Sice Fog horn test in the anechoic room of Ferrara University.
On 27/01/2015 Sice has carried out a new test to measure the sound pressure level on our Fog Horns model Sice NV-V3 & Sice NV-V1. The test has been carried out in the anechoic room at laboratories of the Department of Engineering in the Scientific-Technological Campus of the University of Ferrara. This anechoic room has been selected by Sice because its dimensions have allowed to carry out the measure at minimum required distance (even higher) in the reference IALA recommendations.
The NV-V3 Fog Horn is composed of 3 emitters overlapping that form a soundtrack and it must to guarantee a sound range of 2 Nm. The Fog Horn NV-V1 is composed of only 1 emitter that it must to guarantee a sound range equal or superior of 1/2 Nm.
The test has carried out in conformity to the follow rules/recommendations:
• IALA Recommendation E-109 “On The Calculation Of The Range Of A Sound Signal”, Edition 1 – May 1998.
• IALA Guideline No. 1090 “On The Use of Audible Signals”, Edition 1 – December 2012.
• UNI EN ISO 3745:2004, Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pressure — Precision methods for anechoic rooms and hemi-anechoic rooms
The test result showed the high efficiency of Sice Fog Horns and has been confirmed to be conform at IALA recommendation ensuring the sound pressure level required with a very low electric power consumption, these are the results:
• Fog horn NV-V1: Minimum sound pressure level measured 125dB @ 1m, electrical power consumption <25W (including the oscillator circuit), with a power supply of 24Vdc.
• Fog horn NV-V3: Minimum sound pressure level measured 134dB @ 1m (max 136dB @ 1m), electrical power consumption <75W (including the oscillator circuit), with a power supply of 24Vdc.
• Working frequency in the range between 826-832Hz
We noted that the IALA Guideline No. 1090, tabel 2 “usual range”, for the frequency range of 800Hz, requires the following value:
• Level of sound pressure for a range of ½ Nautical mile : min. 112dB @ 1m
• Level of sound pressure for a range of 2 Nautical mile : min. 134dB @ 1m