The Problem of Uncertainty
A calibration lab’s uncertainty budget is the main indicator of the quality of calibrations performed by the lab. Needless to say getting your uncertainty budget right will drastically improve the quality and efficiency of your operations.
However, maintaining uncertainty budgets is a problematic and costly proposition; particularly when higher quality standards require the lab to customize its uncertainty budgets for every test point on every calibration.
While various spreadsheets and special packages will facilitate uncertainty budgeting and reduce the calculation burden. These solutions typically represent an entire measurement area, for example DC voltage or pressure, with a single simplified budget to support the accredited scope. However, reference and measured values, input and influence quantity values, measurement processes, and Unit Under Test effects, all vary in practice, therefore the as-measured and as-documented uncertainties always differ. Without an effective way to validate the actual work done, test point by test point, calibration quality suffers. Either your example budget conservatively inflates your uncertainties (costing you market share and requiring more expensive equipment), or your work goes to the customer with higher uncertainties, lower test-uncertainty ratios, and higher false-accept risk than you reported or documented (incurring rework, audit findings and customer dissatisfaction). Test and calibration labs strike a balance between quality and support cost determined by their available technology. Without an all-in-one methodology, this balance tilts toward a lose-lose quality-cost compromise.
An ideal technological solution would encapsulate uncertainty software and integrate it such that labs get the best of both worlds: easy maintenance (low cost) and fully automated quality validations and accurate certificates.
Meet the MOX Metrology Process Studio (MPS)
MPS is a state-of-the art application for calibration of measurement and test equipment which combines high-power quality controls, measurement analyses, quality metrics, and process automation in an integrated laboratory management solution.
The MOX Philosophy
MOX brings a win-win integrated management solution to your calibration lab. No manual calculations, no redundant entries, no copying from one system to another, no painful uncertainty propagation when changes arise, no conflicting tolerances from system to system. Instead, you get as-designed and as-measured uncertainty budgets by test point at your fingertips. MOX technology creates a new paradigm that shifts the cost-quality trade-off to a whole new performance region.
A little bit about how MOX MPS works
MPS encapsulates measurement procedures in data-sheet templates that execute in manual or fully automated mode. The powerful MPS automation engine communicates with instruments via IEEE 488 (GPIB), USB, ethernet and RS 232 and automatically performs calibrations.
Powerful, intuitive tools and wizards allow users to easily design and develop data sheets according to equipment specifications and calibration requirements with instructions and graphic aids to assist the technician during calibration.
A unique feature of MPS is that measurement data captured during calibration include not only measured and reference values, but also the applicable uncertainty model and risk information. This allows MPS to automate many metrology engineering tasks, such as guard banding, calculating uncertainty (EMU) and test ratios (TARs and TURs) using specifications and other parameters from a test instrument’s set point, the standards used and the measurement system configuration. The powerful and highly automated MPS uncertainty modeling system allows you to manage the uncertainty budget automatically or add your own budget items and repeatability analysis. MPS also manages automatic standard substitution in uncertainty models; so if a default standard becomes unavailable, the user can simply select an alternative standard, and MPS will automatically replace the uncertainty model budget item applicable to the substituted standard and recalculate the uncertainty.
Other advanced uncertainty modeling features include calculating uncertainty from entered error limits and selected distributions, entering, storing, and using repeatability analysis data, and handling multiple correlated test-point equations.
Other Impressive Features
The built-in analysis system allows users to view calibration history and perform critical analyses. This feature simplifies and speeds common engineering tasks. The history view lets an engineer quickly gage instrument tolerances against actual performance data.
Test-point-level reverse traceability quickly identifies any impacts from out-of-tolerance measurement standards.
The database statistics miner performs NCSLI RP-1-compliant interval and reliability analysis, and generates summary reports.
MPS also communicates with COM (component object model) server applications, so you may incorporate your own custom plug-ins or other applications such as Microsoft Excel into your MPS calibrations.
MPS fully complies with 21 CFR Part 11 and includes an audit log system that records and reports all critical and configuration-management transactions such as document versions and approvals. Its features easily support ISO/IEC 17025 and ANSI/NCSLI Z540.3 compliance. MPS fully integrates with the MOX Calibration Management System, but you may use it alone or in conjunction with your ERP or laboratory management system.