New York Consolidated Laws, Civil Practice Law and Rules - CVP Rule 4534. Standard of measurement used by surveyor

An official certificate of any state, county, city, village or town sealer elected or appointed pursuant to the laws of the state, or the statement under oath of a surveyor, that the chain or measure used by him conformed to the state standard at the time a survey was made is prima facie evidence of conformity, and an official certificate made by any sealer that the implement used in measuring such chain or other measure was the one provided the sealer pursuant to the provisions of the laws of the state is prima facie evidence of that fact.