{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T21:58:13Z","timestamp":1777931893333,"version":"3.51.4"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2013,4,19]],"date-time":"2013-04-19T00:00:00Z","timestamp":1366329600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The high cost of what have historically been sophisticated research-related sensors and tools has limited their adoption to a relatively small group of well-funded researchers. This paper provides a methodology for applying an open-source approach to design and development of a colorimeter. A 3-D printable, open-source colorimeter utilizing only open-source hardware and software solutions and readily available discrete components is discussed and its performance compared to a commercial portable colorimeter. Performance is evaluated with commercial vials prepared for the closed reflux chemical oxygen demand (COD) method. This approach reduced the cost of reliable closed reflux COD by two orders of magnitude making it an economic alternative for the vast majority of potential users. The open-source colorimeter demonstrated good reproducibility and serves as a platform for further development and derivation of the design for other, similar purposes  such as nephelometry. This approach promises unprecedented access to sophisticated instrumentation based on low-cost sensors by those most in need of it, under-developed and developing world laboratories.<\/jats:p>","DOI":"10.3390\/s130405338","type":"journal-article","created":{"date-parts":[[2013,4,19]],"date-time":"2013-04-19T11:00:47Z","timestamp":1366369247000},"page":"5338-5346","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":100,"title":["Open-Source Colorimeter"],"prefix":"10.3390","volume":"13","author":[{"given":"Gerald","family":"Anzalone","sequence":"first","affiliation":[{"name":"Department of Civil and Environmental Engineering, Michigan Technological University,  1400 Townsend Drive, Houghton, MI 49931, USA"}]},{"given":"Alexandra","family":"Glover","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Michigan Technological University Houghton, 1400 Townsend Drive, Houghton, MI 49931, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9802-3056","authenticated-orcid":false,"given":"Joshua","family":"Pearce","sequence":"additional","affiliation":[{"name":"Department of Materials Science and Engineering, Michigan Technological University Houghton, 1400 Townsend Drive, Houghton, MI 49931, USA"},{"name":"Department of Electrical and Computer Engineering, Michigan Technological University Houghton, 601 M&M Building, 1400 Townsend Drive, Houghton, MI 49931, USA"}]}],"member":"1968","published-online":{"date-parts":[[2013,4,19]]},"reference":[{"key":"ref_1","unstructured":"The Open Source Definition (Annotated). Available online:http:\/\/opensource.org\/docs\/definition.html."},{"key":"ref_2","unstructured":"94 Percent of the World's Top 500 Supercomputers Run Linux. Available online: https:\/\/www.linux.com\/news\/enterprise\/high-performance\/147-high-performance\/666669-94-percent-of-the-worlds-top-500-supercomputers-run-linux."},{"key":"ref_3","unstructured":"75% of Top 10k Websites Served by Open Source Software. Available online:http:\/\/royal.pingdom.com\/2012\/05\/22\/75-percent-top-10k-websites-served-by-open-source-software\/."},{"key":"ref_4","unstructured":"Survey: 98 Percent of Enterprises Using Open Source Software, Interrupted\u2014CNET News. Available online: http:\/\/news.cnet.com\/8301-13846_3-20013258-62.html."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1077","DOI":"10.1126\/science.1196984","article-title":"Open source physics","volume":"334","author":"Christian","year":"2011","journal-title":"Science"},{"key":"ref_6","first-page":"47","article-title":"Appropedia as a tool for service learning in sustainable development","volume":"3","author":"Pearce","year":"2009","journal-title":"J. Edu. Sustain. Dev."},{"key":"ref_7","unstructured":"Buitenhuis, A.J., Zelenika, I., and Pearce, J.M. (2010, January 25\u201327). Open Design-Based Strategies to Enhance Appropriate Technology Development. San Francisco, CA, USA."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1007\/s10668-012-9337-9","article-title":"The case for open source appropriate technology","volume":"14","author":"Pearce","year":"2012","journal-title":"Environ. Dev. Sustain."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1126\/science.334.6054.308","article-title":"Open-source ecology takes root across the world","volume":"334","author":"Stokstad","year":"2011","journal-title":"Science"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1088\/0957-4484\/12\/3\/303","article-title":"Open sourcing nanotechnology research and development: issues and opportunities","volume":"12","author":"Bruns","year":"2001","journal-title":"Nanotechnology"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Maclurcan, D., and Radywyl, N. (2012). Nanotechnology and Global Sustianability, CRC Press.","DOI":"10.1201\/b11833"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1038\/491519a","article-title":"Make nanotechnology research open-source","volume":"491","author":"Pearce","year":"2012","journal-title":"Nature"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"714","DOI":"10.1126\/science.1199349","article-title":"Advancing global health research through digital technology and sharing data","volume":"331","author":"Lang","year":"2011","journal-title":"Science"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1372","DOI":"10.1126\/science.1211936","article-title":"Imaging of plasmodium liver stages to drive next-generation antimalarial drug discovery","volume":"334","author":"Meister","year":"2011","journal-title":"Science"},{"key":"ref_15","unstructured":"Acosta, R. (2009). Open Source Hardware. [MS.c. Thesis, Massachusetts Institute of Technology]."},{"key":"ref_16","unstructured":"Sells, E., Bailard, S., Smith, Z., Bowyer, A., and Olliver, V. (2009). Handbook of Research in Mass Customization and Personalization, Forthcoming, World Scientific."},{"key":"ref_17","unstructured":"RepRap\u2014RepRapWiki. Available online:http:\/\/www.reprap.org\/wiki\/Main_Page."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1017\/S026357471000069X","article-title":"RepRap\u2014The replicating rapid prototyper","volume":"29","author":"Jones","year":"2011","journal-title":"Robotica"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1303","DOI":"10.1126\/science.1228183","article-title":"Building research equipment with free, open-source hardware","volume":"337","author":"Pearce","year":"2012","journal-title":"Science"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Deek, F.P., and McHugh, J.A.M. (2007). Open Source: Technology and Policy, Cambridge University Press.","DOI":"10.1017\/CBO9780511619526"},{"key":"ref_21","unstructured":"Settle, F.A. (1986). Chemical instrumentation, evolution of instrumentation for uv-visible spectrophotometry. J. Chem. Edu."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"8613","DOI":"10.3390\/s91108613","article-title":"Investigations of bread production with postponed staling applying instrumental measurements of bread crumb color","volume":"9","author":"Popov","year":"2009","journal-title":"Sensors"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1996","DOI":"10.3390\/s90301996","article-title":"Sensory properties and color measurements of dietary chocolates with different compositions during storage for up to 360 days","volume":"9","year":"2009","journal-title":"Sensors"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"5961","DOI":"10.3390\/s8095961","article-title":"Color changes of UHT milk during storage","volume":"8","year":"2008","journal-title":"Sensors"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1108\/02602280710731632","article-title":"Optical chemical sensors for industrial applications","volume":"27","author":"Bogue","year":"2007","journal-title":"Sens. Rev."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Terry, P.A. (2010). Application of ozone and oxygen to reduce chemical oxygen demand and hydrogen sulfide from recovered paper processing plant. Int. J. Chem. Eng.","DOI":"10.1155\/2010\/250235"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"228","DOI":"10.2307\/3223218","article-title":"A photoelectric colorimeter for estimating protozoan population densities","volume":"68","author":"Elliot","year":"1949","journal-title":"Trans. Amer. Microsc. Soc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1802","DOI":"10.2105\/AJPH.86.12.1802","article-title":"Assessing children's ultraviolet radiation exposure: The potential usefulness of a colorimeter","volume":"86","author":"Eckhardt","year":"1996","journal-title":"Amer. J. Pub. Health"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/0379-0738(96)01939-1","article-title":"Photometric assessment of skin colour and lightness using a tristimulus colorimeter: Reliability of inter and intra-investigator observations in healthy adult volunteers","volume":"81","author":"Trujillo","year":"1996","journal-title":"Foren. Sci. Int."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2915","DOI":"10.1016\/S0043-1354(00)00036-1","article-title":"Use of water quality indices to verify the impact of C\u00f3rdoba City (Argentina) on Suqu\u00eda River","volume":"34","author":"Pesce","year":"2000","journal-title":"Water Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2460","DOI":"10.3390\/s100402460","article-title":"Estimation of biological oxygen demand and chemical oxygen demand for combined sewer systems using synchronous fluorescence spectra","volume":"10","author":"Hur","year":"2010","journal-title":"Sensors"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"972","DOI":"10.3390\/s120100972","article-title":"Prediction of BOD, COD, and total nitrogen concentrations in a typical urban river using a fluorescence excitation-emission matrix with PARAFAC and UV absorption indices","volume":"12","author":"Hur","year":"2012","journal-title":"Sensors"},{"key":"ref_33","unstructured":"OpenSCAD\u2014The Programmers Solid 3D CAD Modeller. Available online:http:\/\/www.openscad.org\/."},{"key":"ref_34","unstructured":"Slic3r-G-Code Generator for 3D Printers. Available online: http:\/\/slic3r.org\/."},{"key":"ref_35","unstructured":"Arduino-HomePage. Available online:http:\/\/www.arduino.cc\/."},{"key":"ref_36","unstructured":"Adafruit Industries Unique and Fun DIY Electronics and Kits. Available online: https:\/\/www.adafruit.com\/."},{"key":"ref_37","unstructured":"United States Environmental Protection Agency (1983). Methods for Chemical Analysis of Water and Wastes, EPA."},{"key":"ref_38","unstructured":"Gonzales, J. (1995). Wastewater Treatment in the Fishery Industry, Food and Agriculture Organization of the United Nations."},{"key":"ref_39","unstructured":"Hach Company Oxygen Demand, Chemical, Method 8000 for Water, Wastewater and Seawater. Available online:http:\/\/www.hach.com\/asset-get.download.jsa?id=7639983640."},{"key":"ref_40","unstructured":"Colorimeter V0.0. Available online:http:\/\/www.thingiverse.com\/thing:45443."},{"key":"ref_41","unstructured":"Open-Source Colorimeter. Available online:http:\/\/www.appropedia.org\/Open-source_colorimeter."},{"key":"ref_42","unstructured":"Arduino and the Taos TSL230R Light Sensor: Getting Started\u2014Drone Colony. Available online:http:\/\/dronecolony.com\/2008\/11\/13\/arduino-and-the-taos-tsl230r-light-sensor-getting-started\/."},{"key":"ref_43","unstructured":"Smart Lab Technology. Available online:http:\/\/www.iorodeo.com\/."},{"key":"ref_44","unstructured":"Educational Colorimeter Kit. Available online:http:\/\/www.iorodeo.com\/colorimeter."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Zhang, C., Anzalone, N.C., Faria, R.P., and Pearce, J.M. (2013). Open-Source 3D-Printable Optics Equipment. PLoS ONE.","DOI":"10.1371\/journal.pone.0059840"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/13\/4\/5338\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:46:15Z","timestamp":1760219175000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/13\/4\/5338"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,4,19]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2013,4]]}},"alternative-id":["s130405338"],"URL":"https:\/\/doi.org\/10.3390\/s130405338","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,4,19]]}}}