N.Y. C.P.L.R. 4534

Rule 4534. Standard of measurement used by surveyor. An official\ncertificate of any state, county, city, village or town sealer elected\nor appointed pursuant to the laws of the state, or the statement under\noath of a surveyor, that the chain or measure used by him conformed to\nthe state standard at the time a survey was made is prima facie evidence\nof conformity, and an official certificate made by any sealer that the\nimplement used in measuring such chain or other measure was the one\nprovided the sealer pursuant to the provisions of the laws of the state\nis prima facie evidence of that fact.\n