Ensuring precision with round robin tests
National Metrology Institutes (NMIs) are at the top of the the pyramid for precision and accuracy in measurement standards of every country. As the leading authority for calibration standards, NMIs define the quantities and processes essential for high-precision measurements on a national level. They develop and maintain calibration procedures and also serve as high-level partners for science, industry, and commerce - ensuring that all sectors can rely on accurate and traceable measurements.
This importance can be illustrated using a so-called calibration pyramid that visualizes traceability and hierarchy. The NIM stands on top, followed by accredited calibration laboratories and so on, each level lower meaning higher measurement uncertainty and lower accuracy.
Quality assurance with critical requirements
To guarantee the quality of their measurement equipment and procedures, NMIs collaborate on a global level by participating in interlaboratory comparisons. These so-called round robin tests are sometimes carried out with the participation of an industrial partner.
At SPEKTRA, we understand the ambitious requirements involved in interlaboratory comparisons when several laboratories are involved. These can be a comparison of measurement results for the same device under test, a validation of calibration processes or other tasks.
What is your main advantage in working with an industry partner like SPEKTRA?
- Extensive network of laboratories: We connect a vast network of laboratories and metrology experts, fostering collaboration and sharing best practices.
- High-quality systems and components: We conduct tests on our in-house, state-of-the-art systems, high-quality exciters and components, ensuring precise and reliable calibration results.
- Compliance with standard norms: Our round robin tests help laboratories meet the stringent requirements of ISO 17025:2018 (which includes prerequisites for the qualification of testing and calibration laboratories), proving their competence and reliability.
How does a round robin test work?
A round robin test of measuring equipment in metrology laboratories is used to check measurement accuracy in calibration. A standardized test object is measured successively by several laboratories. The results are collected and statistically analyzed to evaluate the deviations and measurement uncertainties. This ensures that all participating laboratories perform consistent and accurate measurements.
Round robin tests help ensure the quality and traceability of measurements and to identify differences between laboratories. They are also known as "interlaboratory comparison" or "proficiency testing".
Why is it crucial to participate in round robin tests?
- Enhanced quality assurance: Regular participation in interlaboratory comparisons ensures that the quality of calibration processes and measurements is consistently high.
- Reduce measurement uncertainty: Interlaboratory comparisons provide reliable means to verify the measurement uncertainty generated with various procedures. This helps ensure results with the highest accuracy/lowest measurement uncertainty.
- Calibration process comparison: Laboratories can compare their calibration processes with others, identifying areas for improvement and standardizing practices.
- Compliance and competence: Fulfilling ISO 17025:2018 requirements through these tests demonstrates the laboratory’s competence to customers, superiors, and regulatory authorities.
- Access to expertise: Being part of a large network of laboratories and metrology experts allows for knowledge exchange and continuous improvements.
Did you know that...
... measurements do not provide absolutely accurate values?
The measurement result always depends on the measurement method and equipment used, the environmental conditions, and the competence of the calibration technician. To make the results truly comparable, each measurement must be accompanied by an indication of the measurement uncertainty.
Two elements of data are required to assess measurement uncertainty:
- the range within which the true value of the measurand is expected and
- what is known as a confidence level which indicates how reliable the actual value is within that range.
The value of measurement uncertainty therefore helps increase confidence in the measurement results.
Accreditation according to DIN EN ISO 17025:2018-03 ensures that the measurement results shown on the calibration certificates are standardized and therefore comparable.
SPEKTRA experts are active members of several national and international standards committees and participate in the research and development of new measurement technology. We also regularly publish articles and present them at specialist conferences.
Some of our latest findings will be presented in Hamburg, Germany at the IMEKO World Congress in August 2024. In line with the topic of the congress “Think Metrology”, the SPEKTRA experts are presenting three papers:
- Primary calibration on shock exciter SE-201
- Primary calibration of seismic sensors down to 8 mHz – challenges regarding the straightness of shaker bearings
- Calibration of digital DUTs, like inertial navigation systems
Conclusion
Round robin tests can be used to maintain the highest standards of calibration excellence for NMIs and calibration laboratories. With the help of our extensive network and high-quality systems, these institutions can ensure quality, verify measurement uncertainty, compare calibration processes, and fulfill ISO 17025:2018 requirements effectively.
If your organization faces similar challenges, contact our experts today to learn more about round robin tests!
Phone: +49 351 400 24 0 | Email: sales@spektra-dresden.com
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