Formal recognition by an authoritative body that a calibration or testing laboratory is competent to perform specific types of measurements, typically assessed against ISO/IEC 17025.
Accreditation is the third-party attestation that a laboratory meets established standards of competence and quality. In calibration, accreditation bodies such as A2LA, NVLAP, or UKAS assess laboratories against ISO/IEC 17025 requirements and grant accreditation for specific scopes of measurement. The accreditation scope defines exactly which measurements the laboratory is recognized to perform and the best uncertainty (CMC) it can achieve for each.
The accreditation process involves a thorough document review, on-site assessment by technical experts, evaluation of the laboratory's quality management system, witness of actual calibration procedures, and review of uncertainty budgets. Accreditation is not a one-time event — accredited laboratories undergo regular surveillance assessments and periodic reassessments to maintain their accreditation status.
For calibration management, understanding accreditation is vital for selecting calibration service providers and for internal laboratories seeking to demonstrate competence. Accredited calibrations carry greater weight in audits and regulatory inspections. The scope of accreditation should be checked to ensure it covers the specific measurements needed — a laboratory accredited for DC voltage is not necessarily accredited for AC voltage. Many industries, including aerospace (AS6171), defense, pharmaceutical, and automotive, require or strongly prefer accredited calibration services.
In aerospace calibration labs, accreditation typically covers dimensional measurement tools like coordinate measuring machines (CMMs) and optical comparators used for critical flight components. A Pratt & Whitney supplier must maintain A2LA or NVLAP accreditation for torque wrench calibration up to 1000 ft-lbs to meet AS9100 requirements. The accreditation scope explicitly lists measurement capabilities with associated uncertainties - for example, 'Force: 10 N to 50 kN, uncertainty ±0.15%' for load cell calibration. Medical device manufacturers require ISO/IEC 17025 accreditation for biocompatibility test equipment calibration. A cardiac pacemaker manufacturer's environmental chamber calibration (temperature: -40°C to +85°C, ±0.5°C) must be within accredited scope to satisfy FDA 21 CFR 820 requirements. Common audit findings include performing measurements outside accredited scope - like calibrating a 2000 ft-lb torque wrench when accredited only to 1500 ft-lbs, or missing traceability documentation for reference standards. These violations can halt production and require expensive re-validation of affected products, particularly in aerospace where parts may need re-inspection or scrapping.
ISO/IEC 17025:2017 Section 4.1.5 requires laboratories to only claim accreditation for activities within their scope. AS9100D Section 7.1.5.1 mandates that calibration be performed by accredited laboratories or equivalent. ISO 13485:2016 Section 7.6 requires measurement equipment validation by competent laboratories, typically interpreted as accredited facilities. IATF 16949 Section 7.1.5.1.1 specifically requires external calibration laboratories to be accredited to ISO/IEC 17025 or national equivalent. ANSI/NCSL Z540.3-2006 Section 4.2 allows acceptance of accredited laboratory services as meeting calibration requirements. ILAC-P15:2013 provides application guidance for ISO/IEC 17025 accreditation. Auditors verify the calibration provider's accreditation certificate is current, covers the specific measurement parameters and ranges performed, and includes appropriate uncertainty statements. They examine whether the laboratory's measurement capabilities align with customer requirements and check for any measurements performed outside accredited scope, which constitutes a major nonconformity under most quality management standards.
CalibrationOS's Vendor Management module maintains digital copies of each calibration provider's accreditation certificates and automatically alerts users 60 days before expiration. The system validates that each calibration service request falls within the laboratory's accredited scope by comparing instrument specifications against the provider's measurement capabilities database. During certificate generation, the software automatically includes the calibration laboratory's accreditation number and scope reference. The Audit Trail feature creates compliance reports showing that all calibrations were performed by appropriately accredited laboratories, with links to current accreditation certificates. For internal laboratory operations, the Asset Management module tracks which measurement standards and procedures are covered under the laboratory's own accreditation scope, preventing technicians from issuing certificates for out-of-scope work. The system generates accreditation compliance dashboards for quality managers, highlighting any gaps between operational needs and current accredited capabilities, enabling proactive scope expansion requests before audit findings occur.
Calibration lab accreditation is formal recognition by an accreditation body (such as A2LA or NVLAP) that a laboratory meets ISO 17025 requirements for specific measurement capabilities, verified through on-site assessments.
Check the accreditation body's website for the laboratory's scope of accreditation. This document lists the specific measurements the lab is accredited for and the best uncertainty (CMC) it can achieve for each.
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