An experimental study of the frequency response of electrochemical sensors in nonhomogeneous flow in packed beds
Abstract
Circular electrochemical probes were mounted flush with the wall of a packed bed operating either in single-phase liquid flow or in gas-liquid downflow. Frequency analysis of the measured diffusion current indicated that the recently determined mass transfer function of the probes is approximately valid, even under spatially nonhomogeneous flow conditions, provided that the relative fluctuation intensity of the current does not exceed 0.15. Correction of the current measurements in the frequency domain by means of the mass transfer function was necessary in order to determine the fluctuating characteristics of the velocity gradient.