Cost-efficient oceanographic instrument with microfabricated sensors for measuring conductivity, temperature and depth of seawater

Možek, Matej (author), Pečar, Borut (author), Vrtačnik, Danilo (author)

The design, fabrication and characterization of a cost-efficient oceanographic instrument with microfabricated sensors for measuring conductivity, temperature and depth of seawater are presented. Conductivity and temperature sensors were fabricated using MEMS technology, which allows for customized small footprints and low production costs. Dedicated electronics for reading, processing and storing acquired sensor data are described. The developed instrument enables the measurement of seawater conductivity in a range from 4 mS/cm to 70 mS/cm. The conductivity measurement is temperature-compensated in the range from 2 °C to 40 °C, with an accuracy of ±0.1 mS/cm. The temperature sensor’s stability is 0.025 °C. The depth/pressure measurement range is up to 2000 m/200 bar, with a resolution of 0.1 bar. Temperature and conductivity sensor performance was assessed using laboratory equipment and designed electronics. The conductivity sensor was temperature-compensated to 0.01 mS/cm. The conductivity sensor electrode corrosion effect is presented below and was eliminated through adaptation of a signal acquisition circuit. Custom software was developed for monitoring critical conductivity sensor parameters (currents, voltages). A variation of 0.4% between cell conductance currents and voltages was established as a criterion for stable conductivity sensor operation.

• Language: English
• Keywords: microfabrication, MEMS, conductivity, temperature, depth, NAUTILOS, marine measurement
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 28 str.
• Numbering: Vol. 24, iss. 12, [article no.] 3940
• PID: 20.500.12556/RUL-158886
• UDC: 621.3.049.77
• ISSN on article: 1424-8220
• DOI: 10.3390/s24123940
• COBISS.SI-ID: 199466755
• Publication date in RUL: 21.06.2024

Record is a part of a journal

• Title: Sensors
• Shortened title: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• COBISS.SI-ID: 10176278

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: mikroobdelava, MEMS, prevodnost, temperatura, globina, NAUTILOS, meritve morja

Projects

• Funder: EC - European Commission
• Project number: 101000825
• Name: New Approach to Underwater Technologies for Innovative, Low-cost Ocean obServation
• Acronym: NAUTILOS