CRITERIA FOR PERFORMING CALIBRATION AND INTERMEDIATE CHECKS ON EQUIPMENT USED IN ACCREDITED FACILITIES Approved By: Chief Executive Officer: Ron Josias Senior Manager: Mpho Phaloane Reviewed By: Field Manager: Neville Tayler Date of Approval: 2015-11-17 Date of Implementation: 2015-11-17 SANAS Page 1 of 6
CONTENTS: 1. Purpose and Scope... 3 2. Definitions and References... 3 3. General... 3 3.1 SANAS Policy on Metrological Traceability... 3 3.2 Reference Materials / Consensus Standards... 3 3.3 In-House Calibrations... 4 3.4 Requirements for Calibration... 4 3.5 Intermediate Checks... 4 3.6 Non-accredited Calibration Service Providers... 5 ADDENDUM 1: AMENDMENT RECORD... 6 SANAS Page 2 of 6
1. Purpose and Scope The purpose of this document is to specify criteria for performing calibration and intermediate checks on equipment used in facilities accredited by the South African National Accreditation System (SANAS). This document applies to all SANAS accredited facilities. 2. Definitions and References Act 18, 2006 Measurement Units and Measurement Standards Act, 2006 Act 19, 2006 Accreditation for Conformity Assessment, Calibration and Good Laboratory Practice Act SANAS PM 01 SANAS Policy Manual SANAS A01 References, Acronyms and Definitions ISO/IEC Guide 99 International vocabulary of metrology - Basic and general concepts and associated terms (VIM) ILAC P10 ILAC Policy on Traceability of Measurement Results 3. General 3.1 SANAS Policy on Metrological Traceability The general SANAS policy on metrological traceability is addressed in the SANAS Policy Manual PM 01. The policy defines the acceptance for traceability purposes of: calibration certificates and reports issued by SANAS accredited calibration laboratories; certificates issued by laboratories accredited by full members of the ILAC arrangement; calibration certificates issued by the National Metrology Institute of South Africa (NMISA); and calibration certificates issued by members of the International Committee of Weights and Measures (CIPM) arrangement, whose Calibration and Measurement Capabilities (CMC s) are accepted into the International Bureau of Weights and Measures (BIPM) Key Comparison Database (KCDB). The policy also makes provision, under specific circumstances for the acceptance of certificates issued by National Metrology Institutes (NMI s) whose CMC s have not yet been submitted or accepted into the BIPM KCDB. 3.2 Reference Materials / Consensus Standards SANAS acknowledges that it is not always possible or realistic to expect all measurements to be traceable to the International System of Units (SI), for example, traceability may be to a Certified Reference Material (CRM), or a specified method and/or consensus standard. Participation in a suitable program of interlaboratory comparisons / proficiency testing is a requirement. Where traceability is established through the use of reference materials, traceability is accepted if the Reference Materials (RMs) are included in the BIPM KCDB, or have been produced by a Reference Material Producer (RMP) accredited to ISO Guide 34 in combination with ISO/IEC 17025. Where RMs are covered by the Joint Committee for Traceability in Laboratory Medicine (JCTLM), these are also considered as having established valid traceability. Where reference materials do not meet the above criteria, they are required to be treated as critical consumables, and the facility is required to demonstrate that each RM is suitable for its intended use. SANAS Page 3 of 6
3.3 In-House Calibrations In-house calibrations are considered as being those calibrations performed by a facility on their own premises on their own test and measurement equipment. For all In-house calibrations the facility is required to maintain as a minimum the following: a documented and validated calibration procedure or method; a calibration certificate or report, or some other suitable method of recording the calibration and measurement data; appropriate educational and training records to demonstrate the competence of the personnel performing the calibration; copies of certificates and reports to demonstrate traceability to the SI system of units or RMs as per 3.1 & 3.2 above; all reference standards and measuring instruments shall be calibrated at appropriate intervals, the facility shall have and apply a documented procedure for establishing these calibration intervals; a documented procedure for the estimation of the measurement uncertainty, which shall be applied for at least each type of calibration. The uncertainty of measurement shall be taken into account when making a statement of compliance. records to demonstrate the assurance of the calibration results i.e. participation in Inter-Laboratory Comparisons or Proficiency Testing; documented requirements for environmental conditions, and records where applicable; and evidence of internal audits of all activities that could influence the quality of calibration results. As calibration laboratories are accredited for the purpose of passing on metrological traceability through an unbroken chain of comparisons, in-house calibration by a calibration laboratory is only acceptable where the laboratory has been accredited for the specific inhouse calibration performed. Where equipment within a calibration laboratory is used solely as a transfer device it is not necessary for the laboratory to be accredited for the calibration of this transfer device. For example when a balance is used to calibrate weights; and the process of the calibration involves the process of the comparison of two weights, the standard and the unit under test it is not necessary that the laboratory be accredited for the calibration of the balance, which is used solely as a transfer device. 3.4 Requirements for Calibration All equipment and measuring instruments used to perform testing and measurement within a facility, including subsidiary measurements, must be calibrated unless it can be demonstrated that they have an insignificant effect on the accuracy or validity of the measurement result. Records shall be available that demonstrate this. For the purposes of interpretation any item of test and measurement equipment, the uncertainty of which contributes less than 5% to the total uncertainty of measurement would be considered as insignificant. 3.5 Intermediate Checks Intermediate checks are those checks performed to maintain confidence in the calibration status of measuring and test equipment. Intermediate checks shall be conducted according to a defined procedure. Intermediate checks are not a substitute for calibration but may provide justification for the extension of calibration intervals, where results are favourable. When intermediate checks are performed appropriate records shall be maintained, and the uncertainty of measurement shall be considered when confirming if the calibration status continues to satisfy the requirements for the test or measurement. SANAS Page 4 of 6
3.6 Non-accredited Calibration Service Providers The use of non-accredited service providers, or service providers not meeting the requirements for traceability as per 3.1 above, are only permitted where no alternative accredited service provider is currently available. The use of such service providers is subject to the same requirements as for in-house calibrations, records of which must be available at the facility accredited or seeking accreditation. SANAS Page 5 of 6
ADDENDUM 1: AMENDMENT RECORD Proposed By: Section Change FM Cal 2 Add reference to Act 19, 2006 FM Cal 3.3 Include additional requirements as per ILAC P10:01/2013 for in-house calibrations. SANAS Page 6 of 6