摘要
本文描述了近几年发展的电容—电压或电容频率测量技术,即相敏电容桥。该测量系统由计算机控制,测定频率范围为30Hz-10kHz、利用STN—0020/01SBE液晶材料在不同温度条件下测定了弹性常数K_(11)～14.9×10^(-12)N.K_(33)～15.3×10^(-2)。在玻璃板上镀金膜作为液晶分子平行取向排列层兼作为电极。本测试系统的误差和精度分别在电容值的测量误差为±5％,正弦波(30Hz—10KHz)的频率精度±1％、给出弹性常数K_(11)、K_(22)、K_(33)的误差为±5％～±10％。
The technique allied C-V or C-F method which was developed in recent years to measure the elastic constants of liquid crystal materials were described. It is also called phase sensitive capacitance bridge method. The measuring system is controlled by a computer.
The frequency range covers from 30Hz to 10kHz. The elastic constant's of LC were measured at different temperatures. The elastic constants of STN-0020 01SBF (Roche Ltd ) are ~ 11.9 - 15.8 ?10 10N at room tamperature. A thin layer of gold was deposited on the glass suostrates. The homogeneous of LC was observed through the experiment. Tne precision of the method was
confined by the accuracy of capacitiance measurement, and the error was within± 5%. The precision of the measuring frequency of the sine wave is about , the total deviation of elastic constants K and K is 10.
