Abstract：To improve the accuracy of measuring the viscosity of nitrocellulose by falling ball method and reduce the error caused by the non-uniform movement of small ball within the falling ball distance, an accurate measurement method based on two-segment method and changing falling ball height was proposed. PLC and photoelectric sensors were used to design the experimental device. Test solutions with different viscosities were selected to obtain the timing values of different ball drop heights. The suitable drop heights were obtained by fitting the data. The measurement error of traditional and suitable drop height was compared. Experimental results show that there is a negative correlation between the suitable drop height and the viscosity of the test solution; when the viscosity is greater than 60300mPa·s, the suitable drop height is at the drop pipe orifice; when the viscosity is less than 60300mPa·s, releasing the small ball at the appropriate falling height can reduce the measurement error; the lower the viscosity, the more obvious the effect of error reduction.
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2023, Vol. 44 
