Factors affecting the performance of the bimorph-based dilatometer for field induced strain measurement of polymer films

摘要

This article gives a detailed discussion about the design and performance of a bimorph-based dilatometer using different sensor heads and platforms both experimentally and theoretically. A current preamplifier in high-pass filter mode was used to optimize the signal and a protective circuit was introduced. The test results demonstrated that the best signal occurred when the lengths of stainless steel pin and bimorph were both 10.0 mm and that the resonant frequency was inversely proportional to the square of the sensor length. Some suggestions for reducing the noise and improving the sensitivity were also provided.