Research And Development Of A Water Monitoring Device Roaming Inside Water Supply Pipelines

This paper deals with the research and development of a water qualitymonitoring device applicable to water supply pipelines. The principal part ofthe device is a water quality monitoring ball that integrates water qualityprobes, data acquisition unit, data processing and control unit, wirelesstransmission module and GSM/GPRS communication module. The waterquality monitoring ball is compact and flexible. It can either roam with wateror be fixed with cables. It monitors water quality inside the pipelines andstores the dada or transfers the information outside the pipelines via GSM orradio frequency communication.It is discovered that while the data acquisition unit is collecting electricsignals from the probes, there will be irregular noise that affects the accuracyof water quality monitoring. But arithmetic average filtering makes the signalmuch more stable and reliable. Compared with laboratory used testing devices,the water quality monitoring ball shows its liability in water qualitymonitoring.The GSM/GPRS communication module realizes the water quality inquiryof mobile phones from outside the pipelines and short message alarming whenthere are abnormalities in water quality. The communication experiments showthat GSM information can penetrate metal pipes, non-metallic pipes, water andsoil of certain thickness, and enable remote monitoring.The radio frequency communication of this device is achieved by nRF915module. It can work in433MHz,868MHz and915MHz bands. Thecommunication experiments for wireless radio frequency show that metal pipeand covered soil would affect RF communication significantly. The shieldingextend is relevant to the carrier frequency. The penetrations of differentcarriers are:915MHz>868MHz>433MHz. Carrier of915MHz can penetratemetal pipes and soil of certain thickness and enable the communication.Nonmetallic pipes, water and ambient temperature don’t affect RFcommunication obviously.A mobile handheld terminal and PC software for the upper computer arealso made. Water quality monitoring ball communicates with mobile handheld terminal and PC through wireless radio frequency. The mobile handheldterminal enables online water quality inquiry at site, and it can also adjust theoperating mode of water quality monitoring ball. The upper computer candisplay, store, and analyze water quality information.Information repeaters are designed for this water quality monitoringdevice, taking example by the aggregation node in the wireless sensornetworks, to expand its communication distance.In summary, the water monitoring device roaming inside water supplypipelines that is designed and manufactured preliminarily shows its feasibility.And it can be a new tool for in-pipe water quality monitoring as a supplementfor the traditional method.