This page belongs to: National Measurement Institute

Pattern approval instrument testing and assessment

The National Measurement Institute (NMI) assesses your submitted pattern to ensure it meets relevant requirements.

Apply for pattern approval

Pattern approval and other testing services

Measuring instruments used for trade in Australia must be pattern approved. Learn about pattern approval and how to apply.

Initial assessment

We do an initial assessment to:

  • make sure you have supplied all the relevant information
  • determine testing requirements.

We may able to visit you on site to inspect large instruments.

After the initial assessment, we provide an outline of the testing needed. We will also give a cost estimate if required. Learn more about pattern approval fees.

You may also need to:

  • provide any extra information we’ve requested
  • make any necessary instrument modifications we’ve requested.

Full assessment

Once we receive the requested extra information and you have made any modifications to the equipment, we can conduct a full assessment of your pattern.

When we examine instruments for pattern approval, we assess:

  • your instrument’s documentation
  • how your instrument operates against the pattern approval requirements 
  • the results of your instrument’s performance testing.

Performance testing

Performance testing ensures your instrument:

  • is accurate, reliable and functions as designed
  • can continue to meet allowable maximum permissible errors when subjected to a range of conditions designed to replicate conditions in the field.

We base our performance tests on the specifications detailed in the pattern approval requirements.

We conduct:

  • temperature testing
  • damp heat, steady-state and cyclic humidity testing
  • AC and DC power variation testing
  • immunity to radiated interference testing
  • immunity to conducted radio-frequency field strengths testing
  • electrostatic discharge testing
  • line-borne interference testing.

We will contact you with the results of each test after we perform them.

Acceptance of test results

We accept test results from other ISO 17025 accredited facilities with appropriate scope of accreditation. We generally do not accept manufacturer’s test results.

To help us to determine acceptability, you can provide:

  • full detailed test reports, including test results
  • details of the laboratory that conducted the test including its ISO 17025 certificate of accreditation, if they are not part of a formal mutual acceptance agreement.

We have mutual acceptance agreements with:

Approving authorities                              

We may appoint approving authorities to test measuring instruments.

Find an approving authority to test your measuring instrument for pattern approval.

Decision to issue a certificate of approval

After we have assessed your instrument pattern and documentation, we make a decision. If we approve your instrument, then we issue a certificate of approval.

Non-passing instruments

We will notify you if your instrument does not comply with a requirement or specific test. You will be able to make modifications and resubmit your instrument.

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