CFR /  Title 40  /  Part 60  /  Sec. 60.2255 How must I monitor opacity for air curtain

(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 Sec. 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.