of the sampler does not require highly skilled personnel, making it feasible to establish even large air sampling networks with minimal training without the need for conventional analyzer maintenance.
The Ogawa Passive Sampler is composed of a plastic body with an air inlet on either side. It is possible to sample more than one gas simultaneously, since the two inlets are separated by the solid section of the body. The dual-sided body is usually mounted on a clip that can be fastened to a person or installed in a protective outdoor shelter (see photos).
Two types of shelters are available for outdoor sampling: a smaller shelter for all gases except ozone (O3), and a larger shelter for O3 sampling that is suitable for other gases as well.