U.S. Patent No. 7,228,900 - System And Method For Determining Downhole Conditions (Jun. 12, 2007)

The present invention provides a system for determining downhole conditions including a time domain reflectometer (172) that is operable to generate a transmission signal and receive a reflected signal. A tubular (192) is positioned downhole in a downhole medium (214, 216, 218, 220, 222) and a waveguide (186), which is in electrical communication with the time domain reflectometer (172), is operably contacting the downhole (214, 216, 218, 220, 222). The waveguide (186) is operable to propagate the transmission signal and operable to propagate the reflected signal that is generated responsive to an electromagnetic property of the downhole medium (214, 216, 218, 220, 222).