As well as calibrating your glossmeter on its own reference gloss tile before use, your glossmeter and its tile need to be calibrated yearly by a Rhopoint Approved Service Agent.  This ensures their accuracy, giving you full confidence that your product is performing correct and that measurements are up-to-date with the best available reference data and compliant to current industry standards.
The primary master gloss artefacts used in our calibrations are calibrated by the National Institute of Standards and Technology (NIST), USA in accordance with the best practices and data available, which are upgraded when appropriate. All of our gloss calibrations are therefore traceable to NIST, with documentation available on request.