插板法测表面张力公式的新证明及讨论

从力平衡的角度，建立固液接触角为零度时插板外液体的物理数学模型，推导证明液体表面形状曲线方程，然后证明固液接触角不为零度时的一般情况，为测量依据公式提供一种新的证明方法，最后，通过讨论得出３点有意义的结论。（１）对于一定的液体，不同材料插板 起液体上升的实际高度不同，但最高固液接触点都落在同一曲线上。（２）可以通过测量直线距离代替接触角的作测，以提高表面张力的精度。（３）由直线距离测量所得表面张力

New Proof and Discussion on the Formula for Measuring Surface Tension by Neumann Method

From the angle of force balance,a physical and mathematical model of liquid outside the insert plate when the angle of solid liquid contact equals to zero is established; and the surface curve shape of liquid is derived and proved. And then, the general conditions during which the angle of solid liquid unequal to zero degree are derived and proved. By way of discussion, three meaningful conclusions are obtained: (1) For a certain liquid, the actual height of the rise of the liquid differs with the insert plates of different materials, however, all the highest points of solid liquid contact fall on the same curve. (2) The accuracy of the surface tension can be promoted by measuring line distance instead of angle of contact.(3) The relative errors for surface tension calculated by line distance are twofold of the relative errors for measuring line distance.