Acoustic transmitter and method for underwater pipeline inspection gauges

摘要

A multiple frequency ping transmitter which can be carried by a pig which is used in an underwater pipeline. The ping transmitter produces a ping chord which includes a plurality of different tone frequencies which are simultaneously transmitted in the ping chord. Procedures are also provided wherein the multiple frequency ping transmitter is used in a system and method for located a pig which is stuck in the underwater pipeline or for determining the relative velocity of a moving pig.

主权项

1. A ping transmitter comprising: a housing and
a free-floating ring transducer projecting from said housing, wherein said free-floating ring transducer transmits a ping chord comprised of a plurality of different frequencies, said plurality of different frequencies being transmitted simultaneously in said ping chord and said plurality of different frequencies comprising at least 12 different frequencies.