ISO 14859-2012 pdf free download

ISO 14859-2012 pdf free download.Ships and marine technology — Sound reception systems
Navires et technologie maritime — Systèmes de reception sonore.
The test signal shall be a 3 second test tone. The SPL and frequency characteristics of the test signal/source received at the microphones shall be equivalent to the intensity and range of audibility of the sources stated in Table 86.05 of COLREG 72. Annex Ill, Technical Details of Sound Signal Appliances. Frequency-dependent damping of the signal (according to its range of audibility) shall be taken into account as described in ISO 9613-1 (air temperature 10°, 90 % humidity). This can be achieved by pre-processed signals or appropriate filtering technology. The test signals representing the different ship classes may be synthesized using digitized waveform or a set of discrete frequencies.
A noise (1/f2) with 57 cIB (SPL) octave band level at 1 kHz. measured at the centre of the sound reception system (Note: sound reception system removed during calibration measurement), shall be used for all lab testing. Reproduction of a test signal should be introduced by the noise signal of minimum 10 s length to allow the detection algorithm to adapt to the noise signal. Noise shall be reproduced from at least three different directions. The minimum distance of the loudspeaker which reproduces the test signal to the microphones shall be at least four times larger than the largest dimension of the sound reception system (Dmax in Figure B.1). Non-linear distortion of the loudspeaker used for reproducing the test signal must be below -40 dB in the frequency range from 70 Hz to 2 100 Hz.
5.3.1 General
Conduct an omni-directional test to ensure that sounds are received from all directions (360° at either 22.5° or 30° intervals) over the frequency band of 70 Hz to 2 100 Hz within —3 dB. The system and visual indicator shall be tested using an acoustic source at 22,5° or 30° intervals starting at 0°.
5.3.2 DIrectionality and audio persistence
LIMO MSC.86(70) Annex 1. 3.3J Move test signal source or the unit under test throughout 360° and confirm that the display correctly identifies at minimum port)starboard and fore/aft directionality. Cause the test signal to appear at 3 s intervals throughout 3600 at 22,5° or 30° intervals and confirm that the display gives a visual indication of the incoming signals for at least 35 with the appropriate port/starboard and fore/aft directionality.
6 Installation performance tests
6.1 Microphone Installation
The microphones shall be externally installed in such a way that they are as tar from noise and mechanical vibrations sources In the ship as Is reasonably practicable. Microphones shall be installed to minimize wind- induced noise. Confirm microphone location by inspection.
6.2 Bridge equipment installation
[IMO MSC.86(70), Annex 1,4.2] The display should be installed so that it is visible at least from the conning position. Confirm display location by inspection.ISO 14859-2012 pdf free download.