Differential Pressure-Based Densitometer in Dynamic Condition

Change in density will cause errors in measurement for indirect-based level sensing approaches, such as capacitive sensors. In addition, there is growing attention in measuring density accurately not only in laboratory conditions but also in a real-time dynamic environment. To address the above-mentioned issues, an independent instrument based on differential pressure sensors is proposed in this article. Synchronous detection is used to detect the desired signal by calculating the coefficients of the digital Fourier transform. The characterization of the sensor is experimentally determined under a steady-state condition, where a linear response is observed. The thermal behavior of the proposed sensor is studied and compensated using the polynomial fitting technique. Evaluating the uncertainty due to reference values, linearity, and repeatability, the obtained results show a combined uncertainty lower than 7.5 (mg/cm3), mainly limited by observed asymmetric hysteresis at higher temperatures.