A Unique Data Acquisition System For Electrical Resistance Tomography

Unique capabilities are needed in instrumentation used<br>for acquiring data to do electrical resistance tomography (ERT) . A<br>data acquisition system is described which has a good combination of<br>the required capabilities and yet is rugged and user friendly. The<br>system has a multichannel detector for high data rates, can operate<br>over a wide range of load conditions, and will measure both inphase<br>and quadrature resistance at frequencies between 0.0007 Hz and 8<br>kHz. The system has been used in both the field and laboratory to<br>collect data with a typical accuracy between 1 and 10%.