Equipment for measurement of nonlinearity of nominally linear components

Nonlinearity of a nominally linear component is a significant parameter, which informs about the difference of and investigated component from an ideal one. The higher is quality of the nominally linear component; the lower is level of its nonlinearity. Nonlinearity is caused by inhomogenities and unstable barriers in the component, which can, after some time, cause failure of the component. Nonlinearity is also a significant technical parameter of components, which work with more signals of different levels. Nonlinearity contributes here to generation of intermodulation distortion of current signals. It has been necessary, for our research, to investigate nonlinearity of adhesive joints. Because there is not equipment for measurement of nonlinearity of low-impedance components on the market, it has been necessary to construct it. Equipment is based on evaluation of intermodulation distortion, which is generated by the nonlinear component, when two sinusoidal signals are fed into it. Equipment makes a measurement of nonlinearity of 2. to 5. order possible. Measured level of nonlinearity is -170 dB with respect to the actuating signal. Maximum power of the actuating signal is 2 VA, the sensitivity of an indicator 50 nV. Some examples of measurements of nonlinearity of adhesive joints are shown.