Development of a Frugal, In Situ Sensor Implementing a Ratiometric Method for Continuous Monitoring of Turbidity in Natural Waters
Author:
Sanchez Raul1, Groc Michel2ORCID, Vuillemin Renaud2, Pujo-Pay Mireille3, Raimbault Vincent1ORCID
Affiliation:
1. LAAS-CNRS, Université de Toulouse, CNRS, 31400 Toulouse, France 2. Sorbonne Université, CNRS, FR3724, Observatoire Océanologique de Banyuls, 66651 Banyuls-sur-Mer, France 3. Sorbonne Université, CNRS, UMR7621, Laboratoire d’Océanographie Microbienne (LOMIC), 66651 Banyuls-sur-Mer, France
Abstract
Turbidity is a commonly used indicator of water quality in continental and marine waters and is mostly caused by suspended and colloidal particles such as organic and inorganic particles. Many methods are available for the measurement of turbidity, ranging from the Secchi disk to infrared light-based benchtop or in situ turbidimeters as well as acoustic methods. The operational methodologies of the large majority of turbidity instruments involve the physics of light scattering and absorption by suspended particles when light is passed through a sample. As such, in the case of in situ monitoring in water bodies, the measurement of turbidity is highly influenced by external light and biofouling. Our motivation for this project is to propose an open-source, low-cost in situ turbidity sensor with a suitable sensitivity and operating range to operate in low-to-medium-turbidity natural waters. This prototype device combines two angular photodetectors and two infrared light sources with different positions, resulting in two different types of light detection, namely nephelometric (i.e., scattering) and attenuation light, according to the ISO 7027 method. The mechanical design involves 3D-printed parts by stereolithography, which are compatible with commercially available waterproof enclosures, thus ensuring easy integration for future users. An effort was made to rely on mostly off-the-shelf electronic components to encourage replication of the system, with the use of a highly integrated photometric front-end commonly used in portable photoplethysmography systems. The sensor was tested in laboratory conditions against a commercial benchtop turbidimeter with Formazin standards. The monitoring results were analyzed, obtaining a linear trendline from 0 to 50 Nephelometric Turbidity Unit (NTU) and an accuracy of +/−0.4 NTU in the 0 to 10 NTU range with a response time of less than 100 ms.
Funder
CNRS 80|Prime program French National Program LAAS-CNRS micro and nanotechnologies platform FEDER European Regional Funds and French Région Occitanie
Subject
Electrical and Electronic Engineering,Biochemistry,Instrumentation,Atomic and Molecular Physics, and Optics,Analytical Chemistry
Reference35 articles.
1. Lambrou, T.P., Panayiotou, C.G., and Anastasiou, C.C. (2012, January 28–31). A low-cost system for real time monitoring and assessment of potable water quality at consumer sites. Proceedings of the IEEE Sensors, Taipei, Taiwan. 2. Matos, T., Faria, C.L., Martins, M.S., Henriques, R., Gomes, P.A., and Goncalves, L.M. (2019). Development of a cost-effective optical sensor for continuous monitoring of turbidity and suspended particulate matter in marine environment. Sensors, 19. 3. Trevathan, J., Read, W., and Schmidtke, S. (2020). Towards the development of an affordable and practical light attenuation turbidity sensor for remote near real-time aquatic monitoring. Sensors, 20. 4. Implementation and calibration of an iot light attenuation turbidity sensor;Trevathan;Internet Things,2022 5. Sadar, M. (2011). Turbidity Measurement: A Simple, Effective Indicator of Water Quality Change, OTT Hydrome.
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|