一、引言若用杜瓦瓶作为恒温装置,用差分毛细上升技术测定液体在低温下的表面张力可能是困难的。问题的产生是由于许多玻璃壁的光学性能一般不够好,而采用通常的高差计法测定弯月面的高度差时,又要通过这些玻璃壁。在一定 I. INTRODUCTION If dewar is used as a thermostat, it may be difficult to determine the surface tension of liquids at low temperatures using the differential capillary ascending technique. The problem is caused by the fact that many glass walls are generally poor in optical properties and pass through the glass walls when measuring the meniscus height difference by the usual height difference method. In a