Discussion on Measurement Uncertainty Evaluation: Applied to SEM with Liquid Cell for Particle Size Measurement of Liquid Nanoparticles

Author(s): Chun L Chiang

In recent years, the measurement of nanomaterials or nanoparticles in liquid environments using membrane-based liquid devices coupled with scanning electron microscopy (SEM) has become an important research method for real-time and dynamic measurement. However, when measuring the mean size of nanoparticles in a liquid environment, it is a random sampling measurement, and the influencing factor model of the measurement is arbitrarily complex, making it difficult to assess the statistical dispersion. This study attempts to evaluate the measurement uncertainty of the measured values according to the requirements of JCGM 100:2008. The results show that measurement errors caused by SEM system resolution are the main source of systematic measurement uncertainty. The reproducibility of measurements of different membrane-based liquid devices is the main source of random measurement uncertainty during the measurement process. Through statistical methods, it is possible to effectively reduce the measurement uncertainty of the actual nanoparticle distribution and mean nanoparticle size within a membrane-based liquid device.