Study on Experimentation of LDVT Frequency Band Characteristics

This paper presents a novel testing apparatus designed to evaluate the frequency characteristics of Linear Variable Differential Transformer (LVDT). The proposed system incorporates a rotary wheel displacement actuation mechanism to comprehensively investigate the dynamic behaviors of LVDTs. Key components include a servo motor, rotary wheel, sliding rail, LVDT fixture, the sensor under test, conditioning circuitry, acquisition equipment, and an upper computer. By employing controlled displacement simulation through the servo motor and sinusoidal signals, the system applies the linear sweep method to analyze the response of the LVDT across various frequency ranges. Experimental data is leveraged to derive the mathematical model of the LVDT, thus obtaining its transfer function. Notably, the amplitude bandwidth and phase bandwidth of the tested LVDT are essentially equal. The work demonstrates that it is feasible to study the frequency band characteristics of the sensor by inputting sinusoidal signals of the same magnitude but different frequencies into the displacement sensor and applying spectral analysis methods.