A measurement based on error separation was used to measure the inside and outside squareness of the square. In the measurement, one squareness measuring system was used as the main standard whose error could be separated and eliminated. So this method could improve the accuracy of the measurement results. The uncertainty of measurement results are evaluated using the method in Aplac Interlaboratory Comparison Proficiency Testing Program M026 Calibration of Square, and referring to ISO/IEC Guide 98-3-2008.
With the development of science and technology, scanning electron microscope - energy dispersed spectroscopy (SEM-EDS) with its advantages of convenience, easy operation and high reliability become the most widely used instrument in micro-beam analysis field. EDS sometimes is considered as a semi-quantitative or even qualitative instrument compared with WDS and other chemical methods in element type and composition analysis. However, SEM-EDS can provide accurate results if parameters are set properly. This paper discusses how to improve the accuracy of EDS quantitative analysis by changing SEM and EDS working conditions.
Cellulose nanocrystal (CNC) is an emerging nanomaterial that has drawn increasing attention recently. It is abundant, sustainable, renewable, and biodegradable. They have unique chemical and mechanical characteristics that cannot be met by traditional cellulose-derived materials, such as high aspect ratio, low density, high stiffness, high tensile strength and very low coefficients of thermal expansion. This paper is focused on the formation and characterization of CNC films and the subsequent traceable metrology of CNC film thickness by atomic force microscopy (AFM). The AFM is calibrated by a series of certified reference materials, and thus the measured values can be traceable to the laser wavelength reference (meter definition). Results show that CNC films with negative charges on surface can be formed via physisorption to an amine-terminated thiol layer on gold through spin coating. The CNC film thickness can be controlled by CNC solution concentration. A thorough understanding of CNC metrology is the foundation for further study of CNC chemical and mechanical characteristics and applications.
With the development of science and technology, field emission scanning electron microscope (FESEM) plays an important role in nano-material measurements because of its advantages of high magnification, high resolution and easy operation. A high-quality secondary electron image is a significant prerequisite for accurate and precise length measurements. In order to obtain high-quality secondary electron images, the conventional treatment method for non-conductive materials is coating conductive films with gold, carbon or platinum to reduce charging effects, but this method will cover real micro structures of materials, change the sample composition properties and meanwhile introduce a relatively big error to nano-scale microstructure measurements. This paper discusses how to reduce or eliminate the impact of charging effects on image quality to the greatest extent by changing working conditions, such as voltage, stage bias, scanning mode and so on without treatment of coating, to obtain real and high-quality microstructure information of materials.