Since non-standardized conditions resulted in poor repeatability and reproducibility of test results as well as failure to measure some of the powder contact angle during the powder contact angle measurement test

this paper studied the impact of such external factors on the powder contact angle test as compactness of the powder column

number of layers and height of the wrapped filter paper and the selection of dipping liquid. Following results were obtained: the compactness of the powder column remarkably influenced the discreteness of the powder contact angle

where the more stable the compactness was

the smaller discreteness we got; such external factors as number of layers and height of the filter paper wrapped at bottom of the glass tube and the selection of dipping liquid imposed direct impact on whether we could get results of the powder contact angle

especially to powders with greater grain size; powders with bigger grain size needed more layers of filter papers wrapped at the bottom; in order to get results of the contact angle of the powders smoothly

we needed to make the top surface of the wrapped filter paper at bottom of the glass tube above the liquid level and to select the polar liquid with non-zero dispersion component of surface energy parameter components.