Monday, November 18, 2013: An economical micro sensor to monitor ocean acidification in the long run has been attained by a team of scientists and engineers. It is created for measuring pH levels in sea water and was devised by engineers from the National Oceanography Centre in association with oceanographers from University of Southampton Ocean and Earth Science based at the centre.
As cited on theengineer.co.uk, the team carried out tests on the new device on the RRS Discovery and presented their results in Anaytica Chimica Acta. It can be used for on-board analysis of seawater samples with the long-term aim being to further developing the design for it to be deployed for longer, in situ measurements.
Due to the rise in levels of atmospheric carbon dioxide, there is ocean acidification, which is being absorbed by the oceans. Once CO2 is combined with seawater, it forms a mild acid that reduces ocean pH globally and can potentially affect marine ecosystems.
As per Dr Victoire Rérolle, lead author and researcher with NOC’s Sensors group, “We need to monitor seawater pH to a high level of precision and accuracy, and over long periods of time, in order to detect changes in the carbon system.”
Apart from monitoring global change, the sensors can measure more localised human impact. The micro sensors can be used for detecting leakages from carbon capture and storage sites by measuring any proximal fluctuations in pH. The microfluidic chip located inside the sensor offers advantages as it is robust, small, reasonably cheap to produce, and uses small amounts of reagents, a key factor for in situ deployment. The sensor makes use of a dye which changes color with pH. After the dye is added to the sample, the colour is measured using an LED light source and a spectrometer.
