pneumatic horn / for ships >200 m
for ships >200 m
Nowadays, each vessel from 12 metres and more (length over all)
must be equipped with sound signal appliances which are type
approved according to the IMO regulations. Hence, one part of
the responsibility is the manufacturer's, but still one important
part is the shipowner's regarding the choice of appropriate equipment
for the vessel in question, the installation and use.
The reason behind the stipulated use of 1/3 octave band filters
when measuring is connected to the theory of the hearing sense.
A "complex" sound like that from TYFON® or SUPERTYFON
consists of several harmonic com-ponents. Consequently, the
total SPL value is considerably higher than the measured (stipulated)
1/3 octave value.