测定大气压强值的托里拆利实验是初二物理教学的一项重要演示实验。准备该实验的所有教师都有排灌水银困难之感。原因是:托里拆利管内径小,从上向下灌水银时受管内气体阻碍,不可能一次顺利注满,而且在管内壁难免附着微小气泡,不易排出,影响测定值的准确度。为了排尽气泡,不通 The Torricelli experiment for determining atmospheric pressure is an important demonstration experiment in the second physics teaching. All the teachers who prepared the experiment had the difficulty of draining mercury. The reason is as follows: the inner diameter of the Torelli tube is small, and the gas in the tube is hindered when pouring mercury from the top to the bottom. It is impossible to fill the tube smoothly, and it is difficult to avoid attaching tiny bubbles on the inner wall of the tube and it is difficult to discharge, affecting the accuracy of the measured value. In order to exhaust air bubbles, nowhere