Comparative validation of amperometric and optical analyzers of dissolved oxygen: a case study
- 109 Downloads
A comprehensive comparative validation for two different types of dissolved oxygen (DO) analyzers, amperometric and optical, is presented on two representative commercial DO analyzers. A number of performance characteristics were evaluated including drift, intermediate precision, accuracy of temperature compensation, accuracy of reading (under different measurement conditions), linearity, flow dependence of the reading, repeatability (reading stability), and matrix effects of dissolved salts. The matrix effects on readings in real samples were evaluated by analyzing the dependence of the reading on salt concentration (at saturation concentration of DO). The analyzers were also assessed in DO measurements of a number of natural waters. The uncertainty contributions of the main influencing parameters were estimated under different experimental conditions. It was found that the uncertainties of results for both analyzers are quite similar but the contributions of the uncertainty sources are different. Our results imply that the optical analyzer might not be as robust as is commonly assumed; however, it has better reading stability, lower stirring speed dependence, and typically requires less maintenance. On the other hand, the amperometric analyzer has a faster response and wider linear range. Both analyzers seem to have issues with the accuracy of temperature compensation. The approach described in this work will be useful to practitioners carrying out DO measurements for ensuring reliability of their measurements.
KeywordsElectrochemical sensors/mass sensitive sensors Optical sensors/luminescent sensors Validation Dissolved oxygen
This research was supported by the EU through the European Regional Development Fund (TK141 “Advanced materials and high-technology devices for energy recuperation systems”) and by the Ministry of Education and Science of Estonia (institutional research grant no. IUT20-14).
- Clesceri, L. S., & American Public Health Association, American Water Works Association, and Water Pollution Control Federation (Eds.). (1998). Standard methods: for the examination of water and wastewater (20th ed.). Washington: American Public Health Ass.Google Scholar
- Garcia, H. E., Locarnini, R. A., Boyer, T. P., Antonov, J. I., Baranova, O. K., Zweng, M. M., et al. (2010). World ocean atlas 2009 Volume 3: Dissolved Oxygen, Apparent Oxygen Utilization, and Oxygen Saturation. Sydney Levitus, Ed. Washington, D.C.: NOAA Atlas NESDIS 70, U.S. Government Printing Office Available at: http://www.nodc.noaa.gov/OC5/indprod.html.
- HACH Company. (2006). HQ series portable meters, USER MANUAL, edition 5.Google Scholar
- Häck, M. (2006). Optical measurement of oxygen concentration in water. Available at: https://cz.hach.com/cms/documents/parameter-4-downloads-1.pdf. Accessed December 7, 2017.
- Hellat, K., Mashirin, A., Nei, L., & Tenno, T. (1986). Metrological garanteeing of devices for measuring oxygen in the water. Acta et Commentationes Universitatis Tartuensis de Mathematica, 757, 184–193.Google Scholar
- ISO 17289:2014. (2014). Water quality—determination of dissolved oxygen—Optical sensor method.Google Scholar
- ISO 5814:2012. (2012). Water quality. Determination of dissolved oxygen. Electrochemical probe method.Google Scholar
- ISO/IEC 17043:2010. (2010). Conformity assessment—general requirements for proficiency testing (This standard replaces the ISO Guides 43–1 and 43–2).Google Scholar
- JCGM 100:2008. (2008). Evaluation of measurement data—guide to the expression of uncertainty in measurement. Available at: https://www.bipm.org/utils/common/documents/jcgm/JCGM_100_2008_E.pdf.
- Jessen, G. L., Lichtschlag, A., Ramette, A., Pantoja, S., Rossel, P. E., Schubert, C. J., Struck, U., & Boetius, A. (2017). Hypoxia causes preservation of labile organic matter and changes seafloor microbial community composition (Black Sea). Science Advances, 3, e1601897. https://doi.org/10.1126/sciadv.1601897.CrossRefGoogle Scholar
- Langie, B., & Lewandow, M. (1999). Comparison between polarographic and galvanic dissolved oxygen sensor technologies. Available at: http://www.4oakton.com/TechTips/OAK_TT25.pdf. Accessed May 5, 2017.
- Liu, H., Gu, Y., Kim, J. G., & Mason, R. P. (2004). Near-infrared spectroscopy and imaging of tumor vascular oxygenation. In Methods in Enzymology (pp. 349–378). Elsevier. https://doi.org/10.1016/S0076-6879(04)86017-8.
- Magnusson, B., Näykky, T., Hovind, H., & Krysell, M. (2012). Handbook for calculation of measurement uncertainty in environmental laboratories (NT TR 537 - Edition 3.1). Available at: http://www.nordtest.info/index.php/technical-reports/item/handbook-for-calculation-of-measurement-uncertainty-in-environmental-laboratories-nt-tr-537-edition-3.html.
- Mancy, K. H., & Jaffe, T. (1966). Analysis of dissolved oxygen in natural and waste waters. Cincinnati: U.S. Dept. of Health, Education, and Welfare, Robert A. Taft Sanitary Engineering Center.Google Scholar
- McKeown, J. J., Brown, L. C., & Gove, G. W. (1967). Comparative studies of dissolved oxygen analysis methods. Journal - Water Pollution Control Federation, 39, 1323–1336.Google Scholar
- Mortimer, C. H. (1981). The oxygen content of air-saturated fresh waters over ranges of temperature and atmospheric pressure of limnological interest. Stuttgart: Schweizerbart Science Publishers Available at: http://www.schweizerbart.de//publications/detail/isbn/9783510520220/Mitteilungen_IVL_Nr_22.Google Scholar
- Tengberg, A., Hovdenes, J., Andersson, H. J., Brocandel, O., Diaz, R., Hebert, D., Arnerich, T., Huber, C., Körtzinger, A., Khripounoff, A., Rey, F., Rönning, C., Schimanski, J., Sommer, S., & Stangelmayer, A. (2006). Evaluation of a lifetime-based optode to measure oxygen in aquatic systems: lifetime-based optode to measure oxygen. Limnology and Oceanography: Methods, 4, 7–17. https://doi.org/10.4319/lom.2006.4.7.Google Scholar
- Weilheim, WTW GmbH & Co. (2002). KG Operating Manual, CellOx 325 Dissolved oxygen sensor. Available at: http://www.globalw.com/downloads/WQ/cellox325.pdf.
- YSI. (n.d.). The dissolved oxygen handbook: a practical guide to dissolved oxygen measurements. Available at: http://www.vanwalt.com/pdf/information-sheets/Dissolved-Oxygen-Handbook.pdf. Accessed May 6, 2017.