Optical non-contact dilatometer – CTE expansion measurement

Description

The DIL L74 OD (Optical Dilatometer) was developed to meet the demanding applications of the glass-ceramics, metal industry and energy industry to fulfil. A high-resolution CCD camera enables visual real-time analysis of the sample expansion – either as a single image or as a video sequence.

The advantage of this method is that no force is applied on the sample, so no mechanical deformation takes place. In the case of soft samples or samples that change their strength during the measurement, the result can always be affected by the contact pressure of a classic push rod dilatometer. The optical dilatometer can help to overcome or minimize this influence.

The LINSEIS software integrates several correction and analysis functions and the unique horizontal design enables the most demanding applications. The special solid-liquid adapter is an extension and enables volume measurements of solids, liquids and solid-liquid phase transitions. A special sample holder is also available for measuring rigid foils, which would bend too much when measured by push rod dilatometer due to the forces acting on them.

Measuring principle

In an optical dilatometer, the sample is permanently compared with a reference during the measurement. The reference is typically a known material with defined expansion and acts as a live correction to overcome optical fluctuations due to atmospheric effects during heating. The field of view has an area of 3.3 x 2.8 mm2 and is typically focusing on the upper edge of the sample.