標準號：IS 5182 Pt.18-1974
發布日期：1975/2/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This standard (Part XVIII) covers the determination of low concentrations of oxidants in the atmosphere. The term ' oxidants ' as used in this standard refers to substances capable of liberating iodine from buffered, neutral potassium iodide solutions. The method is quantitative for ozone. Nitrogen dioxide and certain peroxidized compounds are also registered, but with low sensitivity. Reducing substances such as sulphur dioxide or hydrogen sulphide interfere with the determination by consuming iodine.1.2 The recorders are generally set up to indicate the range of 0 to 20 to 100 ppm of oxidant ( ozone ) on a logarithmic scale. This range can be modified by changing the gas-to-liquid ratio in the scrubber or the dimensions of the optical cell, or both.