INTRODUCTION
This section covers the monitoring of ambient air quality. Air sampling is discussed, but the same subject is also covered in more detail in Section 8.2. Particulate and opacity monitoring are not covered here, as those topics are discussed in a later section in this chapter. This section starts with a general discussion of air quality monitoring systems and continues with a description of air quality detecting sensors, automatic monitoring packages, and microprocessor-based portable ambient air analyzers. The section is concluded with a discussion of ambient air sampling for both gases and particulate matter.

AIR QUALITY MONITORING SYSTEMS

There are many options for the types of air quality information that can be collected, and the cost of air quality monitoring systems can vary by orders of magnitude. Only with a thorough understanding of the decisions that must be made based on the information received from the air quality monitoring  can an appropriate selection be made. Regardless of the type of instruments used to measure air quality, the data are only as good as they are representative of the sampling site selected. See Table 8.5a for a list of air quality and meteorological parameters and their measurement ranges, accuracy, and method of analysis.