Speedy calibration of low frequency vibration transducer by using linear frequency modulation signal

Aiming at calibration demands of low frequency vibration transducer and characteristics of low frequency vibration calibration system, transducer was inspired by the linear frequency modulation (LFM) signal so that its frequency characteristic could be obtained through once measurement. Calibration time reduces from a score of minutes to less than one minute, therefore its calibration efficiency improves greatly. In order to avoid the imprecise calibration result at high frequency band due to imperfect frequency characteristic of the system, digital compensation filter was designed to instantaneously compensate signal source based on the dynamic frequency characteristic of the system and time-frequency domain characteristic of LFM signal. After signal source was compensated, vibration table might give rise to more ideal LFM signal, and calibration results of transducer are closer to the absolute calibration results as well as advancement in repetition rate. This method also qualifies for calibration efficacy and accuracy, and develops the practicability of calibration system.