These documents describe the accreditation requirements specifically applicable for calibration laboratories, both for those providing measurement standards calibration and for those performing measuring and test equipment (M&TE) calibration. The calibration program is based on ISO/IEC 17025-2005, General requirements for the competence of calibration and testing laboratories along with specific requirements from our Calibration Laboratory Accreditation Program.

• Calibration Program Requirements
• Calibration Checklist
• Calibration Selection List
• Policy on Measurement Uncertainty in Calibration (P110)
• Technical Consensus Decisions from the Measurement Advisory Committee (P109)
• Dimensional Testing Parameters on Scopes of Accreditation (R205c)
• Applications for Calibration Scopes of Accreditation (R218)
• Editorial Considerations for Scopes of Accreditation (R218a)
• Presentation of Durometers on a Scope of Accreditation (R218b)
• Presentation of Hardness on a Scope of Accreditation (R218c)

Calibration laboratories may also elect accreditation to the American national standard ANSI/NCSL Z540-1-1994 as an optional accreditation. See the Calibration Program Requirements for more information.

The optional accreditation to ANSI/NCSL Z540.3-2006 is also available. The additional requirements can be found in R205a - Annex to Specific Requirements: ANSI/NCSLI Z540.3-2006 and in the corresponding checklist C207a - Annex to Specific Checklist: ANSI/NCSLI Z540.3-2006.
Additional resources may be found at the following:

• For a free copy of ILAC G8:03/2009 see http://www.ilac.org/documents/ILAC_G8_03_2009.pdf
• A2LA Newsletter article - "How to Conduct a Reverse Traceability Study"
• Guidance on Pitch Diameter and Simple Pitch Diameter (G111)
• Guidance on 5700A, 5720A and 3458A Artifact Calibration (G112)
• FAQs for Endorsed Calibration Certificates
• To purchase a copy of ANSI/NCSLI Z540.3-2006: http://www.ncsli.org/core/orders/product.aspx?catid=45&prodid=651
• To purchase a copy of the handbook to ANSI/NCSLI Z540.3-2006: http://www.ncsli.org/core/orders/product.aspx?catid=45&prodid=494
• To review a white paper on Risk Analysis Methods for Complying with Z540.3 click here
• A free copy of the spreadsheets for the six methods of probability of false accept as outlined in the handbook are available here

Laboratories seeking accreditation for calibrations performed at other than the fixed laboratory location must complete the Field Testing & Calibration Program Requirements Checklist and submit it with the application. 

Preparing for Accreditation

Accreditation Process Summary

Application Materials

Explanations for the ISO/IEC 17025 Requirements

In addition to the technical documents list above, all laboratories seeking or maintaining A2LA accreditation must comply with all policy and requirements documents listed below. Where applicable, these documents must be completed prior to the start of the accreditation process.

1. Order ISO 17025. The A2LA Board of Directors has issued a policy requiring all laboratories to have an official copy of ISO/IEC 17025. Laboratories are being asked to confirm, in writing to A2LA, that the official copy is available on-site. Please print, and fill out form F102 – Ownership Confirmation: ISO/IEC 17025, and return to A2LA.
2. Print and complete the F101 - Application for Accreditation: ISO/IEC 17025 Laboratories. A2LA Document I109 - Fields of Accreditation for ISO/IEC 17025 Laboratories provides instructions on filling out Part II Section B of F101.
3. Review the Explanations for the ISO/IEC 17025 Requirements web page. This section presents A2LA’s official applications of the ISO/IEC 17025 requirements. It is expected that laboratories will implement the requirements of the standard in accordance with the applications listed here. Otherwise, areas of non-conformance will be identified by the assessor during the on-site assessment.  To have the latest updates delivered to you directly, please subscribe to the RSS feed.
4. Review the R101 - General Requirements: Accreditation of ISO/IEC 17025 Laboratories.
5. Print, review, sign and submit the R102 - Conditions for Accreditation.
6. Review the R103 - General Requirements: Proficiency Testing for ISO/IEC 17025 Laboratories and R103a - Annex: Proficiency Testing for ISO/IEC 17025 Laboratories. Please investigate and participate in proficiency testing as soon as possible.
7. Review the P102 - A2LA Policy on Measurement Traceability. To locate an acceptable source of calibration services, please search the A2LA Scopes of Accreditation. Alternatively, you can choose a calibration laboratory that is accredited by one of our mutual recognition arrangement partners.
8. Review the P101 - Reference to A2LA Accredited Status-A2LA Advertising Policy.
9. If your laboratory performs testing and/or calibration at sites other than your permanent laboratory premises, print out the Field Testing/Calibration R104 - General Requirements: Accreditation of Field Testing and Field Calibration Laboratories and C103 - General Checklist: Accreditation of Field Testing and Field Calibration Laboratories (word).
10. Additional Policies that may be applicable:
    • P103 - Policy on Estimating Measurement Uncertainty for Testing Laboratories and field-specific annexes to the measurement uncertainty policy
    • P104 - Policy for Claims of Measurement Uncertainties for Field Calibrations on Scopes of Accreditation