The compact and flexible Allround-Tensiometer SITA pro line t15 measures the surface tension quickly and reliably. It has a comprehensive bubble lifetime range from 15 ms to 20 s and regulates the surface age (bubble lifetime) automatically. The three measuring modes (Single, Auto and Online) allow for adaption to the referring measuring task.
Surfactants - Measuring the surfactant concentration in aqueous solutions
Measuring the surface tension in cleaning baths enables the efficient control of surfactants.
The surface tension of an aqueous solution is dependent on the concentration of surface active substances (surfactant concentration) which can thus be determined by measuring the dynamic surface tension.
By analyzing different surfactant concentrations with the Auto-Mode a bubble lifetime that allows optimal differentiation of various concentrations is determined.
For this example a bubble lifetime of 30 ms is most suitable.
Subsequently, the optimal bubble lifetime (30 ms) is used for recording a reference curve (dependence of the surface tension from the concentration) with 7 to 9 differently concentrated approaches as shown in the picture below.
The surface tension of a sample with an unknown surfactant concentration is measured in Online-Mode or in Single-Mode using the determined bubble lifetime (30 ms).
Based on the reference curve the corresponding surfactant concentration is assigned to the measured surface tension (influence of surface active agents).
Based on the reference curve or regression function, samples with unknown concentration can be measures and thus, their concentration can be determined.