Catalogues - acoustic-lumimous

Catalogue Acoustic lumimous

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GUIDELINES FOR INTERPRETATION AND APPLICATION OF THE NORMS - LUMINOUS LINE

Visual warning signals establish a code communication through two variables, i.e. different degrees of brightness and the use of different colours. Through these features the operator receives information.

According to different characteristics we can classify various types of luminous signals in the Sirena product range:

• The degree of brightness changes according to:

- the distance between the luminous point and the observer

- the different type of diffuser lens used

- the colour of the dome selected.

• The light intensity of Sirena warning signals is measured in Cd (p) in a photometric chamber. The Cd (p) represents a peak luminous intensity using a clear dome. To establish the actual output when installing the beacon, the distance and the colour of the dome must be taken into consideration. For example, if the viewing distance is doubled, the light intensity observed is reduced by a quarter and if the distance is quadrupled the light intensity is reduced by a sixteenth. Furthermore, the Cd (p) rate is measured using a clear dome that allows 100% brightness. The brightness is reduced dependant upon the colour of the dome, for example:

By using the following formula the "LUX" measurement is obtained:

Cd = LUX x DISTANCE²LUX = Cd

DISTANCE²

For example 10.000 Cd = 10.000 LUX at 1 m. = 100 LUX at 10 m.

• The degree of brightness from a continuous light beacon is given by the power of the bulb. The brightness can be increased by using a Fresnel lens.

The flashing light can be obtained in three ways:

- by the on/off cycle of the filament bulb

- through periodic rotation of a parabolic mirror around the axis of a continuously lit bulb

- through the flash of a xenon discharge tube.

Flashing beacons generally take more time to light up the bulb and give a lower degree of brightness. The efficiency of the signal is due to the fact that when the bulb is lit, the whole surface of the beacon is illuminated giving light at 360°.

Rotating beacons have a greater degree of brightness, however, the light intensity at each point of observation is reduced as each point is illuminated only when the mirror rotates in its direction.

Xenon beacons, on the contrary, allow maximum brightness due to the fact that the bulb takes less time to light up. Visibility at 360° is guaranteed and can also be increased by using a Fresnel lens.


		A/⁵ ² ³ ¹ ⁴
Light transmission		100% 95% 70% 30% 17% 12%
Light transmission	1	100% 94% 70% 27% 20% 15%
	i m	100% 93% 70% 23% 24% 25%

• The current standards regarding visual signals used in industrial applications state that warning signals must be five times brighter than the ambient light level. Emergency signals must be ten times brighter than the ambient light level. In order to ensure that the correct beacon is selected the ambient light level must be measured. The ambient light level is measured in LUX and can be easily established by using a "LUXOMETER".