Results Of Round Robin Test Research Articles

Effects of surface treatment and weave structure on interlaminar fracture behaviour of plain glass woven fabric composites: Part II. Report of the 2nd round robin test results

This paper reports the second part of the results from the round robin test program proposed by the Society of Interfacial Materials Science (SIMS) to characterise the interlaminar fracture behaviour of E-glass woven fabric reinforced vinylester composites. Special emphasis was placed on the study of loading direction (i.e. weft and warp directions) effect on interlaminar shear strength and fracture toughness. Ten laboratories worldwide participated in this test (Table 1). Each laboratory was supplied with composite laminates and conducted the tests according to its own procedure. The results showed that although there were large variations in absolute magnitude between laboratories, a general trend was established with higher interlaminar fracture resistance in the weft direction than in the warp direction for a given silane agent. The larger number of strands running in the warp direction with rougher, more undulating areas perpendicular to the direction of crack propagation was mainly responsible for this result. The results also confirmed the previous finding that the mode I interlaminar fracture toughness increased with increasing silane agent concentration.

Calibration of straight total reflection X-ray fluorescence spectrometry — results of a European Round Robin test

Calibration of straight total reflection X-ray fluorescence measurements (TXRF) is a matter of discussion for those TXRF users who apply a droplet standard for straight TXRF measurements, at the angle of incidence where particle and film-type contamination show the same fluorescence intensity — the so-called iso-angle as Round Robin tests in the past showed. In order to gain more insight into the differences between several TXRF-equipment types and calibration methods a European Round Robin test was started in 1998 in which 12 companies participated. The Round Robin test comprises 20 different TXRF-tools and one Synchrotron Radiation (SR)-TXRF. Rutherford Back-Scattering measurements (RBS) were performed as absolute reference. Silicon wafers intentionally contaminated by spin-coating and dipping in a spiked NH 4OH/H 2O 2-solution (SC1), respectively, served as test-targets. With exception of one outlier, the results of the comparative analyses can be classified into three groups with similar values. The first group includes the RBS-results, the results of one very old Atomika tool, the results of one Rigaku-tool and those measurements based on special film-type standard wafers or an absolute TXRF calibration method. The second group, including most of the tools from the new Atomika generation, the TREX and the ESRF-beam line, shows an average deviation compared to group 1 by a factor of 1.4, and the third group, containing most of the older Atomika-tools, shows a deviation of 1.8. From these results, it can be concluded that a good calibration of straight TXRF-measurements is mainly determined by the accordance of contamination type on the calibration wafer and the unknown sample. For offsets between these, the application of the bulk sample calibration method or the use of a correction factor is needed.

Automated air void analysis on hardened concrete: Results of a European intercomparison testing program

This paper presents the results of a European round robin test on air void analysis on hardened concrete (SMT-EC-research project — Contract No. SMT4-CT95-2006). Thirteen laboratories in Europe from seven countries participated in the intercomparison test of which seven used a manual method and six an automated measurement system. The results indicate that the results obtained with measuring methods using image analysis (IA) techniques all statistically lie in the group of all measurement results. The automated methods can be problematic when a high amount of porous sand grains is present in the concrete. A second disadvantage of these automated methods is that it is not possible with the current methods being used to measure the paste content of the sample.

Thermal Conductivity of a Glass: I. Measurement by the Glass–Metal Contact

The thermal (phonon) conductivity of glass has been measured by contacting the sample with a metal at a different uniform initial temperature. The subsequent temperature response in the metal is measured by a tiny thermocouple just underneath the (contact) surface. The coefficient of heat penetration λρcp follows directly from the fitted asymptotic temperature jump or drop for long times. Division by the separately measured heat capacity ρcp yields the thermal conductivity λ. The conductivity measurement reproducibility was σ = 3%. The standard deviation between validation measurements and round robin test results on Pyrex glass was σ = 5.8%, somewhat more than the accuracy σ = 5.2% of the round robin test results. The measurement method is insensible for slight imperfections of the thermal contact and infrared radiation diffusion (photon conductivity) in a hot glass. The method has been used with minor modifications for solid and molten samples at temperatures of 50–850°C and conductivities of 0.1–25 W/(m K). The thermal (phonon) conductivity of the investigated soda-lime silicate glasses increases slightly (∼27–30%) with temperature from ambient up to around the glass transition.

Effect of surface treatment on mode I interlaminar fracture behaviour of plain glass woven fabric composites: Part I. Report of the 2nd round-robin test results

A round-robin test programme has been carried out to characterise the mode I interlaminar fracture behaviour of E-glass woven fabric reinforced vinyl ester matrix composites. Special emphasis has been placed on the effect of silane coupling agent on the stability of interlaminar crack propagation and fracture toughness. Sixteen laboratories participated in this programme. Each laboratory was supplied with composite laminates of thicknesses of its own choice and conducted the tests according to its own procedures. The results showed that variations in interlaminar fracture toughness between laboratories were very large in spite of slight differences in the test procedures used, such as specimen dimensions, test speed and data reduction schemes. Nevertheless, the general trends were clearly identified with respect to different silane coupling agents. Other observations and the implications are discussed.

Evaluation of Public Health Related Quality Aspects of Materials, Coming into Contact with Drinking Water – Odour and Flavour Tests in Particular

Objectionable odours and flavours in drinking water are a constant concern to consumers and public water suppliers. The organoleptic properties of drinking water can be naturally induced or man-made. In this paper characteristics and causes of odours and flavours are evaluated. Two methods for determining odour and flavour, in relation to the EC Directive 80/778, are described. In the Netherlands, the Netherlands Waterworks Testing and Research Institute (Kiwa) is responsible for the testing and certification of materials used in the production and distribution of drinking water. A study was undertaken to develop standards for odours and flavours in water under well defined conditions. Results of round robin tests in the period 1994 through 1997, demonstrated a considerable improvement in these methods. A valuable strategy is available for a successful localization of the causes of flavours and odours to protect consumers against health risks. Accordingly, these analytical techniques can give a complete view of impurities derived from distribution systems.

Characterization of Plasma-Sprayed Coatings Using Nondestructive Evaluation Techniques: Round-Robin Test Results

A round-robin test was implemented where nine European research institutions and universities applied different thermal, ultrasonic, and magnetic methods for measuring the thickness of plasma-sprayed coatings. The coatings, which had thicknesses ranging from 50 to 500 µm, were applied on substrates of AISI 316, a standard industrial structural material, and on Armco iron in order to have a material of known thermal properties. Destructive testing was performed after the other methods had been applied, resulting in detailed information on the coating thickness, rugosity, and uniformity. The results obtained with the applied methods on the two unknown samples for each substrate type agreed within 20% with the destructive testing data.

Evaluation of public health related quality aspects of materials, coming into contact with drinking water ?odour and flavour tests in particular

Objectionable odours and flavours in drinking water are a constant concern to consumers and public water suppliers. The organoleptic properties of drinking water can be naturally induced or man-made. In this paper characteristics and causes of odours and flavours are evaluated. Two methods for determining odour and flavour, in relation to the EC Directive 80/778, are described. In the Netherlands, the Netherlands Waterworks Testing and Research Institute (Kiwa) is responsible for the testing and certification of materials used in the production and distribution of drinking water. A study was undertaken to develop standards for odours and flavours in water under well defined conditions. Results of round robin tests in the period 1994 through 1997, demonstrated a considerable improvement in these methods. A valuable strategy is available for a successful localization of the causes of flavours and odours to protect consumers against health risks. Accordingly, these analytical techniques can give a complete view of impurities derived from distribution systems.

Inspection qualification programme for VVER reactors and review of round robin test results

Experience obtained, especially from in-service inspections of VVER 440-type reactor pressure vessels and from the Czech round test trials with international participation of ultrasonic teams, has highlighted the need for an in-service inspection qualification programme in the Czech Republic focused on NDT procedures, equipment and personnel. Recently, several national and international regional projects included in the PHARE programme (projects 4.1.2/93 and 1.02/94), briefly described, have been initiated. These projects are to cover step by step the programme of the in-service inspection qualification in view of technical justification as well as of practical assessment—performance demonstration—for all the main VVER-type primary circuit components.

Results of a complex round robin test with four river sediments

The results of a round robin test with four river sediments representing typical contamination levels in the Elbe river system are presented. Altogether 102 laboratories took part and were tested for stability and reliability of their results. A number of 54 inorganic and organic parameters were analyzed. The advantages of multivariate data evaluation compared with the univariate method are demonstrated.

Determination of O Content in Metal Powders: Results of Round Robin Tests on Co and Ni

In the powder metallurgical production of materials, the analytical characterisation of the starting powders, especially the determination of the O content, is of the utmost importance. Depending on the conditions of storage in the time between production of the powders and their processing, the very large and active surface area can cause drastic changes in the properties of the materials because chemical reactions of the adsorbed surface gases and moisture with the powders take place. In an attempt to define an analytical procedure for the accurate determination of the o content under these complex circumstances, round robin tests were organised by the Sonderwerkstoffe Working Group of the Chemists' Committee of the Gesellschaft fur Bergbau, Metallurgie, Rohstoff- und Umwelttechnik (GDMB). Furthermore, the possibilities of identifying the various O species and their distribution between surface and bulk of the powder particles (e.g. adsorbed/chemisorbed H2O, CO2, dissolved/bound oxide) by means of different heat extraction procedures were studied. The results of the investigations of Co, Ni, and WC powders are presented. PM/0757

Thermal conductivity measurements of insulating materials: results of a round-robin test between laboratories and manufacturers

Thermal conductivity measurements of insulating materials: results of a round-robin test between laboratories and manufacturers

Round Robin Testing of RTV Silicone Rubber Coatings for Outdoor Insulation

This paper presents the results of round robin tests performed to evaluate the electrical performance of Room Temperature Vulcanizing (RTV) silicone rubber coatings used for improving the contamination performance of outdoor ceramic insulators. The test, performed in six different laboratories, included several salt-fog chambers and a tracking wheel. Most test facilities were equipped with an on-line data acquisition system for measurement of leakage current activity. Four generic formulations of RTV silicone rubber coatings applied on ceramic rods were evaluated. The results indicate a general consensus in the ranking of the coatings` leakage current suppression capability, despite the variation in the experimental conditions employed. This suggests that guidelines for a laboratory test for evaluating the RTV coating material`s electrical performance under contaminated conditions could be developed.

Results of X-Ray Powder Diffraction Round Robin Tests with Corundum Plates and Powder Samples

Repetitions of the round robin test on powder diffractometer sensitivity and round robin test of intensity measurements, using two almost identical groups of participants, enabled a comparison to be made of results obtained in different tests. Two forms of corundum test samples were used: (i) sintered plates in tests A8 and A9, and (ii) powder samples in test Bl . A rough comparison of the influence of different methods of specimen preparation from the powder material in different laboratories in test Bl is thus possible with respect to the (almost) uniform sintered plates used in tests A8 and A9. The parameters under investigation were the line positions (and/or inter-planar d-spacing) and intensities of eleven reflections occurring at the 20 angles ranging from 25° to 136° for Cu Kα-radiation

Ｓ‐Ｎ曲線評価モデルの信頼性工学的検討

It has been shown from the results of round robin tests conducted under VAMAS project that the fatigue property may vary from one researcher to another due to the difference of evaluation models used. It is important to clarify the effect of the S-N evaluation model used on the reliability analysis. In this paper, the fatigue data are fitted to five regression models and the goodness of fit is investigated. The fatigue data are picked from the fatigue database which was provided by JSMS. No significant difference could be found concerning the goodness of fit against the models. However, the results differed slightly depending on the factor used in the goodness of fit. Moreover, the effect of the model on the evaluated fatigue life is investigated for the fatigue under random loads. The fatigue life evaluation was formulated for three regression models and the fatigue life under various rms values was calculated for several materials. The effect of the fatigue model on the evaluation life was clarified.

Results of the Fracture Toughness Test Round Robin on Ceramics

This report describes the results of VAMAS international round robin test for evaluating fracture toughness of ceramics. Thirteen laboratories in Japan, France, Germany, UK, Canada, Belgium and CEC (JRC Petten) took part in the test. The values of fracture toughness obtained by the SEPB, the IF and the IS methods were compared with one another for gaspressure sintered silicon nitride (GPSSN) and zirconia-alumina composites (ZAC). Also examined were indentation load dependence of fracture toughness measured by the IF and the IS methods and loading rate dependence of fracture toughness by the SEPB method. The results showed that the toughness values evaluated by the SEPB method have relatively wide scatter among the participants, suggesting some difficulty with this technique; the IS method gave the smallest scatter and the IF method the largest scatter. Fracture toughness measured by the SEPB method was dependent on the loading rate, especially for ZAC. This may have been caused by stress corroson cracking. The values measured by the IF and IS methods depended apparently on the indentation load.

Monitoring of atmospheric radionuclide releases from German nuclear power plants

Atmospheric emissions from nuclear power plants in the Federal Republic of Germany are monitored to ascertain that levels of radioactive particulates, I, 14C, 3H, noble gases and alpha -emitters remain below legal limits. Quality control is maintained through a programme of intercomparisons of data taken by plant operators and by Federal Health Office scientists, and by comparisons of short-term measurements with the results of analyses of composite samples representing a longer period. The monitoring programme is evolving as new needs become apparent and new techniques are developed. As an example of the measurements of this programme, the 1987 round-robin test results are discussed.

Crevice Corrosion Testing in Natural Seawater: Significance and Use of Multiple Crevice Assemblies

Abstract Multiple crevice assemblies (MCAs) have been used for over a dozen years to assess the crevice corrosion resistance of stainless-type alloys in seawater and other chloride-containing environments. This paper provides a review of the technique's development, modification, and present usage and discusses its limitations. Results of comparative round-robin testing and other seawater crevice corrosion studies provide perspectives on reproducibility. Insight from established corrosion mechanisms and modelling help to explain variability for some materials. Several examples of alloy rankings and beneficial effects of alloy composition determined by MCA tests are discussed.

Loudness and noisiness of a repeated impact sound: Results of round robin tests in Japan. (II).

This paper reports and discusses the results of the second stage of experiments of a round robin test on the evaluation of impact sounds. Two psychological attributes, loudness and noisiness, were dealt with in this study. The PSE's for both attributes were obtained by using the same experimental procedure. In this study, a repeated impulsive sound whose duration is 3 s at the longest was presented in a diotic listening condition. The results of the study are summarized as follows: 1) The coefficients for linear regressions of PSE on LpE (the frequency-unweighted sound exposure level) were 0.62-0.63 for loudness, while they were 0.93-1.11 for noisiness. This seems to indicate that the time constant for integration of sensation is longer for noisiness than for loudness. 2) For both loudness and noisiness, LpE showed a high correlation with PSE obtained by our experiments, and thus loudness of repeated impulsive sounds might be described by LpE with some modifications, and noisiness can be expressed by LpE with minor modifications. 3) The difference between the results of carrier signals used in this study has little effects on the experimental data.

Loundness of a single burst of impact sound: results of round robin tests in Japan (I)

This paper reports and discusses the results of a round robin test in Japan for the loudness of impact sound, which aims to establish how to evaluate the loudness, the noisiness and the annoyance of impact sounds and to describe them. As impact sounds which are encountered in daily life are characterized by high peak levels and short durations, the stimuli with such characteristics were prepared for the test: i.e. they had a short rising part (1 ms for 20 dB change), a steady part (0-100 ms) and a decaying part (30-300 ms). In this study the single burst of impact sound were presented diotically through headphones, and the method of constant stimuli was used. It is shown as the resultof the test that the sound energy level or the maximum output of an r.m.s. circuit with a time constant of 125 ms 1 s is suitable for the evaluation of stimuli. When eitherof these quantities is used, however, impact sounds are slightly louder (equivalent to 1-2 dB) than the burst of 200 ms long.