High Flowrate and Low Detection Limit Single-Particle Ultrasonic Sensor

Abstract

Single particle detection by ultrasound scattering is demonstrated. Polystyrene particles with a diameter of 40 $\mu \text{m}$ are individually counted using a visual spectrogram method. As an alternative a less computationally expensive algorithm for the data analysis using Hilbert transform is also demonstrated. Experiments demonstrating the particle counting capabilities of the sensor for different flow rates and concentrations are shown and linear relationships are observed as expected. The sensor differs from other particle counters by handling high flow–rates (>800 L h−1) and having an extremely low detection limit of about 0.5 particles per mL in 1s, which is orders of magnitudes better than the ones for analogues optical particle sensors.