15A NCAC 02D .2606 MOLECULAR WEIGHT (a) With the exceptions allowed under Paragraph (b), Method 3 of Appendix A of 40 CFR Part 60 shall be applied as written and used concurrently with any test method when necessary to determine the molecular weight of the gas being sampled by determining the fraction of carbon dioxide, oxygen, carbon monoxide, and nitrogen. (b) The grab sample technique may be substituted using instruments such as Bacharach FyriteTM with the following restrictions: (1) (2) (3) History Note: Instruments such as the Bacharach FyriteTM may only be used for the measurement of carbon dioxide. Repeated samples shall be taken during the emission test run to account for variations in the carbon dioxide concentration. At least four samples shall be taken during a one-hour test run, but as many as necessary shall be taken to produce a reliable average. The total concentration of gases other than carbon dioxide, oxygen, and nitrogen shall be less than one percent. Authority G.S. 143-215.3(a)(1); 143-215.65; 143-215.66; 143-215.107(a)(5); Eff. June 1, 2008.