Coordinated Alerts for Optimal Response

For an alert to prompt the correct response, seamless coordination between people and technology is essential. Visual signals not only serve as warnings in hazardous situations but also ensure smooth operations through distinct colour patterns.

Colour Coding for Clarity

Colours guide the way, much like traffic lights: green indicates that everything is OK, yellow signals caution and may require further action, and red warns of a critical status. Users can instantly recognize issues with production machinery or when doors, gates, chambers, vehicles, or forklifts are not functioning properly. Visual alerts are particularly vital in high-risk environments, such as during a gas leak at an oil refinery or fuel depot, where lives are at immediate risk. Visual signals have the advantage of being seen by specific groups or large numbers of people simultaneously, whether in traffic or around industrial machinery.

Signalling Ranges

Visual signals—whether generated by LEDs, incandescent lamps, halogen lamps, or gas-discharge lamps (xenon)—are widely used across industries. These signals must be carefully tailored to their specific application. The challenge is ensuring that signals are visible both day and night without causing glare or overwhelming viewers.

Luminous intensity (measured in candela, cd) is crucial for selecting the right type of signal for a specific application. It is calculated based on the emitted luminous flux (in lumens, lm) within a defined solid angle. For signalling technology, only the portion of the luminous flux emitted in a specific direction is considered. For example, the luminous flux of a standard candle, at 12.566 lumens divided by 4π steradians, results in a luminous intensity of 1 cd.

The effective luminous intensity is then determined to calculate the warning and information ranges of signals. While different methods exist for calculating signal range, the Blondel-Rey equation is the most commonly used. This equation helps calculate the effective luminous intensity (Ie), which forms the basis for determining signal ranges. However, the emitted radiation energy (measured in joules) does not directly correlate with signal range due to variations in radiating characteristics and light source design.

Flashing Signals: More Effective Alerts

Flashing signals are often used as visual alerts because moving light is more noticeable than static light. R. STAHL collaborated with the Technical University of Ilmenau to study which signal and flashing patterns are most effective. Research into signal perception has explored various blinking/flashing patterns to achieve optimal visibility and impact, going beyond the theoretical calculations of signal ranges.

LED Technology: A Game Changer

Signalling technologies have evolved significantly over the years, from candles and light bulbs to halogen lamps and the now widespread use of gas-discharge lamps with noble gas (usually xenon). Today, state-of-the-art LEDs are increasingly used for providing primary status information (steady light) as well as for sending warning and alert notifications. LEDs are becoming more prominent in many industrial applications due to their longer service life, durability, even light emission, and variable brightness and colour rendering. However, they do not yet match the high peak cd values of xenon flashing units. To address this, signal patterns can be designed to be more flexible and extended, an area R. STAHL has explored with partners and research institutes.

The major advantage of robust LED fittings is their flexibility. For example, the YODALEX/2 LED light fitting from R. STAHL, launched last year, offers a wide range of preconfigured visual signal patterns, including continuous light, blinking light, flashing light, and rotating light. It also comes with seven lens colours, four output levels, and four different light modes. This versatility allows operators to quickly adapt the light fitting to their specific operating environment. Additionally, the energy-saving benefits of LEDs should not be overlooked.

In Summary

Fast and clear information can be a matter of life and death, especially in hazardous areas. In production environments, clear signalling ensures safe processes and optimized manufacturing. R. STAHL provides expert guidance in choosing the right signalling technology for both safety and operational efficiency, ensuring that signals are perfectly tailored to the operating conditions.

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