Depending on their design, electrodes are used for measurements of i.a. Redox potential, oxygen, sulfide or pH in the water and sediment. Oxygen electrodes in particular "consume" some oxygen during the measurement process. It is therefore an advantage for fast, high-resolution and precise measurements to use needle electrodes with a rapid response time and a low oxygen consumption. In addition to robust metal electrodes, glass micro-electrodes are used (especially suited for laboratory measurements). Because of the extreme fragility of the thin glass micro-electrode tips, these electrodes cannot be used for measurements in every type of sediment sample. The encounter with gravel, coarse sand or shell fragments is not recommended...
Glass electrode tip: the top one is new, the bottom one broken
For high-resolution profiles, a tripod and a micro-manipulator are also needed, i.e. for an exact positioning in steps on the scale of micrometres.
Experimental set-up for near-shore measurements