Force Tensiometer – K100

The universal instrument for analyzing surfactants and solid surfaces

The universal Force Tensiometer – K100 performs high-precision, automatic and reliable measurements of surface tension and interfacial tension, critical micelle concentration CMC andcontact angle on solids, fibers and powders. With high-quality components and a uniquely wide range of methods, the instrument carries out many tasks in the field of surfactant analysis andwetting measurement for your quality assurance or research.

High-quality components for precise measurements

The principal measuring methods used by the K100 are based on the precise measurement of the force which occurs when wetting a measuring probe or a solid sample. We use a special force sensor with a particularly high resolution for the instrument in order to obtain reliable, accurate measurements, for example for determining surface and interfacial tension or contact angle. To ensure accurate measuring results, we use measuring probes such as rings and plates with highly accurate contours. This guarantees an accurate correlation between measured force and the surface or interfacial tension.

The sample stage of our K100 has a high position resolution and, if required, can be moved very slowly and carefully. This enables the force maximum in ring measurements to be determined with great accuracy, and therefore makes this method highly reliable. As an option, the stage can also be moved very quickly for setting up measurements rapidly.

The easy-to-use keypad for controlling the sample stage, and other components such as the illumination unit or the integrated magnetic stirrer, save even more time. The keypad also enables sample stage positions to be saved so that they can be approached conveniently and automatically. With the help of this function and thanks to the large sample chamber, the sample is loaded quickly, conveniently and safely into the instrument. Magnetically locking glass swing doors shield the sample chamber from troublesome air currents.

The temperature can be accurately controlled between ‑10 and 130 °C for all measuring methods used with the Force Tensiometer – K100. This enables thermal process conditions to be simulated, for example to optimize the addition of surfactant or the wetting for a particular process. An integral, automatic stirring function ensures optimum homogenization of dispersions before measuring or rapid equalization of the concentration.

Comprehensive measuring options for particularly flexible use

As well as measuring the surface and interfacial tension using the ring, plate or rod method, the K100 provides a series of other central methods for analyzing liquids and in particular the wettability of solids. The simple changeover between different measuring methods takes place entirely without reconfiguring the instrument.

Our specially developed Micro Dispensers equip the K100 for measuring the critical micelle concentration (CMC) with the utmost precision, using one or two Dispenser units. The surfactant concentration range is set up and measured fully automatically. Working with two Micro Dispensers, where one dispenses the liquid and the other extracts the same volume, has great advantages. This enables a very wide concentration range with a high density of measuring points to be created in order to measure the CMC with high accuracy. Wrong measurements due to a too highly concentrated parent solution are virtually ruled out, as it can be diluted by several orders of magnitude and the CMC measured with high probability.

Our ionizer, which is integrated within the sample chamber, ensures reliable contact angle measurements on solid samples and single fibers. The ionizer automatically removes the troublesome effect of static charge before the measurement is carried out. Otherwise, this could falsify the result in the form of an additional force.

We have also developed accurately shaped sample holders for exactly reproducible measurements with different types of sample for measuring the contact angle on powders and fiber bundles using the Washburn method. The density of liquids can also be accurately measured with a special solid sample kit. This measuring method is particularly useful when the density is required as an input parameter for other methods, for example when measuring surface tension using the ring method.

Other measuring probes and measuring options help you with the extensive characterization of solids or dispersions. These include measuring the density of solid substances, the sedimentation speed of dispersions and the penetration resistance of a sediment.

The K100, in the basic version K100C, is available with a slightly lower resolution force sensor and without the ionizer. The K100C is ideally suited to ensuring the quality of surfactant solutions by measuring the surface and interfacial tension.

Transparency in measurement and data management

With integral and flexibly adaptable measuring templates, our LabDesk tensiometer software reduces your preparation time to a minimum. LabDesk supports simple results management with automatic overview diagrams, comprehensive measuring reports and transparent data organization, right down to the free combination of data measured with different KRÜSS tensiometers. The comprehensive and expandable substance database makes LabDesk a data pool with the substances which are important to you

Tasks and applications

• Determination of the effectiveness and efficiency of surfactants by CMC measurement
• Wetting behavior of tablets, pharmaceutical active ingredients and excipients
• Wetting of varnishes and paints
• Decomposition product content in oils
• Tank clearance and cleaning validation in the foodstuffs industry
• Wetting and adhesion of coatings
• Development of cosmetic products
• Wetting properties of inks
• Wetting of fiber bundles and textiles
• Sedimentation and ductility of dispersions
• Checking of surface modifications

Measuring methods and options

• Surface tension and interfacial tension using the ring, plate and rod method
• Surface tension and interfacial tension using the ring tear-off method, for example for measurements in accordance with ASTM D‑971
• Critical micelle concentration (CMC) of surfactants
• Contact angle and surface free energy of solids, powders or fiber bundles
• Density of liquids and solids
• Sedimentation behavior of dispersions
• Penetration resistance of sediments
• Measurement from -10 to 130 °C, temperature measurement with internal or external sensor