Round Robin Test Research Articles

Challenges in tuning the measurement performance of a reverberation chamber

Round-robin testing determined that a high degree of reproducibility exists between laboratories that conduct sound absorption measurements in accordance with ASTM C423. Factors that include room dimension, source location and diffuser type have been identified as sources for differences in measurement results. Such lab to lab testing variation presents a challenge when reverberation chambers are replaced with new design and construction features that are not identical. An iterative process is required to produce measurements that match historical results. The presentation will describe the design approach utilized to construct a new reverberation room with different dimensions, diffuser types and materials. Experimental data will be presented showing the results of modifications made to the chamber after achieving initial qualification metrics. The iterative process provided an opportunity to study the impact of diffuser type and surface area and other properties on reducing the performance gap between the two reverberation rooms.

Tyre/road noise measurements on ISO tracks according to the UNECE Regulation 117

Within the Polish-Norwegian research project ELANORE, a limited Round Robin Test has been performed on 3 ISO tracks in Northern Europe. The basic objective of the project is to improve the EU directive on labelling of tyres for noise and rolling resistance. This directive is based on the measurement procedures proscribed in the UNECE Reg.117. On all test tracks the same car, test tyres and test equipment as well as personnel were used to minimize the measurement uncertainties. All tracks were built according to the specifications of ISO 10844:2014. Five sets of C1 test tyres were used which consisted of two summer tyres, one all-season, one winter and one set of the SRTT tyres. Except for the SRTT tyres, the other 4 had labelled noise values from 67 to 74 dB. In addition to the test conditions specified in Reg.117, a modified test was also included, where the load and inflation pressure were adjusted to better fit the test vehicle specification. Due to some adverse weather conditions at two of the test tracks, only a part of the test program was accomplished. The paper will present preliminary results from these measurements. A follow-up tests are planned for 2022.

Medikationsanalysen in öffentlichen Apotheken: Konzept zur externen Qualitätsüberprüfung

BackgroundA medication review aims at the optimization of medication use, the detection of drug-related problems (DRPs) and the recommendation of interventions. As part of the pilot project “Arzneimittelinitiative Sachsen-Thüringen” (ARMIN) and caused by the introduction of several training programs, numerous public pharmacies in Germany currently offer medication reviews for patients. However, a standardized method for external quality control has so far not been established. MethodsA round robin test for medication reviews was designed in written form by five pharmacists with expertise in different areas (Drug information service ARMIN, Saxonian Chamber of pharmacists, public pharmacy, hospital pharmacy), based on the recommendations of the guideline for medication reviews of the German Federal Chamber of Pharmacists (Bundesapothekerkammer). On the basis of a fictitious case study the participants were asked to check a patient's medication data for the presence of DRPs, propose possible solutions and generate a medication plan. The solutions were assessed by two pharmacists of the drug information service ARMIN on the basis of a best practice solution that had been consented in the study group beforehand. Results102 pharmacists and 13 pharmacy students in internship took part in the round robin test. On average, participants achieved a score of 7,62 out of 9 for recognizing DRPs and recommending solutions and a score of 0,79 out of 1 for generating a correct medication plan. 106 participants (92%) met the requirements for successful participation (recognizing the three most relevant DRPs and at least one further DRP as well as generating an adequate medication plan). The implementation of the approach described here proved to be practicable The State Directorate of Saxony accepted the round robin test as a measure for external quality assessment in accordance with legal requirements. ConclusionsDue to the nationwide introduction of medication reviews as a pharmaceutical service in June 2022, medication reviews performed by German community pharmacies will gain in importance in the coming years. This is why quality assurance is necessary. Since the participants‘ performance in medication analysis becomes comparable by completing the round robin test, this instrument appears to be potentially suitable for the external quality assessment of medications reviews nationwide.

First proficiency testing for NGS-based and combined NGS- and FISH-based detection of FGFR2 fusions in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma harbours druggable genetic lesions including FGFR2 gene fusions. Reliable and accurate detection of these fusions is becoming a critical component of the molecular work-up, but real-world data on the performance of fluorescence in situ hybridisation (FISH) and targeted RNA-based next-generation sequencing (NGS) are very limited. Bridging this gap, we report results of the first round robin test for FGFR2 fusions in cholangiocarcinoma and contextualise test data with genomic architecture. A cohort of 10 cholangiocarcinoma (4 fusion positive and 6 fusion negative) was tested by the Institute of Pathology, University Hospital Heidelberg, Germany. Data were validated by four academic pathology departments in Germany. Fusion-positive cases comprised FGFR2::BICC1, FGFR2::DBP, FGFR2::TRIM8, and FGFR2::ATE1 fusions. In a second step, a round robin test involving 21 academic and non-academic centres testing with RNA-based NGS approaches was carried out; five participants performed FISH testing in addition. Thirteen of 16 (81%) centres successfully passed the NGS only and 3 of 5 (60%) centres passed the combined NGS + FISH round robin test. Identified obstacles were bioinformatic pipelines not optimised for the detection of FGFR2 fusions and assays not capable of detecting unknown fusion partners. This study shows the benefit of targeted RNA-NGS for the detection of FGFR2 gene fusions. Due to the marked heterogeneity of the genomic architecture of these fusions, fusion partner agnostic (i.e. open) methodological approaches that are capable of identifying yet unknown fusion partners are superior. Furthermore, we highlight pitfalls in subsequent bioinformatic analysis and limitations of FISH-based tests.

International round robin test of environmentally benign lubricants for cold forging

The use of lubricants without conversion layers is a global target of the cold forging industry. Compared to conventional lubricant systems based on zinc phosphate coatings, these fluctuate more in their tribological properties. In a worldwide round robin test, thirteen different lubricants were compared in tests with six different tribometers. The results show significant differences in friction coefficients both between different lubricants and between tribometers. A multiple regression model describing the dependence of the coefficient of friction on tribological loads allows for a consistent merging of the data. The model is successfully validated by a full-forward extrusion process.

Metrological generation of SI-traceable gas-phase standards and reference materials for (semi-) volatile organic compounds

EN 16516 sets specifications for the determination of emissions into indoor air from construction products. Reliable, accurate and International System of Unit (SI)-traceable measurement results of the emissions are the key to consumer protection. Such measurement results can be obtained by using metrologically traceable reference materials. Gas-phase standards of volatile organic compounds (VOCs) in air can be prepared by a variety of dynamic methods according to the ISO 6145 series. However, these methods are not always applicable for semi-VOCs (SVOCs) due to their high boiling point and low vapour pressure. Therefore, a novel dynamic gas mixture generation system has been developed. With this system gas-phase standards with trace level VOCs and SVOCs in air can be prepared between 10 nmol mol−1 and 1000 nmol mol−1. The VOCs and SVOCs in this study have normal boiling points ranging from 146 °C to 343 °C. Metrologically traceable reference materials of the gas-phase standard were obtained by sampling of the VOC gas-phase standard into Tenax TA® sorbent material in SilcoNert® coated stainless steel tubes. Accurately known masses between 10 ng and 1000 ng per VOC were sampled. These reference materials were used to validate the dynamic system. Furthermore, the storage and stability periods of the VOCs in the reference materials were determined as these are crucial characteristics to obtain accurate and SI-traceable reference materials. In a round robin test (RRT), the reference materials were used with the aim of demonstrating the feasibility of providing SI-traceable standard reference values for SVOCs for interlaboratory comparison purposes. Based on the results from the validation, the storage and stability studies and the RRT, gas-phase standards and reference materials of VOCs and SVOCs with relative expanded uncertainties between 5% and 12% (k = 2) have been developed. These reference standards can be used as calibrants, reference materials or quality control materials for the analysis of VOC emissions.

Establishment of the standard method of magnetostriction measurement of grain-oriented electrical steel strip and sheet

Standard method of magnetostriction measurement of grain-oriented electrical steel strip and sheet by means of a single sheet tester and an optical sensor was established as IEC 60404-17 Ed.1 [1] by the IEC/TC68 after intense considerations among magnetostriction experts. A new idea called “bridge” was introduced in order to minimize effects due to mechanical factors and other improvements were made. The 4th international round robin test (RRT) was carried out in 2020 and it was confirmed that the measurement reproducibility of the peak-to-peak value of magnetostriction improved from 5% or less in the 3rd RRT to 2% or less.

1st international round robin test on safety characteristics of hybrid mixtures

There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another.In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes.

Experimental verification of indirect tests for stress-crack opening curve of concrete in tension from a round robin test: application to railway sleeper elements

This paper presents experimental verification of indirect tests for the determination of the stress-crack opening curve of concrete, based on the method described in the RILEM TC 187-SOC report and submitted to ACI Committee 446 for Fracture Toughness Testing of Concrete, which relies on the standard cohesive model. In such method, a bilinear approximation of the softening curve is determined from three-point bending tests of notched specimens under crack-mouth-opening-displacement control and from tensile splitting tests, which produces good predictions of the complete crack evolution. The current work focusses on the brittleness length, which is directly related to the parameters of the linear curve defined by the first branch of the bilinear curve, and is one of the main fracture parameters of concrete, since it controls the behaviour of thin cracks. This length can be obtained from a simple version of experiments conducted up to peak load, thus, favouring its application in the industry. In particular, this work presents the results of a round-robin test carried out in collaboration with the Spanish Association of Railway Sleeper Element Manufacturers to determine the brittleness length of concrete. A specific implementation of the method has been proposed in order to perform the tests by using the facilities available in all the factories. The results of the round-robin test have been satisfactory, thus, supporting the viability of the RILEM and ACI proposals. Moreover, a method has been developed which allows the brittleness length of concrete to be determined easily in railway sleeper element factories.

Reproducibility and Scattering in Additive Manufacturing: Results from a Round Robin on PBF-LB/M AlSi10Mg Alloy

Abstract The round robin test investigated the reliability users can expect for AlSi10Mg additive manufactured specimens by laser powder bed fusion through examining powder quality, process parameter, microstructure defects, strength and fatigue. Besides for one outlier, expected static material properties could be found. Optical microstructure inspection was beneficial to determine true porosity and porosity types to explain the occurring scatter in properties. Fractographic analyses reveal that the fatigue crack propagation starts at the rough as-built surface for all specimens. Statistical analysis of the scatter in fatigue using statistical derived safety factors concludes that at a stress of 36.87 MPa the fatigue limit of 107 cycles could be reached for all specimen with a survival probability of 99.999 %.

Optimisation of the uncertainty of oil spill identification from replicate comparative analyses: Comparison of standardised and novel identification methods

Oil spill identifications involve the comparison of oil fingerprints between the oil spill and suspected oil sources, defined by ratios between the abundances of oil-discriminating compounds, Diagnostic Ratios (DR). The normalised Nordtest and EN 15522-2 methodologies use Student's t statistic (S-t) or a maximum relative difference (SC) to compare mean DR from replicate sample analysis. While the S-t method assumes the normality of DR distribution, the SC method is based on controlled DR dispersion. However, when false, the assumptions and approximations adopted can lead to low true identification rates. This work presents a novel computational tool for the statistically sound oil spill identification that allows following requirements defined by EN 15522–2, the comparison of replicate DR determinations, and the use of different DR sets and formats. The tool uses the Monte Carlo Method (MCM) to describe the probability distribution of the difference of mean DR, allowing estimating the probability of the true acceptance of fingerprints equivalence. The studied methods were applied to the comparison of signals from the same oil and to a real scenario reproduced in an International Round Robin Test. The methods were compared considering the probabilities of true acceptance of oil patterns equivalence based on a single, γ, or various, δ, DR. The MCM method performs identifications with γ equivalent to the defined confidence level for the comparison, P. Since the various DR studied are not perfectly correlated, the δ is below P. The number of replicate analyses performed and the DR considered in the comparison affect identification performance. The S-t produces comparison criteria with a γ lower than P. The SC criteria for duplicate analysis is associated with a δ lower than the obtained by the MCM. A user-friendly MS-Excel spreadsheet is available to perform oil pattern comparisons using various methods and conditions.

Method to detect carbon in silicon crystals in the concentration range down to 5 × 1014 cm−3 by Fourier transform infrared absorption at room temperature

The procedure of Fourier transform infrared absorption (FT-IR) at room temperature for quantifying C impurities in Si crystals was reexamined to improve the detection limit down to 5 × 1014 cm−3. Since the substitutional C absorption peak overlaps with a strong two-phonon absorption, the difference spectroscopy is necessary with using a C-lean reference sample. A baseline flatness of less than 0.0005 in absorbance and a thickness uniformity of less than 0.001 mm are required to realize a detection limit of 5 × 1014 cm−3 for 2 mm thick samples. To check the flatness, we define the Si/Si baseline which is the difference in the absorbance spectra measured twice with the removal and attachment of the same Si sample. Four organizations participated in the FT-IR round-robin test for ten samples with the C concentration ranging from 3.6 × 1014 to 3.3 × 1015 cm−3. The obtained C concentrations were almost within 30% deviation from the values determined by reliable secondary ion mass spectroscopy.

Progress on developing a new SAE damping standard for the ground vehicle industry

With the emphasis in lightweighting of vehicle body structures, body panel vibration and structure-borne noise are big concerns to sound package engineers. Damping materials are used to mitigate these issues. As aluminum and different composite materials are used to make lightweight vehicle body panels, a damped panel using these materials cannot be used in Oberst bar damping tests which uses a non-contacting transducer. To address this situation, SAE's Acoustical Materials Committee is developing a new damping standard (SAE J3130) based on the mechanical impedance measurement method, also called the CenterPoint method. The committee is currently conducting a round robin study that includes different types of damping materials and different types of vibrating bars, including steel, aluminum, and glass bars. This paper discusses the status of the round robin testing. It emphasizes the importance of data analysis using h statistic and k statistic, where h statistic checks the difference between means and k statistic checks the difference between variances. The paper illustrates some case studies based on the work done so far.

Reliability Assessment of PAUT Technique in Lieu of RT for Tube Welds in Thermal Power Plant Facilities

In this study, a reliability evaluation of the phased array ultrasonic testing (PAUT) method was performed to examine the applicability of the method for tube weld specimens with flaws having the same specifications as the tubes in the boilers of thermal power plant facilities. To this end, test specimens were fabricated by inserting flaws into tube welds with identical materials and specifications to those used in the thermal power plant. PAUT data acquisition was obtained using a round robin test (RRT) on the fabricated specimen, and the data were compared with the results of radiographic testing (RT) for a comparative evaluation of the flaw detection performance. In addition, for quantitative reliability analysis, the flaw detection performance (probability of detection; POD) and the error in the sizing accuracy (root-mean-square error; RMSE) were calculated with different materials of the specimens (carbon steel, stainless steel, dissimilar metal) and flaw types (volumetric, planar). In the analysis results, for high-risk planar defects, the PAUT technique exhibited superior flaw detection performance to the RT technique. A POD analysis of the PAUT technique indicated that flaws of 6.9 mm length were detected at 80% probability for total tube specimens. Furthermore, a reliability analysis was performed for test specimens of different materials and flaw types, and the results were derived. Through the findings of this study, the applicable range of the PAUT technique was examined, and a technical basis for PAUT in lieu of RT was established.

Fracture toughness of 3Y-TZP ceramic measured by the Chevron-Notch Beam method: A round-robin study

ObjectiveThis interlaboratory round robin test investigated the robustness of the Chevron-Notch Beam (CNB) test method and the effect of the processing and testing variations on the fracture toughness of a dental 3Y-TZP ceramic. MethodsThe round robin test was performed precisely following the procedures recommended in ISO 24370:2005 and applied on a commercial 3Y-TZP ceramic (product information). A total of 335 test specimens with dimensions 3×4 x 45 mm³ was equally distributed among 10 participating laboratories of varying experience in fracture toughness testing. A standard operating procedure was defined with either narrow processing tolerances or alternative (wider) processing tolerances (as proposed in ISO 24370). Fracture toughness data (series 2) was analyzed using one way ANOVA followed by post hoc Tukey HSD test and 95% Confidence Intervals (CI) were computed (p < 0.05). A further, preceding round-robin (series 1) test was conducted with - more possible variations of test conditions regarding CNB notch processing and storage conditions. Those results are summarized in the supplement and discussed with the actual ISO 24370 test. ResultsFracture toughness of the 3Y-TZP ceramic material, summarized over all laboratories was measured to KIc = 4.48 ± 0.11 MPam0.5 for the standard processing tolerance and KIc = 4.55 ± 0.31 MPam0.5 for the alternative tolerance. The results revealed a significant influence of cutting offset and notch geometry on KIc when using CNB method. The test medium also has a significant influence on KIc in terms of reduced fracture toughness under the influence of water. With defined testing conditions the number of valid tests and reduced standard deviation increased. In case of strictly following such standard operation procedures, KIc can be determined with high reliability. There is no difference between the involved laboratories, but significant influence of cutting offset on KIC was observed. SignificanceThe CNB method is suitable method for determination of KIc on fine-grained ceramics such as 3Y-TZP ceramic. By using tighter tolerances for processing and testing, i.e. closely following the ISO 24370 procedure, a highly-precise evaluation of fracture toughness with low data variation is achievable. The information of the storage medium should always be reported along with the data. CNB fracture toughness testing is an alternative method compared to Single-edge V-notch beam (SEVNB), especially for fine-grained ceramics.

RILEM TC 258-AAA Round Robin Test: Alkali release from aggregates and petrographic analysis. Critical review of the test method AAR-8

To create an international recommendation concerning the release of alkalis, test method AAR-8 was developed within the scope of RILEM TC 258-AAA activities. The first round robin test was performed using five aggregate types, and further investigation was conducted as RRT2, leading to the final version of the AAR-8 recommendation. Five aggregates with different mineralogies and origins were immersed in specific volumes of NaOH or KOH solutions with excess calcium hydroxide maintained 38 °C and 60 °C respectively. Samples of the immersion test solution were removed at intervals of 2, 6, 13, 26, and 52 weeks by pipetting and chemically analyzed for NaOH or KOH test solutions. The amount of alkali released was expressed in grams of Na2O, K2O, and Na2Oe per kilogram of the respective aggregate. The results obtained are presented. Based on the data, several changes to the original version of the test method are proposed.

Improving consistency at testing cementitious materials in the Dynamic Surface Leaching Test on the basis of the European technical specification CEN/TS 16637–2 – Results of a round robin test

The environmental impact assessment of materials is usually based on laboratory tests, mostly in combination with models describing the longterm fate of the substances of interest in the targeted environmental compartment. Thus, laboratory tests are the fundamental link to achieve appropriate assessment conclusions which makes it essential to generate consistent results. This just as applies to the leaching of cementitious materials. In Europe, the leaching behavior of monolithic building materials is tested in the Dynamic Surface Leaching Test following the specification CEN/TS 16637–2. An interlaboratory comparison on European level regarding this technical specification showed relatively high intra- and interlaboratory variations for the tested materials (monolithic copper slag and cement stabilized coal fly ash). Therefore the German Committee for Structural Concrete (DAfStb) framed a guideline to specify additional testing conditions for cementitious materials. To assess the possible improvement by this guidelines measures, a round robin test with 11 participants from Germany and the Netherlands was conducted. This work aims to provide insight into the factors to be considered in the testing of alkaline materials, including sample preparation, and highlights crucial procedures and their manifestation in the results. All evaluated parameters showed improved results compared to the earlier round robin test. The relative standard deviations for repeatability (RSDr) and reproducibility (RSDR) of the elements calcium, barium, antimony, chromium, molybdenum and vanadium, which are the parameters evaluated in both round robin tests, were RSDr = 4%, 4%, 2%, 5%, 5%, and 5% respectively (4% in average) for this work, in comparison to the European round robin test with an average RSDr of 29% (17%, 17%, 20%, 40%, 36%, and 42%). The RSDR improved from 41% (30%, 36%, 29%, 57%, 40%, and 56%) to 14% (12%, 8%, 6%, 28%, 15%, and 12%). CO2 ingress during testing and the inaccuracy of eluate analytics for concentrations close to the determination limits were identified as the main sources of error.

Influence of testers on the ISE effect

AbstractIn the micro-hardness range of the load, the measurement is complicated by the occurrence of the Indentation Size Effect (ISE) – the measured value of the micro-hardness is affected by the value of the applied load. The paper aims to study the influence of the automatic testers on the character type and size of the ISE. Ten testers and five standard reference blocks were involved in the “round-robin test”. Parameters of the ISE were evaluated using Meyer’s, Hays–Kendall, and PSR methods and also by statistical methods (ANOVA,t-test, regression, and cluster analysis). Despite the assumptions, a statistically significant impact of the hardness tester was found not only on the measured value but also on the character and size of ISE.

How Structured Metadata Acquisition Contributes to the Reproducibility of Nanosafety Studies: Evaluation by a Round-Robin Test.

It has been widely recognized that nanosafety studies are limited in reproducibility, caused by missing or inadequate information and data gaps. Reliable and comprehensive studies should be performed supported by standards or guidelines, which need to be harmonized and usable for the multidisciplinary field of nanosafety research. The previously described minimal information table (MIT), based on existing standards or guidelines, represents one approach towards harmonization. Here, we demonstrate the applicability and advantages of the MIT by a round-robin test. Its modular structure enables describing individual studies comprehensively by a combination of various relevant aspects. Three laboratories conducted a WST-1 cell viability assay using A549 cells to analyze the effects of the reference nanomaterials NM101 and NM110 according to predefined (S)OPs. The MIT contains relevant and defined descriptive information and quality criteria and thus supported the implementation of the round-robin test from planning, investigation to analysis and data interpretation. As a result, we could identify sources of variability and justify deviating results attributed to differences in specific procedures. Consequently, the use of the MIT contributes to the acquisition of reliable and comprehensive datasets and therefore improves the significance and reusability of nanosafety studies.

Round robin tests of secondary raw materials: A systematic review of performance parameters

AbstractAn improved management of secondary raw materials (SRM) is a crucial contribution for a circular economy and necessitates knowledge about the composition of wastes and SRM. However, this information is scarce and has to be determined with chemical analysis (CA). CA of SRM faces challenges, which can be approached by using round robin tests (RRT) to identify deviations from the “true value” of an element/molecule content. An RRT is a testing approach, which involves multiple labs to analyze one or more samples and evaluates the lab results with regard to the goal of the RRT. This article presents a systematic literature review and investigates which purposes and which performance parameters (PP) are commonly applied in RRT of SRM. The examined literature shows that the two main purposes applied are assessment of method performance and assessment of lab performance. PP can be categorized into trueness performance parameters (TPP; assessing the deviation of a value from a reference value) and precision performance parameters (PPP; describing the variability of a data set). The main TPP identified arezscore and relative deviation, the main PPP identified are standard deviation and relative standard deviation. These results offer the conclusions that RRT can be used as a bespoke method to deal with analytical effects and that the selection of PP for an RRT could be based on simplicity.