I57 L3 and L4 Rosettes Retrofitted

October, 2009: In October, Michael and Clint replaced the L3 and L4 rosettes at I57US with new pipes that are more corrosion resistant. The inlets were also replaced. The data now look to be much quieter.

I57 Noise Floor Issues Resolved

September, 2009: In September, Michael and Clint changed the power supplies of the MB2000 sensors. They inserted Newmar 12 V DC-DC power converters (also called isolators) in between the power sources and the MB2000's internal switching power supplies. These converters lowered the self noise of the MB2000 sensors back to their pre-Geotech digitizer levels (pre-2005).