Research on Portable Resonant Density Meter

A resonant density meter is a sensor used to measure the density of a fluid, where a change in density causes a change in the mass loading of the resonator structure, resulting in a change in the resonant frequency. In this article, key properties of mechanical resonators that determine the overall performance of density meter are described. The traditional straight tube or U-shaped tube structure is not suitable for portable equipment, so a resonator with a double-tube structure is designed. Since the two straight tubes vibrate in opposite directions, the bending moment and vibration force are canceled at the root, so that the sensor does not need counterweight. First, through theoretical derivation, a physical model of the resonant sensor is established, and the expressions of frequency and quality factor are derived. Next, the structure and circuit of the sensor are introduced, and finally the experiment proves that the sensor has excellent stability.