Publication: Magyar Közlöny
Issue: MK-2003-40 (Year: 2003, Number: 40)
Era: 1990-2004
Section: a 23/2003. (IV. 24.) GKM rendelethez*
Paragraph Index: 420

c) Sound signal intensity and range of audibility A whistle fitted in a vessel shall provide, in the direction of maximum intensity of the whistle and at a distance of 1 metre from it, a sound pressure level in at least one 1/3rd-octave band within the range of frequencies 180—700 Hz (+ /—1 per cent) of not less than the appropriate figure given in the table below. Length of vessel in metres 1/3rd-octave band level at 1 metre in dB referred to 2 × 10—5 N/m2 Audibility range in nautical miles 200 or more 75 but less than 200 1.5 20 but less than 75 Less than 20 0.5 The range of audibility in the table above is for information and is approximately the range at which a whistle may be heard on its forward axis with 90 per cent probability in conditions of still air on board a vessel having average background noise level at the listening posts (taken to be 68 dB in the octave band centred on 250 Hz and 63 dB in the octave band centred on 500 Hz). In practice the range at which a whistle may be heard is extremely variable and depends critically on weather conditions; the values given can be regarded as typical but under conditions of strong wind or high ambient noise level at the listening post the range may be much reduced. 2003/40. szám

Source: https://magyarkozlony.hu/hivatalos-lapok/2e72167675ab9de53a766f2e8ff24eebb8b45c9c/dokumentumok/3fc892723f784b7239921e296e1ba2f32c28559e/letoltes