Tenn. Code § 47-26-1108
A registered serviceperson and a registered service agency shall submit, at least biennially (every two (2) years) to the commissioner, for examination and certification, any standards and testing equipment that is used, or to be used, in the performance of the service and testing functions with respect to weighing and measuring devices for which competence is registered. A registered serviceperson or agency shall not use in servicing commercial weighing or measuring devices any standards or testing equipment that has not been certified by the commissioner. Standards calibrated by another state weights and measures laboratory that can show current traceability to the National Institute of Standards and Technology will also be recognized as standards suitable for use by registered servicepersons or service agencies in this state. Copies of laboratory certificates from another state weights and measures lab must be submitted along with serviceperson license application forms when applying for registration in this state.
T.C.A. § 47-26-1108