Part of my daily routine includes fielding telephone calls and retrieving e-mail from shops across the country involved in gage calibration. Many of the inquirers pose questions like these: "Is the standard we are working to still valid?" "Which standard applies to our operation?" "Which is the most current standard?" With all the changes and revisions in standards over the past five years, particularly the cancellation of the military standard MIL-STD45662A in 1995, I can understand the confusion. Here is an overview of the current metrology standards.
ISO 10012-1-1992, Quality Assurance Requirements for Measuring Equipment. Specifies the requirements for the assurance of measurement accuracy in a quality system. Applies to measuring equipment used to demonstrate compliance with a specification.
ISO-IEE Guide 25:90, General Requirements for the Competence of Calibration and Testing Laboratories. The international standard for accrediting calibration and testing labs. Will be superseded by ISO 17025.
ANSI/NCSL Z540-1-94, American National Standard for Calibration. The U.S. national equivalent to ISO Guide 25; effectively replaced MIL-STD45662A as the calibration-system requirements standard for U.S. industry.
ANSI/NCSL Z540-2-97, American National Standard for Expressing Uncertainty. Covers how to compute and document measurement uncertainty for calibration certificates.
ISO-14253-2, Geometrical Product Specifications. Provides a uniform method for expressing measurement uncertainty and applying it to acceptance/rejection of features.
ANSI/ASQC M1-1996, American National Standard for Calibration Systems. The ASQ-published successor for organizations transitioning away from MIL-STD45662A toward Z540-1.
Documents can be purchased from ANSI (American National Standards Institute) or ASQ (American Society for Quality).