Section 27A. Except as provided in section twenty-eight A with respect to emergency licensing, no person in determining the basis for payment in buying or selling shall measure, sample or accept raw milk at a dairy farm for inclusion in a bulk tank truck unless he has first obtained from the director or his agent a certificate indicating that he is competent in such operations and thereafter has been licensed under the provisions of section twenty-eight A. The fee for such a certificate of competency shall be set by and be payable to the director. The director shall establish such requirements with respect to the application for and granting of said certificates as he deems appropriate. A copy of each such certificate shall be furnished to the said chief of the bureau of milk marketing.