Abstract: Measuring pulp density (concentration)，has been a technical problem in mining industry，pulp density (concentration) measurement accuracy directly affects the level of control and the effect of the mineral processing automation control.Design of a new type resonant density (concentration) analyzer is based on the principles of the vibration damping components.The instrument is mainly driven by tuning fork sensor，detection circuit，main control chip，auxiliary circuit，and the corresponding shell.Excitation coil makes the tuning fork vibrate when concentration meter works，the vibration frequency detected by piezoelectric crystal.It is converted to the electrical signals of the measure needs after through the moving phase and amplifying circuit.When fluid flows through the body vibration fork，the change of the resonance frequency caused by the change of fluid quality，instrument collection system collected the frequency shifts.Due to the different density of fluid flowing through the vibration system will produce different vibration frequency，using the function relation between the vibration frequency and the density calculate the density value of the flowing fluid after the instrument detected the vibration frequency shifts.Finally，the density value of the flowing fluid will be calculated.Application of resonant density (concentration) analyzer in a plant in Nanjing indicated that，the device can improve the Accuracy and reliability in density measurement of mineral processing.

Key words: Non-direct-contact, Resonant, Density (concentration) analyzer