Wetting under extreme conditions – that is the special field for DSAHT. The instrument measures the contact angle and surface tension, which makes it possible to optically record sample deformation at temperatures up to 1750°C under different atmospheres.

• Contact angle measurement
• Measurement of surface tension
• Image recording of the sample shape with single frames and video sequences 
• Temperature measurement in the immediate proximity of the sample 
• High-contrast image from transmitted light despite heat induced sample emissions
• Quick and comfortable sample loading 
• Built-in gas and vacuum connections

A world class furnace design combined with years of experience in optical measurement techniques makes the DSAHT an instrument full of ideas for successful high-temperature optical studies.

Controlled temperature: Many possibilities are open to users - from setting a single target temperature up to programming time-controlled ramps and cycles. The long length of the furnace tube guarantees a homogeneous temperature distribution in the sample area and a favourable temperature gradient between the flanges resulting in an extended lifetime. The temperature sensor is embedded in the sample table so that the temperature is measured directly beneath the sample.

Done in a few steps: With the aid of flanges and a sliding device, the furnace is opened quickly,  then loaded and closed again. The sample can also be aligned even when the furnace is closed. As the working tube is mechanically separated from the heating elements it can be exchanged with little fuss.

Keeping a sharp eye: The camera is equipped with a zoom focusing lens that permits continuous observation of the sample: on the screen, as single frames or as a video sequence.

Crystal clear images: The DSAHT creates a sharp, high-contrast image of the glowing sample. This technical achievement is possible thanks to a filtering technique that allows light from the light source to pass through whist preventing the transmission of sample-emitted light.

A versatile system: With different versions from 1200°C, 1500°C up to 1750°C, KRÜSS provides the optimum instrument for the required target temperature. In all temperature ranges, the working tube can be operated under different atmospheres: oxidizing, inert, reducing. The appropriate gas connections are built in as standard, as is a pump connection for working under vacuum (up to 1000°C).

Temperature measurement, image recording and drop shape analysis: All the threads are gathered together in the DSA software. An optional software module reads out the temperature sensor and starts the measurement. In this way, the contact angle and surface tension, measured simultaneously or singularly, can be plotted as a function of temperature or time.

Several proven and robust methods are available for measuring the contact angle of favourably or poorly wetting drops. The surface tension is calculated from the curvature of the drop shape.

As an alternative to online evaluation, a video recording of the sample can also be programmed. Recording time and image recording rate can be set at individual steps in the measurement thus allowing both long-term behaviour and rapid changes in a particular temperature range to be saved into a single video file for post-processing.