Najji H. AlYami, Abdullah S. AlOwaysi, Khaled M. Ahmed
Traceable in-house preparation of RM CO2/N2 gas mixture using gravimetric standardized method

The necessity for national and international programs to monitor the levels of carbon dioxide emissions in the atmosphere has arisen as a result of the recent large greenhouse gas emissions that cause a rise in the Earth's temperature and climate changes with severe impacts. In order to give confidence in the monitoring results and enable the proper decisions to be made regarding the supply of environmental treatment and air quality through the limiting and monitoring of emission, it is required to maintain the traceability of the measurement data to SI units. Gas measurements laboratory at SASO-NMCC uses the gravimetric method to prepare reference gas mixtures of CO2 in N2 as primary standard mixtures (PSMs) cylinders based on universal gas law. The produced PSMs used as working standards to transfer the traceability from CRMs to customers’ artefacts. The used method fully complies with ISO 6142. Description of the steps of the production process and its method verification as well as equipment used and associated uncertainty are presented in this work. In accordance with the requirements of ISO 6143, a validated gas chromatography thermal conductivity detector (GC-TCD) method was selected to verify the mole fraction of the gravimetrically prepared gas mixtures. Reproducibility of the produced concentrations is demonstrated through mid-term and long-term evaluations. Eight certified reference materials (CRMs) of different concentrations were used for the GC calibration to provide metrological traceability of the measurement results to SI units. Associated uncertainty budget, with brief description of different components and error sources, is presented

Florbela A. Dias, Cristina Palma, Carlos J. Costa
Preparation of multicomponent mixtures to support carbon metrology

The Reference Gas Laboratory (LGR) of IPQ is participating in the project MetCCUS - Metrology for Carbon Capture Utilization and Storage under the new EPM (European Partnership on Metrology) Program. The goal of this project is to develop a metrological infrastructure that enables monitoring and detection of carbon dioxide leaks in energy and industrial processes, in transport networks and also allow the support of a better understanding of the life cycle of carbon dioxide. The contribution of LGR involves the preparation of certified reference materials (CRM) to allow the metrological traceability, providing support for the calibration and validation of instrumentation used in carbon capture processes.

Valnei Smarçaro da Cunha, Romeu José Daroda, Júlio Dutra Brionizio, Marcos Paulo Vicentim, Fernanda Figueiredo Nunes, Graziele Mozzer Pereira, Thais Fagundes da Silva
Assessment of moisture absorption by anhydrous ethanol under different environmental conditions

The main use of bioethanol in the world is as a fuel by adding it to gasoline. The addition of ethanol has many purposes, such as increasing gasoline octane number, reducing carbon dioxide emissions by fossil fuels, energy security and environmental sustainability. The suitable bioethanol for mixing in gasoline is the anhydrous one, which must contain up to a maximum of 1% (w/w) of water, according to ASTM D5798-21 [1]. Although it is well known that ethanol is a hygroscopic substance, a complete study addressing the rates of moisture absorption by the ethanol and its evaporation, or showing the influence of the environmental conditions on these factors cannot be found in literature. The assessment of these behaviours is fundamentally relevant for all the ethanol production and distribution chain in order to estimate how long an ethanol batch can be handled keeping the water content, or even to avoid significant loss of ethanol by evaporation, resulting in environmental problems and financial losses. In order to evaluate the ethanol behaviour under different environmental conditions, in this work, as a preliminary study, several environments with different relative humidities and temperatures were simulated in a climatic chamber, and their impact on the moisture absorption rate and/or on the ethanol evaporation were analysed in some anhydrous ethanol samples. It was also evaluated if moisture absorption or ethanol evaporation is the preferential process.

C. Daniel, A. R. Dablio, R. Damian, M. Lagmay, J. A. Valdueza, J. E. Guerrero, M. A. Principe
Validation of a method for the extraction and quantification of water-soluble chloride in cement by ion chromatography

Chloride is a corrosive anion that can attack steel and other metal embedded materials in concrete structures leading to its degradation. Chloride in concrete may come from the materials used for making concrete such as cement. Hence, it is important to have a reliable method for determining chloride in cement, in this case the water-soluble chloride which is representative of chloride that may pose corrosion risk. In this study, ASTM C1218/C1218M-20 was used as a guide for sample extraction and the water-soluble chloride was later quantified by ion chromatography. Validation of this method from extraction to instrumental determination was conducted by assessment of the linear range, detection limit, precision, and trueness. It was found that the method was suitable for the determination of water-soluble chloride content in cement.

M. Cundeva-Blajer, Gj. Dimitrovski, K. Demerdziev
Implementation and Validation of Calibration Methods in the Area of High Frequencies

The paper presents a methodology for calibration of high-frequency instruments, such as oscilloscopes, counters and function generators operating above 1 MHz up to GHz level. The methods were developed at the Laboratory for Electrical Measurements at Ss. Cyril and Methodius University in Skopje, following the Calibration Guide EURAMET cg-7. The paper also discusses the challenges of setting up measurement traceability chain and uncertainty evaluation. These methods are important for the region of Southeast Europe, where the metrology facilities for calibration/testing of high frequency electronic devices are not sufficiently developed to meet the needs of the fast-growing automotive supply chain sector.