TY - CONF A1 - Gottlieb, C. A1 - Heilmann, D. A1 - Völker, Tobias A1 - Günther, Tobias A1 - Wilsch, Gerd A1 - Bohling, C. T1 - Optimization of LIBS experiments using Design of experiment (DoE) N2 - To conduct a reliable, repeatable and accurate LIBS analysis, the optimization of the experimental setup is an important task. Hardware parameters of lasers and spectrometers used in the setup as well as additionally required components such as optics or process gas pipes must be carefully aligned and adjusted because factors like (i) focal conditions of the optics, (ii) alignment of the sample, (iii) process purge gas (types, flow rate) or (iv) measurement settings (integration time, accumulation of pulses) have a big impact on the signal quality. Therefore, in most cases the effect of different factors is evaluated empirically due to changing one factor at a time while keeping the overall configuration the same. In the end, the optimal configuration is selected based on the best parameters for each influencing factor. During optimization, a configuration of the experimental setup is aimed at, which allows e.g. the highest signal intensity or the lowest variation. In most cases, cross-correlation, interference and interaction among the various factors are not considered. For this reason, the possibilities of using Design of Experiment (DoE) to optimize a LIBS experiment will be shown and advantages of (i) reduction of testing plans using a feature space, (ii) identifying and considering cross-correlations and interactions, (iii) evaluating individual impacts on the measurement (e.g. contour and surface plots) as well as (iv) multivariate models for prediction of impacts will be presented. T2 - 11th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy (EMSLIBS) CY - Online meeting DA - 29.11.2021 KW - LIBS KW - Chlorine KW - DoE PY - 2021 AN - OPUS4-53899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völker, Tobias A1 - Millar, S. A1 - Licht, M. A1 - Wilsch, Gerd T1 - Round robin test for chloride analysis in cement pastes with LIBS N2 - In civil engineering, clear regulations and standards, such as the European standard DIN EN 206 apply to ensure that the existing infrastructure is sufficiently resistant to a wide range of exposure conditions. Despite these regulations, in practice concrete structures often show severe damage during their service life. One of these damages is pitting corrosion of the reinforcement, which can be caused by chloride ingress into the structure. Therefore, determining the distribution and depth of chloride ingress is important in predicting the service life. LIBS provides an alternative method to conventional wet chemistry in civil engineering. Despite many advantages, the use of LIBS has been severely limited due to a lack of regulations. Together with project partners from research and industry, we are currently working on a leaflet that will regulate chloride analysis in civil engineering using LIBS. This year, an international round robin test was organized to evaluate the performance of LIBS for chloride analysis in cement pastes. No specifications were given for the experimental LIBS setup and data evaluation. The preliminary results are presented. T2 - 11th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy (EMSLIBS) CY - Online meeting DA - 29.11.2021 KW - LIBS KW - Cement KW - Chloride KW - Round robin KW - Interlaboratory comparison PY - 2021 AN - OPUS4-53898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -