Maryland Code, Agriculture § 11-405

(a) Every purchaser or hauler of milk or other fluid dairy products who is involved in the testing of samples shall have these operations performed only by individuals licensed by the Secretary.

(b) Any person who calibrates a farm milk tank, other than the owner of the tank, first shall obtain a license from the Secretary.

(c) Any individual required to obtain a license to calibrate farm milk tanks or test milk or other fluid dairy products shall apply to the Secretary and pay an examination fee. If the applicant satisfactorily passes an appropriate examination conducted by the Secretary, the applicant is entitled to receive the kind of license for which he qualifies upon the payment of a fee.

(d) Every license is valid for the license year for which it is issued unless revoked or suspended. Each license may be renewed annually without examination upon application and payment of a renewal fee.