According to requirements of Maritime Administrations, there is a necessity for next inspections of EPIRBs after receiving of type approval. The problem is a complexity of the basic beacon signal parameters, which could not be measured with the simplified handheld testers. The most complicated for measuring and the most important for reliable communication to satellite and accurate position calculation are the frequency stability and phase modulation parameters. As a rule they require specially designed equipment in addition to standard measurement instruments (spectrum analyzer, frequency counter, etc.) which are not usually available on a ship board.

Beacon tester BT611 allows to perform not only control tests, but comparing evaluation of different EPIRBs parameters, too.