I only have my standard check weights certified, and the auditor was ok with it. I did go overboard and provided all relevant regulatory information and the auditor was happy with it. Info below was very helpful in justifying this decsion.
https://laws-lois.justice.gc.ca/eng/Regulations/C.R.C.,_c._1605/index.html
https://www.nist.gov...current-edition
NIST Handbook 44 Specifications, Tolerances, And Other Technical Requirements for Weighing and Measuring Devices
3.3. Accuracy of Standards. - Prior to the official use of testing apparatus, its accuracy should invariably be verified. Standards should be re-verified as often as circumstances require. By their nature, metal volumetric standards are more susceptible to damage in handling than are standards of some other types. A standard should be re-calibrated whenever damage is known or suspected to have occurred or significant repairs have been made. In addition, standards, particularly volumetric standards, should be re-calibrated with sufficient frequency to affirm their continued accuracy, so that the official may always be in an unassailable position with respect to the accuracy of his testing apparatus. Secondary standards, such as special fabric testing tapes, should be verified much more frequently than such basic standards as steel tapes or volumetric provers to demonstrate their constancy of value or performance. Accurate and dependable results cannot be obtained with faulty or inadequate standards. If either the service person or official is poorly equipped, their results cannot be expected to check consistently. Disagreements can be avoided, and the servicing of commercial equipment can be expedited and improved if service persons and officials give equal attention to the adequacy and maintenance of their testing apparatus.
NIST Handbook 105-1- Specification and Tolerance, for Reference Standards and Field Standard Weights and Measures.