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.
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.
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.
An entire set of measurement scheme was designed to measure a granite rectangular square of (2000×1600) mm in size. Each angle was measured separately using the squareness measurement system, and data processing was then carried out using closure principle. A dedicated slider with air-bearing was also designed to obtain more stable and reliable data.
In view of the dispute on the placement of material sensor when measuring the positional accuracy of a linear axis of a CNC machine tool, this paper presents the method and principle of deciding where to put the material temperature sensor. The positional accuracy of the linear axis of the machine tool is one of the most important performance parameters, and it must be measured when setup and check. The placement of the material temperature sensor has great influence on the measurement accuracy. At present, there are two main views on this issue: one is to place the sensor on the table of the machine tool, the other is to place it on the feedback system. This conflict between these two debates often makes the measurers feel confused and as a result influences the measure quality, sometimes. This thesis attempts to classify the CNC machine tools positional accuracy measurement according to its different purposes, then further presents the best placement. The thesis also elaborates other relevant questions of the placement of the material temperature sensor.