The purpose of this document is to prescribe and establish procedures to be used in the development and publication of certified performance ratings for airflow measurement stations. Certified ratings provide assurance to the buyer, user and specifier that the manufacturer's published performance ratings for airflow measurement stations are repeatable. The ratings also provide information on how the product was tested, what appurtenances (accessories or optional equipment) were accounted for in the ratings and other pertinent information. This publication provides a procedure for the verification of the manufacturer's performance ratings on a regular schedule through check-testing of products in the AMCA International laboratory. The publication also provides assurance that competitive ratings are comparable at the point where the output data is acquired and that they are based on standard test methods on ratings procedures. This publication is an extension of the AMCA Certified Rating Program. Information on the operation of the program is given in AMCA Publication 11, Certified Ratings Program ' Operating Manual.