Measuring Equipment » Bubble Pressure Tensiometer MPT C

Method

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LAUDA MPT - worldwide one of the only device that operates on the Fainerman Method

As the MPT 2, in the MPT C, the pressure is not measured inside the bubble as is customary in other devices, but in a buffer volume before the capillary. There, the pressure always corresponds to the maximum bubble pressure from which, using the known internal radius of the capillary, the surface tension can be derived.

An integrated pump produces a gas flow that is held constant at the respective specified value. For measurement, a gas, usually air, is introduced into the sample through a very narrow capillary. Depending on the gas flow rate, either a jet or individual bubbles are produced. In the jet range, the gas flow is proportional to the pressure drop along the capillary. At a certain point, the jet will split up into individual bubbles. The pressure now serves to inflate the bubble and, according to LaPlace, depends from this point forward on the surface tension and bubble radius.

The MPT is the only instrument based on the Fainerman method and allows surface tensions to be determined precisely at previously unavailable surface ages of less than one millisecond!