Wireless sensor network for water pipe corrosion monitoring

The development of accurate corrosion models from corrosion data is a key requirement for well informed, preemptive actions towards extending the life of water infrastructure systems and reducing maintenance costs. This work presents the development of a custom proof-of-concept system implementation performing water corrosion monitoring using custom integrated corrosion sensing technologies powered by energy harvested through an in-line turbine generator. Implementing a star topology network of wireless corrosion sensor nodes distributed through water infrastructure systems offers an innovative solution for real-time and on-line monitoring of corrosion in water infrastructure systems. The wireless sensor network includes a wireless access point that provides an interface for retrieval of the corrosion data and a nexus for communications. A low-power bidirectional data transfer communications protocol using a form of time-division multiplex access is designed and implemented towards the optimisation of energy efficiency in the network. In an emulated pipeline field setup, the energy harvested and stored provides 125.80 mWh at 4.89 V for an in-pipe flow rate of 13.25 l/min, a typical value for municipal potable water supply in South Africa. The local node ER sensor can of measure changes in resistance values to an accuracy of 1% and will be usable in-system for a year. The access point implements EIS and LPR sensing. The extracted LPR value predicts a corrosion rate is 63.0 um/year in potable water.