Miss. Code Ann. § 19-27-35: Miss. Code Ann. § 19-27-35

The county surveyor shall annually adjust any instrument used by him in making surveys after checking said instrument with the line of the true meridian established under Section 19-27-33 , or with the line of the true meridian established within said county by the United States Coast and Geodetic Survey, or a division designated by the survey, or with the line of the true meridian established by the Mississippi State Highway Department in the district in which the property to be surveyed is located. A surveyor shall not be allowed to certify or testify to the correctness of a survey thereafter made unless the instrument used in making it had been corrected and adjusted within twelve months next before the survey.