Ultrasonic density sensor - higher accuracy by minimizing error influences

The density of a liquid can be determined from the acoustic parameters speed of sound and acoustic impedance. Unwanted deposits in pipelines and on sensor surfaces or gas bubbles in the fluid are common problems in industrial applications of ultrasonic sensors. Results of experiments and simulations of thin layer deposits show a correlation of the time delay of the reflected echo signal and the product of layer impedance and time of flight through the layer. This can be used for layer detection and error correction. The influence of gas bubbles on frequency and amplitude of the speed of sound sensor signal is shown. A correction of the speed of sound measurement error is presented, in which signal reconstruction and processing is used.