演示水的沸点随压强而变化的实验,常见的有淋水法及抽气法。淋水法需要解释为什么淋水后可以降低容器中的压强,讲解上不够简便。利用抽气法常使抽气玻璃罩上濛上水汽,不易观察。下面介绍一个直接抽气的方法,现象明显,并且可以演示增压、降压两种现象。 Demonstration of the boiling point of water with the pressure changes experiments, common water law and pumping method. Water law need to explain why water can reduce the pressure in the container, explain not enough simple. The use of suction often make the exhaust glass covered with water vapor, not easy to observe. The following describes a direct suction method, the phenomenon is obvious, and can demonstrate booster, blood pressure two kinds of phenomena.