R 336.2151 Calibration gases for continuous emission monitoring systems.

Rule 1151. (1) For nitrogen oxide monitoring systems installed on fossil fuel-fired steam generators, the pollutant gas used to prepare calibration gas mixtures shall be nitric oxide. (2) For sulfur dioxide monitoring systems installed on fossil fuel-fired steam generators or sulfuric acid plants, the pollutant gas used to prepare calibration gas mixtures shall be sulfur dioxide. (3) Span and zero gases shall be traceable to national bureau of standards reference gases when these reference gases are available. Every 6 months from the date of manufacture, span and zero gases shall be reanalyzed by conducting triplicate analyses using the reference method in appendix A of 40 C.F.R. Part 60, adopted by reference in R 336.1299, as follows: (a) For sulfur dioxide, use reference method 6. (b) For nitrogen oxides, use reference method 7. (c) For carbon dioxide and oxygen, use reference method 3. The gases may be analyzed at less frequent intervals if longer shelf lives are guaranteed by the manufacturer.