| 摘要 |
<p>An improved apparatus and method are disclosed for measuring the dynamic surface tension at a gas-liquid interface by the maximum bubble pressure method. The gas is bubbled out an orifice tube dipped in the liquid; the maximum pressure in each bubble is a function of the surface tension. In the invention, the rate of gas flow is raised continually to increase the rate of bubbling at least several fold over a few minutes. The varying pressure of the bubbling gas is measured continuously by an instantaneous transducer. Electronic circuits respond to the transducer and provide signals indicative of the maximum bubble pressure and of the rates of bubbling. A recorder responds to the signals and displays a spectrum of the maximum bubble pressure in units indicative of surface tension as a function of the bubbling rate. Measurements may be taken over more than a thousand bubbles in each spectrum. The rise in gas pressure is achieved by passing gas from a source under pressure in series through two flow-restricting capillaries, with an accumulator zone between.</p> |
