Ala. Code § 32-9-32
The Director of the Department of Transportation is authorized to designate, furnish instructions to, prescribe rules and regulations for the conduct of, and to supervise official stations for determining the weight of motor vehicles at such points as it may be deemed necessary. Such designated weighing devices shall be checked by the weights and measures division of the Department of Agriculture and Industries and certified to be correct within the tolerances prescribed under the rules and regulations established by the state Department of Agriculture and Industries, and checks shall be made at such points as is deemed necessary by the weights and measures division of the Department of Agriculture and Industries. All stations shall comply with the requirements of the director and shall be available for the use of all officers in the enforcement of this chapter. The expense of weighing such motor vehicles shall be paid out of any funds made available for the use of the state highway patrol. If it is found that any motor vehicle is being operated in violation of this chapter, the expenses of such weighing shall be taxed as part of the costs for the prosecution of such violation. A certificate issued by the chief of the division of weights and measures of the Department of Agriculture and Industries, signed by such official, under oath, and countersigned by the Commissioner of Agriculture and Industries, in which the chief of the division of weights and measures certifies that scales, or weighing devices, have been checked and approved as required under the provisions of this section and Section 32-9-31 and found to be correct, within prescribed tolerances, shall be received in any court as prima facie evidence of the fact that the scales or weighing devices designated and identified in such certificate have been checked and approved for accuracy in accordance with the requirements of this section and Section 32-9-31; provided, that such certificate must show that the scales or weighing devices were checked for accuracy within a period of four months (120 days) prior to the date on which the motor vehicle was weighed to determine whether such vehicle was being operated in violation of this chapter.
Ala. Code § 32-9-32 (1975)