1.1 This test method covers the manual determination of the combined nitrogen dioxide (NO₂) and nitric oxide (NO) content, total NO_x; in the atmosphere in the range from 4 to 10000 ug/m₃ (0.002 to 5 ppm (v)).

1.2 The maximum sampling period is 60 min at a flow rate of 0.4 L/min.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.