Thermische Dehnung

Thermophysical Extension

Bestimmung der Thermischen Dehnung Delta (L)/Lo [%] bzw. Ausdehnungskoeffizienten CTE [K-1] (Coefficient of Thermal Expansion) mittels Schubstangendilatometer

Abb.: Dilatometer DIL 402 / Netzsch

The two pushrod dilatometers DIL 402 C from Netzsch cover two temperature ranges: -160°C to 500°C and RT to 1550°C. The push rod movement due to the change in length of the sample is detected by an inductive displacement transducer (LVDT). The electrical signal is evaluated in the TA - System Controller.

This data acquisition system controls automatically all parameters like heating, cooling rate, threshold values, offsets, etc. of the measurement too. Calibration and correction curves respectively are done by mean of a fused silica reference standard, delivered by PTB for materials with low expansion and a NBS platinum standard for middle and higher expansion. Change in length, uncorrected and corrected, physical and technical expansion coefficient are given. Pushrod contact pressure can be adjusted between 15 and 50 cN. Tube sample holder, carried out by fused silica and Al2O3 for higher temperatures, and furnace chamber are mounted horizontally and can be used in vacuum or desired atmosphere, static or dynamic.

Two devices are available for the temperature range -160°C up to 500°C and RT up to 1550°C. Sample diameter is possible from 3 to 5 mm, max. length 25 mm. The error is better than 3%.

These dilatometers are regularly used for measurement on metallic and non-metallic materials; the evaluation and documentation of data is performed automatically. The measurements are performed according international standards, for the most important ones the department is an accredited testhouse according to according to EN 45000.