Pipeline inspection pig identification arrangement, in which pig locating takes place by the exchange of acoustic signals between an acoustic unit mounted with the pig and an external acoustic unit

摘要

Arrangement for identifying inspection pigs in a pipeline, comprises at least a unit outside the pipeline with an acoustic transmitter for transmitting an acoustic signal into the pipeline and an acoustic receiver for receiving an acoustic signal back from the pipeline and at least a unit inside the pipeline for transmitting acoustic signals outside the pipeline and receiving acoustic signals from outside the pipeline.