Instruments and Methods Mineral Deposition in Current Meter Bearings.

摘要

Carbonate deposits (siderite, aragonite and calcite) have been identified within current meter bearings. These deposits were observed to inhibit and even prevent the response of sensors mounted on the bearings. The mechanism of precipitation of these minerals is described, with partiuclar reference to the increased reaction rate found when an electrical path is permitted between a sacrificial anode and a stainless steel bearing (which becomes a cathodic crevice). Future deployments at sea of instruments with cathodic crevices should be carefully evaluated in light of the deposition mechanism described. (Author)