A low-cost autonomous optical sensor for water quality monitoring

Kevin Murphy, Brendan Heery, Timothy Sullivan, Dian Zhang, Lizandra Paludetti, King Tong Lau, Dermot Diamond, Ernane Costa, Noel O'Connor, Fiona Regan*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

76 Citations (Scopus)


A low-cost optical sensor for monitoring the aquatic environment is presented, with the construction and design described in detail. The autonomous optical sensor is devised to be environmentally robust, easily deployable and simple to operate. It consists of a multi-wavelength light source with two photodiode detectors capable of measuring the transmission and side-scattering of the light in the detector head. This enables the sensor to give qualitative data on the changes in the optical opacity of the water. Laboratory tests to confirm colour and turbidity-related responses are described and the results given. The autonomous sensor underwent field deployments in an estuarine environment, and the results presented here show the sensors capacity to detect changes in opacity and colour relating to potential pollution events. The application of this low-cost optical sensor is in the area of environmental pollution alerts to support a water monitoring programme, where multiple such sensors could be deployed as part of a network.

Original languageEnglish
Pages (from-to)520-527
Number of pages8
Publication statusPublished - 15 Jan 2015
Externally publishedYes


  • Environmental monitoring
  • In-situ sensing
  • Low-cost sensors
  • Optical sensor
  • Water quality

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