{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T12:01:26Z","timestamp":1771329686820,"version":"3.50.1"},"reference-count":29,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2018,4,6]],"date-time":"2018-04-06T00:00:00Z","timestamp":1522972800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Turbidity sensing is very common in the control of drinking water. Furthermore, turbidity measurements are applied in the chemical (e.g., process monitoring), pharmaceutical (e.g., drug discovery), and food industries (e.g., the filtration of wine and beer). The most common measurement technique is nephelometric turbidimetry. A nephelometer is a device for measuring the amount of scattered light of suspended particles in a liquid by using a light source and a light detector orientated in 90\u00b0 to each other. Commercially available nephelometers cost usually\u2014depending on the measurable range, reliability, and precision\u2014thousands of euros. In contrast, our new developed GRIN-lens-based nephelometer, called GRINephy, combines low costs with excellent reproducibility and precision, even at very low turbidity levels, which is achieved by its ability to rotate the sample. Thereby, many cuvette positions can be measured, which results in a more precise average value for the turbidity calculated by an algorithm, which also eliminates errors caused by scratches and contaminations on the cuvettes. With our compact and cheap Arduino-based sensor, we are able to measure in the range of 0.1\u20131000 NTU and confirm the ISO 7027-1:2016 for low turbidity values.<\/jats:p>","DOI":"10.3390\/s18041115","type":"journal-article","created":{"date-parts":[[2018,4,10]],"date-time":"2018-04-10T13:06:08Z","timestamp":1523365568000},"page":"1115","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Low-Cost GRIN-Lens-Based Nephelometric Turbidity Sensing in the Range of 0.1\u20131000 NTU"],"prefix":"10.3390","volume":"18","author":[{"given":"Michael","family":"Metzger","sequence":"first","affiliation":[{"name":"Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany"},{"name":"Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander","family":"Konrad","sequence":"additional","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Felix","family":"Blendinger","sequence":"additional","affiliation":[{"name":"Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Modler","sequence":"additional","affiliation":[{"name":"Department of Mathematics, Physics and Chemistry, Beuth University of Applied Sciences, 13353 Berlin, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alfred","family":"Meixner","sequence":"additional","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Volker","family":"Bucher","sequence":"additional","affiliation":[{"name":"Institute for Applied Research, Faculty for Mechanical and Medical Engineering, Furtwangen University, 78054 Villingen-Schwenningen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5537-1448","authenticated-orcid":false,"given":"Marc","family":"Brecht","sequence":"additional","affiliation":[{"name":"Institute of Physical and Theoretical Chemistry, University of Tuebingen, 72076 Tuebingen, Germany"},{"name":"Process Analysis and Technology (PA&amp;T), Reutlingen Research Institute, Reutlingen University, 72762 Reutlingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,4,6]]},"reference":[{"key":"ref_1","unstructured":"Lawler, D.M. 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