person shall assume the title public weighmaster or any title of similar import, perform the duties or acts to be performed by a public weighmaster under this Chapter, hold himself out as a public weighmaster, issue any weight certificate, ticket, memorandum or statement for which a fee is charged or engage in the full-time or part- time business of public weighing, unless he holds a valid license as a public weighmaster. Public weighing, as used in this Section, shall mean the weighing for any person, upon request, of property, produce, commodities or articles other than those which the weigher or his employer, if any, is either buying or selling.