Using State Metrology Labs
Having weights (mass) re-calibrated by a commercial metrology (calibration) laboratory is often cost prohibitive (i.e., it's cheaper to purchase new certified weights). However, many taxpayer-funded State operated metrology laboratories (e.g., State Dept. of Agriculture) offer inexpensive calibration of weights (aka mass). Check the fees from your State Metrology lab before purchasing new weights.
Texas Department of Agriculture – Metrology Program Standard Calibration Services and Fee Schedule
Louisiana Department of Agriculture and Forestry – Metrology
Kansas Department of Agriculture – Metrology Lab
Arkansas Department of Agriculture – State Mass/Volume Lab
For a complete list (with general contact information), visit: https://www.nist.gov/pml/owm/weights-and-measures-resources/state-metrology-laboratories
NIST GMP 11 – Good Measurement Practice for Assignment and Adjustment of Calibration Intervals for Laboratory Standards, “Table 3. Recommended calibration intervals for mass standards for Echelon III calibrations” provides for good initial calibration intervals. Where check weights (mass) are only used to calibrate (or verify) the accuracy of weighing scales 2 or 3 times a year, these are typically placed on an extended calibration interval due to their seldom use and minimal wear (provided that they're not mishandled or damaged).
Read “Reducing Waste: Through Optimizing Calibration Intervals” for detailed information on how to justify extending calibration intervals.
