Abstract: This paper introduces a self-made instrument, which is used to accurately determine the viscosity coefficient of liquid by the flow rate method. Our self - made measuring instrument could ensure effectively the product with a good leak - proof quality on the bottom board and the operability to control the height of the liquid keep with the steady flow. Moreover, we additionally build a glass joint implement, and attach a scale and vernier, which improves the accuracy of measurement. With the photoelectric timing at the graduated cylinder connected with the capillary tube, the flow measurement accuracy is greatly improved. Then, the relevant data into the procedures have been calculated properly and electronic devices demonstrate viscosity. In addition, another design can be swapped for different diametric capillary tubes. Consequently, this method can be applied quickly and accurately to determine a variety of liquid viscosities.

Key words: self - made instrument, liquid, viscosity coefficient, flow rate method