Automation has revolutionized testing laboratories around the world, resulting in increased efficiency, repeatability, and overall quality. From tensile and heat distortion tests performed by materials laboratories to radio frequency (RF) and over the-air (OTA) tests performed by electromagnetic compatibility (EMC) laboratories, the shift toward automation is clear and accelerating. However, despite the many benefits of automation, there are unique challenges that we should be aware of, particularly in the context of ISO/IEC 17025 and other conformity assessment schemes. To fully benefit from automation while maintaining compliance and quality, it is critical that laboratories reassess traditional notions of competence, equipment validation, and data monitoring.
Automation In Practice
Materials Testing
In the materials testing world, automated test systems have vastly improved repeatability and efficiency for tests like tensile strength, Differential Scanning Calorimetry (DSC), and Heat Distortion Temperature (HDT). Robotic arms now load samples with identical force and alignment. Software systems perform complex calculations instantly, replacing manual measurements that once required rulers, graph paper, and hours of time
For example, HDT testing no longer requires an operator to monitor temperature changes manually; the system now captures and records the transition point automatically. In DSC, where entire days were once spent analyzing thermal graphs, results are now generated and interpreted within minutes.
RF and EMC Testing
Perhaps no area within the Electromagnetic Compatibility (EMC) field of testing has seen more change in the past several years than RF/Radio testing. Tests that used to be performed manually – such as Transmit Power, Power Density, and Bandwidth – are now highly automated.
Today, these processes are streamlined. Devices under test (e.g., Bluetooth modules, radios, access points) are connected through RF switch boxes to spectrum analyzers, all of which are controlled by software. From a software interface, the user simply checks the boxes of the appropriate tests and channel and clicks “RUN.” What used to take an entire day may now be completed in just 30 minutes.
Opportunities And Risks
The benefits of automation are obvious:
- Repeatability and Accuracy: Automated systems reduce human variability and improve repeatability and accuracy.
- Efficiency: Complex tests and calculations are completed faster, allowing for greater output.
- Quality: Automated systems greatly improve the quality of testing through limited human error and standardized operation.
However, increased automation and reliance on test equipment software brings unique challenges and risks that laboratories should be aware of, especially when implementing requirements of ISO/IEC 17025.
Applying ISO/IEC 17025 To Automated Test Processes
Personnel Competence – Clause 6.2.3
In highly automated systems, laboratory personnel often learn how to run the software and not the equipment, raising questions related to competency and nonconforming work.
ISO/IEC 17025 6.2.3 requires that personnel must not only be competent to perform their assigned activities but also able to evaluate the significance of deviations.
What happens when a test fails? Can an EMC technician be considered competent if they don’t understand how to configure a spectrum analyzer, or the function of settings like resolution bandwidth, video bandwidth, attenuation, and sweep speed? What if they can’t recognize when the equipment is overloaded or saturated?
ISO/IEC 17025 doesn’t require the operator to be an expert, but someone in the lab must be – and the lab must have a procedure to ensure deviations are correctly identified, evaluated, and responded to appropriately.
Intermediate Checks – Clauses 6.4.10
Like any other testing equipment, automated systems too must be regularly checked to confirm they are functioning properly and achieving accurate and reliable results. ISO/IEC 17025 6.4.10 requires intermediate checks when necessary to maintain confidence in the performance of the testing equipment. The laboratory must maintain a procedure for how they intend to perform these checks. However, the frequency and nature of these checks may be determined by the laboratory. When developing a procedure for intermediate checks, it is important to understand the intent of this process: to verify that equipment is functioning properly and achieving accurate test results between calibration cycles. For highly automated systems where the laboratory is putting a high degree of trust in its equipment, the importance of intermediate checks is critical, and should be considered when developing a plan or procedure.
Ensuring the Validity of Results – 7.7.1
While ISO/IEC 17025 6.4.10 is meant to ensure confidence in the laboratory’s testing equipment, 7.7.1 examines the entire test system, including equipment, personnel, and reporting mechanisms. Like 6.4.10, it is up to the laboratory to determine how these checks are performed, but the resulting data must always be recorded in such a way that trends are detectable.
In EMC laboratories, this requirement poses a challenge for automated RF test systems that have self-check or loop-back functions that compensate for cable loss and other associated loss of any filters, RF switches, etc. Typically, these checks do not produce any data that could be used to establish such a trend, as required by 7.7.1.
In these instances, laboratories may choose to perform periodic checks of the cable loss between the device and the system input. While this may be technically sufficient to meet the clause — especially if records are kept — it arguably falls short of the essence of the requirement.
Nuances between test systems such as the one described above should be considered when developing procedures in accordance with 7.7.1. While this clause lays out various possibilities (a – k) for how a laboratory might ensure the validity of results, the laboratory should develop their procedure using a risk-based approach, taking into consideration what is value-added for their system, and not simply what satisfies an auditor or “checks a box.”
Software Validation – Clause 7.11
Another important area to be considered when implementing automated test systems is software validation. While equipment software supplied by the manufacturer is often assumed to be validated, laboratories must confirm that the software performs according to their specific needs.
Take, for example, tensile testing for plastics according to ASTM versus ISO test methods. ASTM D638 requires a secant modulus when calculating a material’s elasticity while ISO 527 requires a chord modulus. If the laboratory is performing a tensile test according to ISO 527 but the equipment software is calculating a secant modulus, the laboratory has not met the requirements of the test method. It is important for the laboratory to not only understand these unique variations between test methods but to ensure that the software employed by the laboratory meets the necessary requirements of each.
Conclusion
Automation is undoubtedly reshaping testing laboratories across all fields and industries, bringing greater efficiency – and unique challenges – to organizations. As technologies advance and automated processes continue to become more widespread, it is critical to understand their relationships to ISO/IEC 17025 and other conformity assessment standards in order to maintain quality and harness the full benefit of test process automation.
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