Tensiometrien

Tensiometrien, or tensiometry, refers to a set of methods and instruments used to measure mechanical tension and related properties in liquids, materials, and biological systems. The term covers both surface or interfacial tension in fluids and the measurement of tension or suction in porous media and tissues. Tensiometric techniques aim to provide quantitative values that characterize how a liquid interacts with its surroundings or how a system bears or transmits force.

In chemistry and materials science, tensiometry commonly measures surface tension, which is the cohesive force at a liquid’s surface. Interfacial tension between immiscible liquids is also assessed. Widely used methods include the Wilhelmy plate and Du Noüy ring techniques, which rely on known geometries and force balance principles, as well as pendant drop and capillary methods that analyze the shape or behavior of liquid columns. Modern tensiometry often employs optical, microbalance, or automated digital analysis to improve accuracy and repeatability. Typical outputs are surface tension values expressed in milliNewtons per meter (mN/m) or interfacial tension values in similar units.

In soil science and agronomy, tensiometers measure matric potential or soil water tension to gauge plant-available water. These devices use a water-filled tube with a porous tip connected to a pressure sensor; changes in suction reflect moisture status, aiding irrigation management and hydrological studies.

In medicine and physiology, tensiometry can describe blood pressure measurement in some contexts, especially where devices assess arterial tension using sphygmomanometers or oscillometric methods. Tensiometry can thus encompass both laboratory analyses of liquids and biomechanical assessments.

Historically, notable tensiometric methods were developed by researchers such as Wilhelmy and Du Noüy, whose techniques laid the groundwork for routine surface and interfacial tension measurements. Limitations include temperature sensitivity, sample purity, and the need for calibration, but tensiometry remains central to characterization in chemistry, materials science, soil physics, and physiology.