张力计为测定土壤水势的一种仪器,其陶土头的进气值与发泡点对其性能影响的报道较少,测定其进气值与发泡点的方法也未见报道。根据水气二相流原理,本文提出了确定其进气值与发泡点的方法并用试验进行了验证。试验结果表明:(1)进气值易受饱和历史影响,测定具有不可重复性,而发泡点测试的重现性较好;(2)进气值与发泡值之间存在一定的相关性,可利用发泡值的1/4来估计张力计的适用范围,简化了测试过程;(3)吸附渗透水的概念模型和变径的毛细管模型可以解释陶土头的排水过程。 Tensiometer as a measure of soil water potential of the instrument, the ceramic head of the intake value and the bubble point on the performance of the impact of less reported to determine the intake value and the bubble point method has not been reported. According to the principle of water-gas two-phase flow, this paper presents a method to determine the value of air inlet and the bubble point and verify with the test. The experimental results show that: (1) the intake value is easily affected by the saturation history, the determination is non-repeatability, while the reproducibility of the bubble point test is better; (2) there is a certain correlation between the intake value and the foam value It can simplify the testing process by estimating the applicable range of tensiometer by 1/4 of the foaming value. (3) The conceptual model of adsorbed permeable water and the capillary tube model with variable diameter can explain the drainage process of the clay head.