Study on laser diffraction measurement uncertainty comparing traditional and statistical method with virtual instrument

Assessing measurement uncertainty well and truly is the main study of this paper to resolve the problem in no contact and indirect measurement for superfine scale size. Comparing both traditional and statistical method using Fraunhofer diffraction theory to measure minuteness size, such as small slot, very thin wire or powder dimension etc, the paper presents a new experiment and study on laser diffraction measurement uncertainty. By means of assessing measurement uncertainty, the study on veracity of expressing measurement result for the method both is to give numerical value rightly on uncertainty or range possible about measurement value and account method. Based on statistical theory, the higher-accuracy survey or lower uncertainty under the condition of calculation method with Virtual Instrument is to improve measurement uncertainty on superfine scale size.