Round-robin testing

As a first step in the direction outlined here some manufacturers and BAM last year discussed the problems and the possible procedures of such a system of quality assurance. As a result of this meeting round robin tests for the harmonization of the measurements of film system parameters and a possible procedure of surveillance of the quality of film systems were proposed. Closely related to these the BAM offers to perform the classification of film systems. But as during the production of films variations of the properties of the different batches cannot be avoided, the results of measurements of films of a single batch will be restricted to this charge, while only the measurements and mean of several batches of a film type will give representative values of its properties. This fact is taken into account already in section 4 of the standard EN 584-1 which can be interpreted as a kind of continuous surveillance. In accordance with this standard a film system caimot be certified on the base of measurements of a single emulsion only. 

A first comprehensive round robin test described in 4.1 which is open to all interested parties will be followed periodically by round robin tests in a reduced extent to ensure the further harmonisation of measurement procedures. The check of measurering equipments and procedures is an inalienable requirement for the further steps for providing the users with constant film quality. Together with sample tests performed by BAM as indicated in section 4.2 and and the production control by the manufacturer it will be possible to survey the film systems whether they meet the requirements of one of the film classes of EN 584-1. 

In case of mixed systems the procedure must be varied and it would be restricted to the special film systems of interest, of course. Mixed systems would be used by inspection companies and industrial users who normally do not dispose of the equipment for measurements as mentioned above. In these cases instead of a round robin test only periodical measurements of the properties of these mixed film systems by an independent third party institution can be used for film classification and continuous surveillance. 

Round robin tests for the harmonization of the measurements of film system parameters according to EN 584-1... 

At the beginning of the supervision of films systems first of all the influences of the exposure-and processing installations of the project partners on the determination of the film system parameters shall be found out and subsequently the equipments for measurement shjdl be compared one with another. This round robin test comprises in detail ... 

The detection sensitivity of radiography is related among others to the properties and quality of industrial x-ray film systems. Changes of the products, variations due to different emulsions and combinations of products of different manufacturers can influence the decisive properties of film systems as classified in EN 584-1.To ensure the quality of industrial x-ray film systems a system for quality assurance open to all interested parties is proposed which is based on periodical round robin tests and quality controls of the manufacturer or an independent third party institution. 

Figure 1. Average corrected emission spectrum (- -) and excitation spectrum (- -) for quinine sulfate In 0.1 mol/L HC10 obtained during round-robin test with ten laboratories coefficient of variation at each wavelength (-t).

Analysis of variance (ANOVA) tests whether one group of subjects (e.g., batch, method, laboratory, etc.) differs from the population of subjects investigated (several batches of one product different methods for the same parameter several laboratories participating in a round-robin test to validate a method, for examples see Refs. 5, 9, 21, 30. Multiple measurements are necessary to establish a benchmark variability ( within-group ) typical for the type of subject. Whenever a difference significantly exceeds this benchmark, at least two populations of subjects are involved. A graphical analogue is the Youden plot (see Fig. 2.1). An additive model is assumed for ANOVA. 

The same parameter is tested on at least two samples by each of several laboratories using the same method (round-robin test 3 2 ), or... 

Standardisation of EPDM characterisation tests (molecular composition, stabiliser and oil content) for QC and specification purposes was reported [64,65]. Infrared spectroscopy (rather than HPLC or photometry) is recommended for the determination of the stabiliser content (hindered phenol type) of EP(D)M [65]. Determination of the oil content of oil-extended EPDM is best carried out by Soxhlet extraction using MEK as a solvent [66], A round robin test was reported that evaluated the various techniques currently used in the investigation of unknown rubber compounds (passenger tyre tread stock formulations) [67]. 

Takadama, H., Hashimoto, M., Mizuno, M. and Kokubo, T. (2004) Round-robin test of SBF for in vitro measurement of apatite-forming ability of synthetic materials. Phosphorus Research Bulletin, 17, 119-25. 

Rautio, M. "An International Interlaboratory Round-Robin Test for Chemical Warfare Agents." Kemia-Kemi 18 (1991) 19-21 (In Finnish). 

Round-Robin-Teste bezeichnen Priifverfahren, an deren Ausarbeitung sich verschiedene Institute in verschiedenen Landern zum Zweck der... 

When round robin tests were performed to test the reproducibility of these standard procedures, large coefficients of variation between laboratories were obtained for tin-free paints (78-80% and 24-32% for the ISO and ASTM methods respectively Haslbeck and Holm, 2005). These discrepancies have multiple sources such as the analytical method (Haslbeck and Holm (2005) report 4-54% deviations when different laboratories measuring samples of known concentration), the sea water conditions both in the holding tank and the measuring tank (Haslbeck and Holm, 2005), the sample preparation for analysis... 

Arias, S. Round robin test for antifouling paints. European Coatings Journal 03 (1999). 122-128. 

Haslbeck, E.G., Holm, E.R. Round robin test for measuring copper release rates from antifouling coatings. In preparation for publication in the European Coatings Journal 2005. 

Despite the promising possibilities offered by the different types of nanoparticles, their routine use is still strongly limited by the very small number of commercially available systems and the limited amount of data on their reproducibility (in preparation, spectroscopic properties, and apphcation) and comparability (e.g., fluorescence quantum yields, stability) as well as on their potential for quantification. To date, no attempt has yet been published comparing differently functionalized nanoparticles from various sources (industrial and academic) in a Round Robin test, to evaluate achievable fluorescence quantum yields, and batch-to-batch variations for different materials and surface chemistries (including typical ligands and bioconjugates). Such data would be very helpful for practitioners and would present the first step to derive and establish quality criteria for these materials. 

In a round robin test conducted as a work package within the European Thematic Network for Wood Modification, considerable differences in decay resistance were found... 

Leithoff, H., Peek, R.D., Borck, V., Gottsche, R., Kirk, H. and Grinda, M. (1999). Toxic values derived from EN113 tests—are they determined by the virulence of the test fungus —Results from a round robin test. International Research Group on Wood Preservation, Doc. No. IRGAVP 99-20176. 

Youden, W.J. (1963), Ranking Laroratories by Round-Robin Tests, Materials Research Standards, 3,9-13. 

It has been noted in a round robin test of microcomposites that there arc large variations in test results for an apparently identical fiber and matrix system between 13 different laboratories and testing methods (Pitkethly et al., 1993). Table 3.1 and Fig 3.15 summarize the IFSS values of Courtaulds XA (untreated and standard surface treated) carbon fibers embedded in an MY 750 epoxy resin. It is noted that the difference in the average ISS values between testing methods, inclusive of the fiber fragmentation test, fiber pull-out test, microdebond test and microindentation test, are as high as a factor of 2.7. The most significant variation in ISS is obtained in the fiber pull-out /microdebond tests for the fibers with prior surface treatments, and the microindentation test shows the least variation. 

Collated data obtained from all laboratories in a round robin test programme ... 

O Brien, T.K. and Martin, R.H. (1992). Results of ASTM round robin testing for mode I interlaminar fracture toughness of composite materials, NASA TM 104222. 

D. Berek, Repeatability and apparent reproducibility of molar mass values for homopolymers determined by size exclusion chromatography, lUPAC Round Robin Test, General Assembly of lUPAC, Brisbane, Australia, 2001. 

Today, as a direct solid-state analytical technique, dc GDMS is more frequently applied for multi-element determination of trace contaminants, mostly of high purity metallic bulk samples (or of alloys) especially for process control in industrial laboratories. The capability of GDMS in comparison to GD-OES (glow discharge optical emission spectrometry) is demonstrated in a round robin test for trace and ultratrace analysis on pure copper materials.17 All mass spectrometric laboratories in this round robin test used the GDMS VG 9000 as the instrument, but for several... 

Furthermore, isotope standard reference materials are required in different chemical forms for a multitude of elements in order to calibrate and evaluate isotope ratio measurements by mass spectrometry. In addition, reliable analytical data required in science and routine work will only be obtained by improving the quality assurance of the measurement procedures and also using interlaboratory comparisons of analytical results in round robin tests. 

The need for improving the reliability of characterization of polymers has long been evident. Other efforts in this direction include the round-robin testing conducted at various times, beginning in 1950, under the auspices of the Commission of Macromolecules of IUPAC (I, 2, 3), as well as the work now in progress in ASTM concerned with establishing standardized methods of characterization. 

To reach steady state, the residence time of the fluid in a constant stretch rate needs to be sufficiently long. For some polymer melts, this has been attained however, for polymer solutions this has proved to be a real challenge. It was not until the results of a world wide round robin test using the same polymer solution, code named Ml, became available that the difficulties in attaining steady state in most extensional rheometers became clearer. The fluid Ml consisted of a 0.244% polyisobutylene in a mixed solvent consisting of 7% kerosene in polybutene. The viscosity varied over a couple of decades on a logarithmic scale depending on the instrument used. The data analysis showed the cause to be different residence times in the extensional flow field... 

Chesler, S. "The Round Robin Test Materials and a Summary of the Results," Consortium on Automated Analytical Laboratory Systems, 2nd CAALS Workshop on Supercritical Fluid Extraction of Solid Environmental Samples, November 8, 1991, NIST, Gaithersburg, MD. 

Cowgill, U.M. (1986) Why round-robin testing with zooplankton often fails to provide acceptable results, in T.M. Poston and R. Purdy (eds ), Aquatic Toxicology and Environmental Fate 9th Volume, ASTM STP 921, American Society for Testing and Materials, Philadelphia, PA, pp. 349-356. 

Thellen, C., Blaise, C., Roy, Y. and Hickey, C. (1989) Round Robin testing with the Selenastrum capricomutum microplate toxicity assay, in M. Munawar, G. Dixon, C.I. Mayfield, T. Reynoldson and M.H. Sadar (eds.), Environmental Bioassay Techniques and their Application Proceedings of the Is International Conference held in Lancaster, England, 11-14 July 1988, Kluwer Academic Publishers, Dordrecht, Netherlands, pp. 259-268. 

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