Automatic measurement of particle size based on scanning electron microscopy

A particle size measurement method based on micro-vision technology to improve the measuring precision is proposed in this paper. Firstly, the center point of the shape is determined by a single regular geometric boundary, and a corresponding spatial coordinate system is established. Secondly, by establishing a geometric shape size calibration model, the pixel size of basic parameters such as length, width, and cross-sectional area of the geometric shape is determined. Then, using autonomous motion calibration method, the pixel equivalent at the current image magnification is calibrated to reflect the correspondence between the pixel size of the image and the actual size, thereby expressing the actual size of the geometric shape. Finally, principal component analysis was used to compare, classify, and statistically analyze the measured geometric dimensions, eliminate duplicate values, reduce misidentification rates, and achieve accurate determination of geometric dimensions. In order to verify the validity of the method, repeat 5 times to measure the particle size of 100 nm, the experimental results show that the mean value ± standard deviation is consistent with the theoretical value. Therefore, this method reveals the possibility of high-precision measurement of particle size through computer micro-vision, and makes it be a much better option to be employed for further micro-nano structures analysis applications.