Topic: Conformance Decision Rules to Support ISO/IEC 17025 Under Revision
Speaker: Jon Harben, Keysight Technologies
Topic: The Challenges of Large Scale Materials Testing
Speaker: Raymond Churchwell, The Boeing Co.
Abstract: Large scale material testing has become increasingly important as aircraft continue to increase in seating capacity and fly at higher gross weights. Boeing made a strategic decision in 2013 to install a 3.5 million pound test frame to support aircraft development, supplying the certified data necessary to expand design manuals, and support obtaining FAA certification. This presentation covers the installation of the test frame, calibration of the frame and the various types of instrumentation used during fatigue and static failure testing.
Topic: Acoustic Energy Based Non-Melt Fusion Additive Manufacturing of Solid Metals
Speaker: Keng Hsu, Arizona State University
Abstract: Current commercial melt-fusion based metal 3D printing technologies face several drawbacks which limits the process and material flexibilities. The same limitations also increasingly pose health and safety concerns. A novel process, Directed Metal Filament Deposition (DMFD), is introduced that overcomes these drawbacks. The DMFD process uses the softening effect in metals when acoustic energy is concentrated at material lattice imperfections to allow voxel shaping at low stresses. Coupled with the acoustic vibration-enhanced inter-diffusion of materials across internal interfaces, metallurgical joints are formed at filament-substrate and filament-filament interfaces. As compared with thermal energy employed by melt-fusion techniques, acoustic energy used in DMFD is several orders of magnitude more efficient in coupling into metal lattices to cause materials shaping and bonding. Using the proposed process, 3D objects are built and the process is demonstrated under ambient conditions. In this talk, the process, alone with its key characteristics are presented.
Topic: Improvements Of The Dynamic Gravimetric Flow Standard (Dgfs) Below 0.2 Mg·S–1 N2 (10 Sccm)
Speaker: Casey Rombouts, Fluke Inc.
Abstract: In 2011, Laboratoire National de Métrologie et d'Essais (LNE) installed a primary gas flow standard (dGFS) based on the dynamic gravimetric method. The dGFS developed by Fluke Calibration-Phoenix (FCP) was initially designed to calibrate molbloc laminar flow elements in the range from 0.2 mg·s–1 to 200 mg·s–1 of nitrogen (10 sccm to 10 slm) with a manufacturers expanded uncertainty (k = 2) on the order of ±0.06% of reading (variant with mass depleted). An LNE uncertainty analysis of the dGFS components using the GUM approach has given an expanded uncertainty (k = 2) on the reference mass flowrate of ± (0.06 % of reading + 3×10-4 mg·s–1) in this flow range. This uncertainty has been validated through different international comparisons using commercial transfer standards such as molbloc LFE’s or portable volumetric devices.
LNE and FCP use the dGFS outside the working range to measure flows below 0.2 mg·s–1. The system as delivered has issues with accurate and repeatable leak determinations and stable measurements in this lower flow range leading to results that are not as satisfactory and with higher uncertainties.
This paper presents the work being done to significantly reduce or reliably quantify the dGFS leakage and to measure stable and repeatable flows between 0.02 mg·s–1 and 0.2 mg·s–1 of nitrogen (1 sccm to 10 sccm) with an associated uncertainty never achieved with the dynamic gravimetric method.
An international low flow key comparison is in the early stages of development with NIST (USA), CMS (Taiwan), INRIM (Italy) and LNE (France), where improvements in the dynamic gravimetric method would be valuable to LNEs collection of data and the overall comparison.
Topic: Using Microsoft Excel as a Monte Carlo Simulation Tool for Estimating Measurement Uncertainties
Speaker: Hy D. Tran, PhD, PE Sandia National Laboratories
Abstract: Estimating measurement uncertainty is a critical task in any measurements—whether the measurement is performed to support a calibration, or whether the measurement is used in validation or verification of performance, or whether it is used to support scientific advances. The ISO “Guide to the Expression of Uncertainty in Measurement” (commonly known as the GUM) is accepted as a framework for how to estimate uncertainty—but using the GUM can be complex. Supplements to the GUM have been published, which describe the use of a numerical method, namely the use of Monte Carlo methods, in estimating measurement uncertainty. This tutorial will demonstrate Monte Carlo methods; the use of MS-Excel in a Monte Carlo simulation, and a case study in using MS-Excel in estimating measurement uncertainty where there are correlations in the individual components of uncertainty. The attendee is encouraged to bring a laptop computer that has MS-Excel 2010, to participate in the demonstrations and case study.
- The attendee will be able to explain what a Monte Carlo simulation is, and some of the requirements for a successful Monte Carlo simulation.
- The attendee will know how to generate pseudo-random numbers with different probability density functions in MS-Excel.
- The attendee will be able to perform a simple estimation of measurement uncertainty (for a narrowly defined problem) using Monte Carlo methods.
The current draft of ISO/IEC 17025 contains a clause to “document the decision rules employed taking into account the level of risk (such as false accept and false reject and statistical assumptions) associated with the decision rule employed . . . when a statement of conformity to a specification . . . is requested” (7.7.1). This paper presents the false-accept risk and corresponding false-reject risk for four decision rules compliant with JCGM 106:2012 
. We provide simple equations to limit risk to pre-determined amounts. Several case studies illustrate when to use “Specific” or “Global” risk. When “Global” risk is appropriate, the decision rules can be applied with limited knowledge of a priori probability.