Me. Rev. Stat. tit. 10, § 2502 (2025)
When making a weight determination as provided for by this chapter, a licensed public weighmaster shall use a weighing device that is of a type suitable for the weighing of the amount and kind of material to be weighed and that has been tested and approved for use by the state sealer or a sealer within a period of 12 months immediately preceding the date of weighing.