Monitoring of fouling within pipes using Electrical Impedance Spectroscopy

The objective of the study described in this paper was to evaluate a monitoring system for fouling in pipes, based on impedance measurements using only one fixed frequency. The monitoring system observed the fouling growth (deposition layer and corrosion) inside a pipe which was subjected to a constant flow of liquid. The measurement frequency was specifically selected to optimize the sensitivity of the monitoring system towards the fouling growth. An electrical potential difference was applied to the pipe to generate an electrical field to accelerate the fouling growth in the experiment. Experimental results show a measurable change in the impedance magnitude (fouling growth) over the duration of the experiment (8 weeks). Results indicate that the measurement system, using one fixed frequency, is capable of in-situ monitoring of fouling growth in a pipe with a continuous flow of liquid.