The performance capabilities and limitations of available and prototype sulfur-dioxide (7446095) (SO2) meters were studied. An attempt was made to determine the best techniques for using each meter in a field testing situation and to develop a recommended set of performance standards and quality control standards for such meters. Altogether, six meters were identified and tested, including the Casella SO2 Sampler T1400, the CO2 Ultra Portable Analyzer U2-DS, the Sulfur-Dioxide Analyzer S-364, the Microcoulomb Detector Model 724-21MS, the Titrilog-III, and the Miran-I Variable Filter Infrared Analyzer. Characteristics measured for each sampler included stability, drifts, linearity, response times, and specificity. Evaluations were also made of physical characteristics including portability, readout, instruction manuals, and ease of zero and span adjustments. Recommended performance and construction standards, and quality control standards were provided.