... Impedance Analyzer are mainly applicable to all types of ultrasound devices for measuring impedance characteristics, including: ... L1, free capacitor CT, the free dielectric constant, mechanical quality factor Qm, electromechanical coupling coefficient Keff , Kp, ... to replace the Agilent 4294A, including the Institute of Acoustics, Chinese Academy of Sciences, Qinghua University, Panyu Dewey, which ...