Efficient experimental procedure for antenna calibration in plastic/concrete/metallic conduits

The paper presents the design and construction of a test bench for the analysis and certification of antennas inside conduits filled with liquids. The proposed infrastructure can be efficiently applied to the calibration of the electromagnetic front-end of nodes belonging to wireless sensor networks deployed inside conduits used to transport and/or distribute dissipative liquids. The design has involved the classification of a large variety of pipelines, among which three different samples have been selected. The pipeline has consequently been configured in order to host fixed or mobile antennas, which can be wired towards the external part of the conduit, to facilitate their connection to a network analyser. The speed and pressure of the liquid, as well as the speed of the antenna, can be controlled remotely. A de-embedding procedure has been introduced, in order to characterize the reflection loss at the antenna terminals. Finally, in case of metallic pipelines, a procedure has been introduced to test the attenuation along the longitudinal direction of the conduit.