A matter of calibration confidence

The ultimate recognition of credibility for commercial calibration agencies is ISO/IEC 17025 accreditation, as it is the only independent credential that embraces both key elements of sound management and technical competence.

Proper calibration of critical equipment is central to a company's service and reputation, whether it is a manufacturer, service provider, supplier or small business.

An incorrectly calibrated piece of critical equipment has a flow-on effect on products and services that can be devastating to both a business and that of its customers.

Product recalls and litigation are increasingly common outcomes that can be traced back to seemingly innocent pieces of measuring equipment operating quite happily outside their performance specifications.

What should be calibrated externally?

The Standards Australia /Standards New Zealand publication HB86.1 1996 Guide to the selection, care, calibration and checking of measuring instruments in industry, Part 1 provides guidance on the factors that need to be taken into account in deciding whether an instrument should be calibrated externally or in-house.

The factors include:

• The need for comparative quotes from external calibration laboratories which should either be the National Measurement Laboratory or an accredited laboratory.
• The cost of establishing an in-house calibration program, including equipment, reference standards and a suitable environment.
• The need and cost of training staff to perform the calibrations in-house.

It is usually up to the quality or technical manager to decide what are the critical instruments or equipment that need external expertise to calibrate properly, or need calibration certificates supplied by a reliable agency to satisfy traceability, legal, international or certification requirements.

Unfortunately, calibration is occasionally viewed by organisations as an undesirable overhead rather than as a quality assurance tool.

As such, calibration can often be seen as an imposition by an outside party or as a habitual, but not intrinsically valuable activity, rather than as an integral part of an organisation's overall quality management system.

It can also be forgotten that proper calibration of instrumentation and equipment relies heavily on the skill, expertise and technical knowledge of the individual performing the calibration.

The risk of not doing the calibration correctly by trying to save money and do it in-house, versus the downstream consequences of defective goods, loss of business and reputation, due diligence and litigation must be considered in reaching a decision on each particular item.

What should you look for?

If the decision is made to engage an external calibration service, HB86.1 1996 section 5.5.2 (e) notes that the contracted agency should be able to provide a calibration which is:

• Traceable to national physical standards
• Conducted by trained and technically competent staff
• Conducted in an appropriately controlled environment and
• Conducted using recognised calibration procedures.

The guide also stresses the importance of selecting a NATA accredited agency as "evidence that the calibration has been performed with traceability to national physical standards or measurement and that the laboratory is assessed periodically for its competence to perform the calibration".

When accepting a calibration certificate, there are certain things you should be looking for. Most importantly, the certificate should provide a statement of traceability to the appropriate national standards.

In addition, specific information pertaining to the instrument and the calibration must be detailed in the certificate. Appendix D of HB86.1 1996 provides a list of what calibration certificates should contain.

It must be remembered, however, that the calibration certificate contains much more than just performance, traceability and compliance data - it contains the accumulated technical knowledge and skill of the provider, and if it is a NATA endorsed certificate, an independent affirmation of that expertise.

The ISO/IEC 17025 factor

As already mentioned, the proper calibration of critical equipment is so crucial to a company's service and reputation that industry cannot afford to rely simply on assurances by the service provider that they know what they're doing.

Globally, calibration expertise is independently evaluated and affirmed when a calibration agency undergoes third-party accreditation to the international standard, ISO/IEC 17025.

In this country, not all calibration agencies have NATA accreditation to ISO/IEC 17025. Some have ISO 9000 certification, and many have no independent credentials at all.

Some have been operating for many years, but this does not necessarily mean they are doing things consistently, correctly or in accordance with the relevant standard.

Any external evaluation of a calibration provider must address both the technical competence of the service (knowledge, skill, performance and competence of the service personnel, etc) and also the systems or management side of the business (compliance with good management practices, record keeping, training, supervision, etc).

Without both sides being covered, confidence in that provider cannot be effectively established or demonstrated.

ISO 9000 certification effectively addresses the management side of the business, but it is not designed to address the issues of technical competence. The evaluation of technical competency requires the use of independent specialist technical assessors, who are able to observe performance and make value judgements on the competence of the service personnel.

Accreditation to ISO/IEC 17025 covers both sides, management and technical competence, through the use of specialist peer evaluators, who are themselves calibration experts rather than generalist auditors.

The ISO/IEC 17025 assessment focuses on establishing the knowledge and skill of the service personnel and the overall technical capabilities of the agency, in addition to ISO 9000 management elements.

The peak Australian/New Zealand accreditor of ISO 9000 certification bodies, JAS-ANZ*, itself recognises this crucial difference in its policy for ISO 9000 audits.

It specifies that calibration certificates presented by ISO 9000 certified companies in Australia and New Zealand must indicate that the calibrations for critical equipment have been performed by an accredited calibration service, or by the primary calibration institutes in the two countries.

By doing so, JAS-ANZ recognises that for critical, traceable calibrations, ISO 9000 certification of the calibration service isn't enough.

This use of accredited calibration agencies is also supported by the other key members of the Australian Measurement, Standards and Conformance Infrastructure.

Dr Barry Inglis, director of CSIRO's National Measurement Laboratory, which is the peak body for measurement traceability and calibration in Australia, explains that "Accredited calibration laboratories form a critical part of the national measurement system. The accreditation process provides the basis for confidence in a calibration service, addressing, as it does, staff competence, measurement traceability, methodology and laboratory environment".

Dr Judith Bennett, executive director of the National Standards Commission provides a similar view:

"The National Standards Commission, which is responsible for the coordination of the national measurement system, requires that all organisations responsible for pattern approval testing, verification and calibration of trade measuring instruments be accredited by NATA to ISO/IEC 17025".

JAS-ANZ - Joint Accreditation System of Australia and New Zealand