Section 60.2255 - How must I monitor opacity for air curtain incinerators?(a) Use Method 9 of appendix A of this part to determine compliance with the opacity limitation.(b) Conduct an initial test for opacity as specified in § 60.8 .(c) After the initial test for opacity, conduct annual tests no more than 12 calendar months following the date of your previous test. 81 FR 40970, 6/23/2016; 84 FR 15853, 4/16/2019