You are here:
METHODOLOGY AND INSTRUMENTATION TO MEASURE GASEOUS AMMONIA
Citation:
David, D., M. Willson, AND D. Ruffin. METHODOLOGY AND INSTRUMENTATION TO MEASURE GASEOUS AMMONIA. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-77/125.
Description:
Methodology for the time integrated collection and analysis of atmospheric ammonia was developed. Ammonia is primarily measured because it can react with SOx to produce ammonium sulfate. Since SOx is one of the principle air pollutants, it is important to determine its atmospheric reactions. The methodology makes use of optical wave guides which are 1 x 20 mm quartz rods coated with a chemical that is specific for NH3. As ammonia reacts with the chemical on the rod, the optical properties of light passing through the rod change and can be directly related to the NH3 concentration. An optical wave guide analyzer was developed to measure the resulting change in optical properties. Concentrations as low as 1 ppb can be assayed. The coated quartz rods are placed in the field for 24 hours and brought back to the laboratory for analysis by the analyzer.