TY - JOUR A1 - Trubiroha, Peter A1 - Geburtig, Anja A1 - Wachtendorf, Volker T1 - Referenzmaterialien für Bewitterungsprüfungen von polymeren Werkstoffen KW - Referenzmaterial KW - Bestrahlen KW - Bewitterern KW - Polymer PY - 2003 SN - 0341-230X SN - 1431-827X VL - 36 IS - 3 SP - 35 EP - 39 PB - Baltz CY - München AN - OPUS4-2864 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ramanujam, Maalolan A1 - Wachtendorf, Volker A1 - Purohit, Purv A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - A detailed dielectric relaxation spectroscopy study of artificial UV weathered low density polyethylene N2 - Artificial weathering of LDPE under dry conditions (<10% of relative humidity) by UV radiation was monitored by dielectric spectroscopy. For an apolar polymer like LDPE, dielectric study yields information about the change in structure and dynamics of the system. The fluctuations of the polar groups which are generated as a result of photooxidation such as carbonyl groups can be monitored as characteristic relaxation processes like the αc or β mode. The dielectric loss characterized by typical dielectric parameters like the activation energy and dielectric strength are strongly dependent upon changes induced by photooxidation in the amorphous and crystalline domains. This paper discusses in detail how the foil reached its mechanical disintegration. It was found that initial stages of weathering induce chain scission and/or crosslinking in the amorphous domains of the polymer and the motional processes in the crystalline regions are not affected. After this induction period, an increase in the degree of crystallization was observed by employing differential calorimetry. The increasing crystallinity is considered as one of the reasons for embrittlement which finally leads to the complete loss of the structural integrity. KW - Artificial weathering KW - UV radiation KW - Dielectric relaxation KW - LDPE PY - 2012 DO - https://doi.org/10.1016/j.tca.2011.12.003 SN - 0040-6031 SN - 1872-762X VL - 530 SP - 73 EP - 78 PB - Elsevier CY - Amsterdam AN - OPUS4-25547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Wachtendorf, Volker A1 - Rauth, W. A1 - Klimmasch, T. A1 - Krüger, P. T1 - Screening the weathering stability of automotive coatings by chemiluminescence N2 - Chemiluminescence (CL) is a sensitive method of investigating the thermo-oxidative stability of polymers in the early stages of degradation. Therefore, CL measurements were applied to different automotive coatings to evaluate their degradation behavior during artificial weathering. In this work, CL measurements were carried out for different automotive coatings to follow their degradation behavior during artificial weathering. The CL emission depends on sample-specific parameters like stabilizer, matrix, or hardener; experimental parameters like the oxygen partial pressure; and exposure parameters like the duration of weathering. The potential of CL could be demonstrated by classifying materials into categories of good, medium, and low degradation performance at a much earlier stage of weathering exposure than in combination with the usual visual detection of weathering effects. KW - Accelerated weathering KW - Coating KW - Chemiluminescence KW - Sensitive detection KW - Weathering PY - 2008 DO - https://doi.org/10.1007/s11998-007-9071-7 SN - 1547-0091 SN - 1935-3804 VL - 5 IS - 1 SP - 17 EP - 24 PB - Springer CY - Blue Bell, Pa. AN - OPUS4-16723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Trubiroha, Peter T1 - Accelerated weathering test for plastics and coatings that are exposed to acidic precipitation N2 - Due to the occurrence of acidic precipitation, and due to the fact that polymers and stabilizers may be sensititve to acids, it is important to have a laboratory test that combines weathering exposure with acidic exposure. The loss of stabilization caused by an acid damage of stabilizing system gets evident only over the weathering progress. For solid samples, for wich mostly the surface properties are relevant, the "Acid Dew and Fog Test" (ADF test) was established. For woven or tufted materials, the "Acid Rain Test" (AR test) was developed. The proposed weathering tests aim at plastics as well as at coatings. T2 - 7th International Symposium on Weatherability (7th ISW) CY - Kanagawa, Japan DA - 2008-10-23 KW - Acid rain KW - ADF KW - Acid Dew and Fog test KW - Artificial Weathering test PY - 2009 SN - 1346-0633 VL - 21 IS - 2 SP - 69 EP - 73 PB - Materiaru-Raifu-Gakkai CY - Tokyo AN - OPUS4-18270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Brademann-Jock, Kerstin A1 - Wachtendorf, Volker A1 - Rauth, W. A1 - Klimmasch, T. A1 - Krüger, P. T1 - Analysis of weathering effects in automotive coatings by thermoluminescence KW - Automotive coatings KW - Weathering KW - Thermoluminescence PY - 2006 SN - 0048-4225 N1 - Sprachen: Englisch/Italienisch - Languages: English/Italian VL - 82 IS - 17 SP - 5 EP - 11 AN - OPUS4-14296 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Wachtendorf, Volker A1 - Rauth, W. T1 - Kürzer in der Klimakammer - Rasche Beurteilung der Bewitterungsstabilität von 2K-PUR-Autolacken mittels Chemilumineszenz KW - Weathering KW - Chemiluminescence KW - Degradation KW - Coatings PY - 2007 SN - 0014-7699 VL - 113 IS - 9 SP - 46 EP - 49 PB - Vincentz CY - Hannover AN - OPUS4-15786 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Appajaiah, Anilkumar A1 - Wachtendorf, Volker A1 - Daum, Werner T1 - Characterization of thermo-oxidative stability of polymer optical fibers using chemiluminescence technique N2 - The thermo-oxidative stability of commercially available polymer optical fibers (POFs) and their components (cores and claddings) was investigated. All the bare POFs (core and cladding only) studied here were based on poly(methyl methacrylate) (PMMA) core. The fibers were exposed to 100 °C/low humidity for about 4200 h. Chemiluminescence (CL) technique was applied to investigate the thermo-oxidative stability and for measuring the transmission loss during exposure a prototype device called multiplexer was used. POFs exhibited variation in thermo-oxidative stability although they possessed identical core material PMMA. This was due to difference in the chemical compositions of claddings. Claddings were more susceptible to the thermo-oxidative degradation compared to cores. The thermo-oxidative degradation of both the cladding and the core was found in POFs as a result of climatic exposure. POFs showed an early drop-off followed by a slow decline of transmission. The early drop-off of transmission was attributed to physical changes like thermal expansion and the slow decline of transmission to chemical changes like oxidative degradation of POFs. A good linear relationship between optical transmission stability and thermo-oxidative stability of POFs was established from these studies. KW - Polymer optical fibers (POFs) KW - Chemiluminescence (CL) KW - Thermo-oxidative stability KW - Aging KW - Optical transmission stability PY - 2006 DO - https://doi.org/10.1016/j.polymdegradstab.2006.05.006 SN - 0141-3910 SN - 1873-2321 VL - 91 IS - 11 SP - 2605 EP - 2613 PB - Applied Science Publ. CY - London AN - OPUS4-13984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Damerau, Thomas A1 - Sabelus, Silke A1 - Wachtendorf, Volker A1 - Hennecke, Manfred A1 - Greiner, A. T1 - Photochemische und thermische Stabilität eines Phenylen-Vinylen-Polymeren KW - Photostability KW - Fluorescence KW - Chemiluminescence PY - 1996 SN - 0016-3538 VL - 40 IS - 7 SP - 710 EP - 712 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-23205 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Alterungseffekte bei Polymerwerkstoffen messen N2 - Bei der Auswahl von Werkstoffen spielt deren Alterung oft eine untergeordnete Rolle, stattdessen wird häufig der ungealterte Ausgangszustand optimiert. Materialien altern aber unterschiedlich. Der Effekt der molekularen Alterung spiegelt sich in den Eigenschaften mehr oder weniger stark und in unterschiedlichem zeitlichen Verlauf wider. Da es kein physikalisch-chemisches Modell dafür gibt, sind Alterungseffekte empirisch zu bestimmen. KW - Alterung KW - Polymerwerkstoff KW - Eigenschaftsänderung PY - 2012 DO - https://doi.org/10.1002/nadc.201290356 SN - 1439-9598 SN - 1521-3854 VL - 60 IS - 10 SP - 1018 EP - 1022 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26666 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Goedecke, Thomas A1 - Wachtendorf, Volker T1 - Combined impact of ultraviolet and chemical fluids on high-density polyethylene packaging material N2 - To investigate the ageing behaviour of filled plastic containers outdoors, square cuts of the wall of two high-density polyethylene (HDPE) types were exposed to ultraviolet (UV) radiation at their front side and to specific liquid chemicals (de-ionized water, surfactant or White Spirit) at their back. The UV radiant exposure at the front side was 80 MJ/m². To compare the actions of the different exposures, separate dark backside fluid exposures were performed, in parallel. Besides, UV weathering was carried out until a UV radiant exposure of 325 MJ/m², being roughly comparable to outdoor exposure of one year in Northern Australia. An unpigmented HDPE included in the investigation gave no sufficient protection for the White Spirit. In addition, it showed clear degradation after several of these exposures. In combination with the White Spirit, an increase of carbonyl bonds was measured, presumably assignable to degradation products of the White Spirit. For a pigmented HDPE material, with the implemented combined exposures, no relevant damage was observed, within applied the exposure period. KW - Weathering KW - UV KW - HDPE KW - Packaging PY - 2012 DO - https://doi.org/10.1002/pts.959 SN - 0894-3214 VL - 25 IS - 1 SP - 53 EP - 61 PB - Wiley CY - Chichester, UK AN - OPUS4-25417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalbe, Ute A1 - Krüger, Oliver A1 - Wachtendorf, Volker A1 - Berger, Wolfgang A1 - Hally, S. T1 - Development of leaching procedures for synthetic turf systems containing scrap tyre granules N2 - Scrap tyres are widely reused in the form of granules as infill materials or component of sub-base layers in construction of sporting grounds such as synthetic turf areas and athletic track surfaces. The recycled rubber may contain organic and inorganic pollutants due to the presence of vulcanisation catalysts, stabilisers and other additives which can be released into soil and groundwater in the case of outdoor sports facilities. In order to evaluate the amount of potentially mobile pollutants, leaching tests can be employed. This study aimed particularly at the investigation of the feasibility of column tests using complete synthetic surface flooring or turf system assemblies. The release of zinc and polycyclic aromatic hydrocarbons (PAH) leached from components of sports surfaces containing recycled rubber granules was considered. Additionally, batch tests on coated and uncoated styrene butadiene rubber (SBR) granules aged by artificial weathering were performed to indicate its possible influence on the leaching behaviour of zinc and PAH. The chosen approach of column tests simulating typical complete synthetic sports surface installations has been proven to be feasible and robust. The time-dependent leaching behaviour and interactions between single components can be evaluated by column tests. Zinc was the most relevant contaminant in the eluates and its leachability was enhanced after accelerated ageing by artificial weathering. Leachable PAH were found in relatively low but well detectable amounts which increase by ageing as well. KW - Waste rubber KW - SBR KW - Artificial turf KW - Leaching KW - behaviour KW - Column test KW - Batch test KW - Weathering PY - 2013 DO - https://doi.org/10.1007/s12649-013-9248-5 SN - 1877-2641 SN - 1877-265X VL - 4 IS - 4 SP - 745 EP - 757 PB - Springer Science + Business Media CY - Dordrecht AN - OPUS4-29454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Schmidt, Anita A1 - Goedecke, Thomas T1 - Combined impact of UV radiation and nitric acid on HDPE containers during outdoor exposure T1 - Kombinierte Einwirkung von UV-Strahlung und Salpetersäure auf HDPE-Behälter bei der Freibewitterung N2 - Unpigmented HDPE jerrycans filled with nitric acid (55%) and water respectively had been exposed to outdoor conditions for one Berlin summer season. As both liquids underwent equal temperature progression, exposure effects of UV radiation and nitric acid as well as of their combination can be separated and compared. On the basis of various property changes after these exposures, synergistic action is evaluated and compared to a damaged Intermediate Bulk Container (IBC) from a transport accident. It is found that carbonyl formation goes along with lightness increase in color measurement due to microcracking and with a worsening in mechanical behavior, all of them showing synergistic effects of UV and nitric acid exposure. In contrast, embedding nitrogen compounds goes along with yellowing of the material but cannot be correlated to oxidation. The reason for intensified damaging is the decomposition of the 55-percent nitric acid and formation of nitrogen oxides even at ambient temperatures, caused by UV radiation. Thus, damaging effects become similar to those caused by fuming nitric acid exposure at temperatures above 60 °C, with the result of strong oxidative degradation of the polyethylene. In contrast, exclusive exposure to the 55-percent nitric acid at 40 °C does not cause any failure. It can therefore be assumed that also the damaged IBC had been exposed to both UV radiation and nitric acid, probably outdoors. KW - Polyethylene KW - Nitric acid KW - UV radiation KW - Outdoor weathering KW - Resistance PY - 2018 DO - https://doi.org/10.3139/120.111148 SN - 0025-5300 VL - 60 IS - 3 SP - 257 EP - 264 PB - Carl Hanser Verlag CY - München AN - OPUS4-44567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Schulz, Ulrich A1 - Geburtig, Anja A1 - Stephan, Ina T1 - Mildew growth on automotive coatings influencing the results of outdoor weathering N2 - As the results of a 14 weeks outdoor exposure of a series of automotive coatings in South Florida, the panels were found to be overgrown with an almost closed layer of mildew. Pinholes remained as permanent surface damage after removing the mildew mycelium. The extent of the damage differed in dependence of the kind of the coating. By tracing the images and profiles of the coating surfaces systematically over all phases of weathering and the subsequent cleaning procedure, a connection between formation of pinholes and mildew growth could be found. Outdoor weathering tests in other regions of Florida as well as in Europe and Australia showed that pinholes caused by mildew attack could also be found in all other locations, but always to a lower extent than in South Florida. The standardised mildew tests EN ISO 846 and MIL-STD 810F for laboratory exposure failed to reproduce the formation of pinholes. KW - Coatings KW - Mildew KW - Weathering KW - South Florida PY - 2012 DO - https://doi.org/10.1002/maco.201005784 SN - 0947-5117 SN - 1521-4176 VL - 63 IS - 2 SP - 140 EP - 147 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Theiler, Geraldine A1 - Wachtendorf, Volker A1 - Elert, Anna Maria A1 - Weidner, Steffen T1 - Effects of UV radiation on the friction behavior of thermoplastic polyurethanes N2 - The effects of weathering exposure on unfilled and filled thermoplastic polyurethanes (TPU) materials are described as performed under different humidity conditions. For this purpose, a weathering device was used with UV-A 340 nm lamps at a constant temperature of 40 °C. The effects of environmental (UV and humidity condition) degradation on the frictional properties of TPU materials are presented along with surface analyses to characterize the chemistry of the degradative process. Photooxidative degradation of unfilled polymer leads to deterioration of physical and mechanical properties, which affects its tribological behavior significantly. Due to crosslinking, the stiffness of the material increases, reducing drastically the friction coefficient of unfilled TPUs. The frictional behavior of glass fiber reinforced TPU is less affected by radiation. KW - Photooxidation KW - UV radiation KW - Friction KW - TPU KW - Humidity PY - 2018 DO - https://doi.org/10.1016/j.polymertesting.2018.08.006 SN - 0142-9418 SN - 1873-2348 VL - 70 SP - 467 EP - 473 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-45709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erdmann, Maren A1 - Kleinbub, Sherin A1 - Wachtendorf, Volker A1 - Schütter, Jan David A1 - Niebergall, Ute A1 - Böhning, Martin A1 - Koerdt, Andrea T1 - Photo-oxidation of PE-HD affecting polymer/fuel interaction and bacterial attachment N2 - In the present study, a simple approach was used to investigate the effect of UV-exposure on two high density Polyethylene materials (PE-HD), commonly used for storage tanks, on fuel sorption behavior and colonization by microorganisms. The aim was to investigate whether the sorption behavior of the fuels (diesel/biodiesel) and the colonization by microorganisms, frequently occurring in the fuel, is affected and may lead to undesirable or safety-relevant material changes. We showed that the UV-irradiation leads to significant changes of the sorption behavior due to chemi-crystallization and crosslinking. The fuel Sorption is affected by the UV-induced formation of polar carbonyl and hydroxyl groups predominantly occurring at the surface. With respect to microbial colonization behavior for Bacillus subtilis and Pseudomonas aeruginosa, isolated from a contaminated diesel sample, differences of the initial adhesion could be shown depending on the initial type of polyethylene as well as on the degree of UV-induced degradation. KW - High density polyethylene KW - Bacterial attachment KW - UV-irradiation KW - Fuel sorption PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510001 DO - https://doi.org/10.1038/s41529-020-0122-1 VL - 4 IS - 1 SP - Article number: 18 PB - Nature Partner Journals AN - OPUS4-51000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niebergall, Ute A1 - Zanotto, M. A1 - Wachtendorf, Volker A1 - Böhning, Martin T1 - Impact of biodiesel sorption on tensile properties of PE-HD for container applications N2 - In previous papers, we investigated the influence of biodiesel or diesel on mechanical properties of a high-density polyethylene (PE-HD) for tank applications using Charpy impact tests and dynamicmechanical analysis (DMA). In this work, covering two more PE-HD materials, we extend our study to addressing the tensile properties, especially changes of Young's modulus, after immersion in biodiesel or diesel at 60 °C. As we cover sorption and desorption behavior, during desorption, i.e. storage at 60 °C in a circulating air oven, ageing or degradation phenomena were also observed and characterized in some detail using spectral reflectance measurements and FT-IR spectroscopy. The results obtained here support the concept of co-oxidation, i.e. the faster oxidation of the PE-HD matrix if the samples were previously saturated with biodiesel, itself easily oxidizable. KW - polyethylene KW - biodiesel KW - biofuels KW - sorption KW - plasticization KW - degradation PY - 2016 DO - https://doi.org/10.1016/j.polymertesting.2016.01.025 SN - 0142-9418 VL - 50 SP - 315 EP - 324 PB - Elsevier AN - OPUS4-35369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, S. A1 - Timmel, S. A1 - Gläser, M. A1 - Braun, Ulrike A1 - Wachtendorf, Volker A1 - Hagendorf, C. T1 - Polymer foil additives trigger the formation of snail trails in photovoltaic modules N2 - After several months of operation, many photovoltaic (PV) modules develop a discolouration defect called snail trails which appear as irregular dark traces across the cells. These traces are caused by silver nanoparticles accumulating within the encapsulation foil directly above the grid finger. In this work we systematically investigate combinations of encapsulation and back-sheet foils with respect to their susceptibility for snail trails. We can show that certain additive compositions within the encapsulation and back sheet foils are critical for the formation of the discolouring silver nanoparticles. We suggest a reaction model explaining the formation of snail trails from a chemical point of view. This fundamental understanding allows the rapid testing of foils for their snail trail sensitivity as well as the special design of resistant foils. KW - Snail trails KW - Encapsulation foil KW - Back-sheet foil KW - Additives KW - Silver nanoparticles PY - 2014 DO - https://doi.org/10.1016/j.solmat.2014.06.028 SN - 0927-0248 VL - 130 SP - 64 EP - 70 PB - Elsevier B.V. CY - Amsterdam [u.a.] AN - OPUS4-31249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Appajaiah, Anilkumar A1 - Wachtendorf, Volker A1 - Daum, Werner T1 - Climatic exposure of polymer optical fibers: Thermooxidative stability characterization by chemiluminescence N2 - The optical transmission stability was investigated for commercially available polymer optical fibers (POFs) which were exposed to a climate of 92°C and 95% relative humidity for about 3300 h. The optical transmission stability of POFs was correlated to their thermooxidative stability. POFs possessed identical core material, poly(methyl methacrylate), but they differed in the materials used for the claddings. The optical transmission was measured online using a prototype device called multiplexer. The chemiluminescence (CL) technique was applied to characterize the thermooxidative stability and degradation of POFs. CL analysis reveals the thermooxidative degradation of bare POFs (core and cladding), predominantly of the claddings, as a result of climatic exposure. Ultraviolet-visible transmittance measurements demonstrated more changes in the claddings as compared to the cores due to degradation. The CL and optical measurements data indicated that the optical transmission stability of POFs was dependent mainly on the thermooxidative stability of the claddings and their chemical compositions. KW - Ageing KW - Polymer optical fiber KW - Degradation KW - Chemiluminescence KW - Transparency PY - 2007 DO - https://doi.org/10.1002/app.23955 SN - 0021-8995 SN - 1097-4628 VL - 103 IS - 3 SP - 1593 EP - 1601 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-19072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chemiluminescence for the early detection of weathering effects of coatings - Part I: Fundamentals KW - Chemiluminescence KW - Weathering KW - Polymer KW - Oxidation PY - 2010 SN - 1547-0083 VL - 7 IS - 4 SP - 66 EP - 71 PB - Federation of Societies for Coatings Technology CY - Blue Bell, Pa. AN - OPUS4-21493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wachtendorf, Volker A1 - Geburtig, Anja T1 - Chemiluminescence for the early detection of weathering effects of coatings - Part II: Experimental set-up and examination KW - Chemiluminescence KW - Weathering KW - Polymer KW - Oxidation PY - 2010 SN - 1547-0083 VL - 7 IS - 5 SP - 38 EP - 44 PB - Federation of Societies for Coatings Technology CY - Blue Bell, Pa. AN - OPUS4-21494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -