Test equipment must be calibrated against national reference standards (such as NIST).
Moving away from high-maintenance mechanical meters toward Coriolis (mass flow) and Magnetic flowmeters, which offer no moving parts and exceptional accuracy. Test equipment must be calibrated against national reference
Essentials of Modern Measurements and Final Elements ... - ISA Test equipment must be calibrated against national reference
The future is not maintenance free in the sense of neglect, but maintenance free from surprise failures . And that is a goal worth engineering for. Test equipment must be calibrated against national reference