Section 85. The mayor or the selectmen, on the written request of any person engaged in buying, selling or transporting goods or commodities which require weighing, surveying or measuring, shall appoint weighers, measurers or surveyors of such goods or commodities, who shall be sworn before entering upon their duties, shall serve for one year, and may be removed at any time by the appointing authority. At least one such weigher, measurer and surveyor in each town shall not be engaged in the business of buying, selling or transporting the goods or commodities weighed, measured or surveyed by him, but no person shall be ineligible for appointment because of sex or because of residence elsewhere than in the town where appointed, notwithstanding any provisions to the contrary in any general or special act.