Inter-Laboratory Comparison Study Using Modular Instrumentation and Lesson Learned

An inter-laboratory comparison (ILC) is a key criterion for laboratory accreditation. The ILC process is also an important asset in reliability, measurement assurance, and staff confidence. ILCs are conducted to evaluate reference standards, calibration process, a measurement method, or a combination of these elements. The use of new and emerging technologies in the metrology laboratories is also impacted by ILCs. This paper studies the use of Modular Instrument as standards in an ILC, providing insight into process to establish confidence in their performance in a measurement environment. Modular Instruments have shown strong growth, taking market share in the core of many automated applications. Due a variety of factors, there is growing evidence suggesting that the industry is transitioning into a new phase, an unsettling shift where open system modular architectures become the mainstream choice for automated test. In many applications users have a choice between deploying modular instruments, traditional instruments, or combination of the two. In this context, modular instruments are largely a substitution for their traditional counterparts. Calibrating the measurement components of a modular instrument is just an important as calibration of traditional instruments. Introducing modular instrumentation in the metrology and laboratory accreditation process means that comparisons are needed to demonstrate performance and competence in performing regular measurement services. National Instruments piloted an ILC using modular instrumentation with the goal of evaluating the comparability of the results and the competence of making measurements between the several laboratories. To ensure appropriate of measurement evaluation occurred, results included the verification of the reported measurement uncertainties. During the process valuable lessons were learned for conducting this study. These have included identification of systematic offsets and additional sources of variation in the process. This paper reviews the comparison to date, drawing conclusions from the findings and making proposals for future inter-comparison using Modular Instrumentation.