Bids Are Invited For Electrical Resistivity Tomography System For Time-Lapse Monitoring

Electrical Resistivity Tomography System For Time-Lapse Monitoring.The Edwards Aquifer Authority (Eaa) Is Interested In Purchasing A Surface-Based System For Generating Electrical Resistivity Tomography (Ert) Images Of The Deep Vadose Zone For Hydrogeological Investigations. The Ert System Will Be Deployed Primarily For Time-Lapse Monitoring Of Changes In Vadose Zone Water Storage In Soil And Epikarst In The Upper ~150 Feet Of The Subsurface At Various Research Sites In The Edwards Aquifer Region In Central Texas. Some Sites Will Be Outfitted With Permanently Buried Cables And Electrodes For High-Frequency (E.G., Sub-Daily) Time-Lapse Ert Imaging. Other Sites Will Be Imaged Intermittently (E.G., Bi-Weekly) With Portable Equipment.The Ert System Must Be Compatible With Both Applications.22034-Logging Devices, Electronic (Long-Range Data Collection And Recording For Use At A Remote Location)49507-Agricultural Science Equipment: Diffusive Resistance Meters, Leaf Porometers And Water Potential Measuring Equipment, Seed Counters And Germinators, Soil Sterilizers, Etc.22030-Indicating And Recording Instruments, Equipment And Accessories (Not Otherwise Classified)49544-Geology Equipment And Supplies