Abstract: In view of the problems of existing radioactive or poor anti-interference performance of the pipeline slurry on-line detection densimeter，a new resonant pipeline slurry densimeter was developed. Based on the vibration mathematical model of fluid pipeline，this densimeter measured the difference between the vibration frequency of the instrument and the frequency of fluid flowing through the instrument to judge the concentration of the slurry liquid. The pulp densimeter is mainly composed of a vibrating tube with liquid，an inductance coil distributed around the inner wall of the vibrating tube cavity，a resistor and capacitor connected with the two lead-outs of the inductance coil， and a RLC series resonance circuit with inductance coil，resistor and capacitor, etc. The MIMR-XZ6 pipeline slurry densimeter can be used as on-line density detector of pulp materials, and its detection accuracy can meet the needs of industrial.

Key words: Liquid density meter, Vibrating tube, RLC series resonant circuit, Excitation signal