Mass. Gen. Laws ch. 98 § 41
Sealers shall annually give public notice, by advertisement or by posting notices in one or more public places in their towns or districts, to all inhabitants, or persons having usual places of business therein, using weighing or measuring devices for the purpose of buying or selling goods, wares or merchandise, for public weighing or for hire or reward, to bring them in to be tested, adjusted and sealed, excepting that pick clocks on looms in textile factories, required by section one hundred and fifty-six of chapter one hundred and forty-nine, shall be tested on the request of either an employer or an employee, or both, or, in any event, at the discretion of the director of consumer affairs and business regulation or his authorized representatives. Such sealers shall attend in one or more convenient places, and shall adjust, seal or condemn such devices in accordance with the results of their tests, and shall make a record thereof.
Mass. Gen. Laws ch. 98, § 41