For accreditation, labs must demonstrate compliance with ANSI/NCSL Z540.3 requirements regarding measurement and test equipment, accuracy, and service performance. Guidelines are also provided for aspects of calibration, such as measurement uncertainty, document control and service intervals. Operating in full compliance with the standard allows labs to better control calibration risks.
The term ANSI Z540 or NCSL Z540 may be used in reference to either ANSI/NCSL Z540-1 or ANSI/NCSL Z540.3. The Z540-1 calibration standard was the original version from 1994. Though withdrawn as an active standard in 2007, Z540-1 calibrations continue to be offered by labs for customers who have this type of servicing need.
ANSI Z540 and the PFA