Types of Warning Signals, Visual
Choosing the right visual signal
The most suitable visual warning signal will depend on the type of beacon, the required light output, the viewing distance, the dome colour and the environment in which it will be installed.
Brightness, efficiency, operating life and visibility should all be considered when choosing between rotating, xenon and LED beacons.
Levels of Brightness
Brightness depends upon the type of beacon chosen, the rated power output of the unit i.e. Watts and Joules, the distance that the signal is observed from and the dome colour of the beacon used. In general, if the viewing distance is doubled, the light intensity observed is reduced to a quarter and if the distance is quadrupled the light intensity is reduced to a sixteenth.
Effective Candela
At Moflash, we are committed to providing our customers with the highest quality lighting solutions. One way we do this is by using effective candela to measure the light output of our beacons, rather than peak candela or candela lumen.
The effective candela is a measure of the brightness of a source of light that considers the sensitivity of the human eye to different wavelengths of light. It is therefore a more accurate measure of the actual perceived brightness of a light source than the peak or lumens candela, which do not reflect this sensitivity.
Using effective candela to measure light output is the most appropriate unit for beacons as it provides the most accurate representation of the light emitted by the device. This is important for applications where the visibility of the beacon is critical, such as in emergency situations or industrial applications.
By providing information on effective candela on our data sheets, we aim to provide our customers with the most relevant information when choosing the right beacon for their needs. We truly believe that using effective candela is a key part of our commitment to providing the highest quality lighting solutions to our customers.
Beacon Lens Colours
The intensity of the light can be greatly reduced as it passes through the dome of the beacon. The extent of this reduction is dependent upon:
- The type of light source used i.e. conventional Filament (Incandescent) Bulb, Tungsten Halogen Bulb, Xenon Tube or LED.
- The colour of the beacon lens that is used.
Lens colours available are shown in the below table:
The next table gives an indication of the percentage of light that will pass through the beacon dome for different light sources and dome colours.
| Colour | Filament | Halogen | Xenon |
|---|---|---|---|
| Clear | 100% | 100% | 100% |
| Amber | 70% | 70% | 70% |
| Red | 30% | 27% | 23% |
| Green | 12% | 15% | 25% |
| Blue | 8% | 10% | 13% |
Dome colours convey different messages to the observer:
| RED | Serious Danger – Act now! |
| AMBER | Warning proceed with care |
| GREEN | Ok proceed as normal |
| BLUE | Specific process notice/warning |
Need help selecting the right warning signal?
If you’re unsure which warning signal is suitable for your environment, contact the Moflash team for support with product selection.