Water Pressure Measurement with Time Domain Reflectometry Cables
Attributes of the remote measurement of piezometric water pressure and water level with time domain reflectometry (TDR) techniques are investigated. The evaluation includes a two-wire system for unusually small riser tubes as well as parallel wire and air-filled or hollow coaxial cable for typical installations. Comparison of TDR cable and commercial pressure transducer technology shows coaxial cable TDR systems with distance crimps capable of equaling and exceeding the resolution of pressure transducers. Crimps provide permanent distance markers that allow the TDR system to be self-calibrating.