TÜV SÜD (Singapore)

This paper presents recent works on traceable site-VSWR (Voltage Standing Wave Ratio) measurements for validating RF semi-anechoic chamber in 1 GHz - 18 GHz, in accordance with CISPR (International Special Committee on Radio Interference) 16-1-4 technical standard. In this work, site imperfection which is an important contributor for radiated emission measurement uncertainties, have been accurately characterized and discussed using different antenna height and polarization.

Several a posteriori indicators in the framework of local grid adaptation and large eddy simulation (LES) are evaluated. In LES indicators must be capable to bound not only the discretisation error, but also the modeling error. Moreover, the numerical method must be able to adapt the computational grid dynamically, as the regions requiring different resolution are not static. The performance of different indicators is evaluated in two flow configurations. It turns out that the classic residual based error indicator and the newly introduced heuristic indicator perform best.

This supplementary comparison is designed to test the capabilities of the participants to measure and certify carbon dioxide in nitrogen, and to provide supporting evidence for the CMCs of institutes for carbon dioxide. Indeed this comparison aims to demonstrate the capabilities of IPQ in the production of primary gas mixtures of carbon dioxide in nitrogen and for the participant laboratories to demonstrate their capabilities on certifying primary gas mixtures of percent levels of carbon dioxide in nitrogen.Moreover, a number of NMIs had already participated in the key comparison CCQM-K52, but in a lower range. This EURAMET comparison offers an opportunity to the laboratories to submit CMC in a higher range.In this comparison the laboratories analysed the gas mixtures that are gravimetrically produced and analyzed by IPQ. Each cylinder had its own reference value calculated from the gravimetric preparation. The pressure in the cylinders was approximately 10 MPa; aluminum cylinders of 5 dm3 nominal volume were used.This comparison provides evidence in support of CMCs for carbon dioxide within the range of 1.0 × 10−2 mol/mol to 20.0 × 10−2 mol/mol in a nitrogen/air balance.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Electromagnetic interference shielding coatings based on multi-walled carbon nanotubes are prepared and studied. The electromagnetic shielding effectiveness (SE) from 10 MHz to 3 GHz is measured using frequency and time domain methods. The results show that MWCNT coatings are more effective in providing EMI shielding in broad-band frequency range at thin coating layer.