Uses and Industrial Applications of Colored LED Lights|
Article - January 31, 2016 By LarsonElectronics.com
Uses and Industrial Applications of Colored LED Lights
LEDs are capable of producing an array of colors using RGB diodes. Individually, these colors have very specific industrial applications. From promoting sleep to enhancing night vision, it is vital to understand how colored LEDs are being used by professionals today. For industrial lighting manufacturers, choosing the right color of light may enhance the features and effectiveness of their offerings, resulting in higher consumer adoption rates.
Below elaborates on the myriad of applications one may encounter when using colored LEDs in professional, commercial and industrial environments.
In the military sector, blue LEDs may be used to support map reading in dark locations. Initially, red light is used to pinpoint one’s route on the map. Afterwards, blue LEDs are applied to confirm elevation changes on the route. The change in color is a crucial step to tactical map reading, because blue light allows an individual to see red markings on the map. Red light makes orange, brown and yellow colors difficult to detect. This is also applicable in the marine sector, when reading nautical charts. For divers and marine biologists, blue light supersedes the capabilities of UV light for underwater fluorescence.
Blue LEDs may also be used by military investigators and medics to accentuate the properties of blood and other liquids, such as bodily fluids, in a crime scene. In outdoor excursions, blue LEDs may be utilized to penetrate light fog, though it is important to consider that this color of light is not effective against thick fog.
The medical industry has specific uses for blue LEDs. It is a vital tool for treating Seasonal Affective Disorder (SAD), also known as winter depression. This condition affects over three million Americans per year and is common in areas that experience long, dark winters. The lack of light amplifies one’s depressive and emotional tendencies, causing fatigue and social withdrawal. Exposing patients to blue LEDs reverses this effect, because it mimics clear sky, daylight conditions. This revitalizes the patient receiving treatment, causing the individual to feel more alert and aware.
The light’s ability to keep nearby individuals productive is also applicable in industrial warehouses and manufacturing facilities. In particular, the luminaries can be found on forklifts, where they serve as early warning notification lights. This application keeps workers alert and safe during operations.
Red LEDs have unique applications in astrology and military sectors. They are known for preserving night vision in dark locations. Briefly exposing one’s eyes to bright light rapidly hampers dark sensitivity. When this happens, individuals must wait more than 30 minutes to re-acclimate themselves to their surroundings. Using red LEDs greatly minimizes this occurrence, allowing individuals to view objects in the dark without desensitizing their vision. For astronomers, this is applicable when viewing stars in remote, dark locations. In the military, the use of red LEDs is applied during strategic nighttime attacks. Using red light also decreases risks associated with detection (blackout mode). In the dark, red LEDs help improve dust detection and visual capabilities.
In aviation and marine sectors, red LEDs are applied to various parts of the vessel or aircraft for easy detection. On airplanes, they can be found on the left or port side of the unit. Green light is used on the right side. In the marine sector, red LEDs are used on top surfaces of buoys. On boats, red lights, which are commonly associated with warnings and emergencies, are located on the left or port side with an arc coverage of 112.5 degrees. Ships may also use red-white-red flashes to warn nearby ships that they are hosting nearby (live) diving sessions.
According to the Federal Aviation Administration (FAA), construction sites that use large cranes must apply red LEDs at 300 meters (low intensity) and 350 meters (medium intensity), which serve as early notification signals for low-flying aircrafts.
In the medical sector, red LEDs are used to support light therapy against the following conditions: acne, sun damage, hair loss, bruises and chronic pain. It can also be applied as a natural sleep aid for individuals who are having a difficult time falling asleep at night. Exposure to red light initiates the creation of melatonin, a hormone responsible for promoting rest. On the opposite end of the spectrum (literally), blue light disrupts the production of melatonin and is known for contributing to alertness.
To promote stealth, nocturnal hunters may rely on red LEDs to detect wild pigs, coyotes and other varmints. For such animals, red light is almost invisible. In order to capitalize on this practice, hunters must ensure that the light is only directed at the creature before the kill shot. It is important to consider that some individuals have reported that red light spooks animals. Though it is not clear whether there are other contributing factors to this occurrence, such as scent, noise and external disturbances.
Green and red LEDs have similar uses in the military sector. Green lights can be used to preserve night vision and is easily detectable from a distance (human eyes are sensitive to green light). This is useful when applied to low-key lighting on military bases and camps. As mentioned earlier, green LEDs may also be applied to aircrafts and ships on the opposite side of red LEDs.
Perhaps the most interesting application of green LEDs includes heart rate detection features in smartwatches. Human blood absorbs green light (while reflecting the color red). Smartwatches, like the Apple Watch, capitalize on this property by coupling green LEDs with powerful photodiodes. During operation, the device flashes the light numerous times on the user’s wrist. Most smartwatches also use infrared signaling to ensure that heart rate readings are accurate. Depending on the user’s activity, a device can switch between the two options in real-time.
Green LED spotlights and underwater lights are extremely helpful during nighttime fishing. They can be used to attract zooplankton, which triggers a feeding frenzy around the light, eventually luring larger fish close to the boat. In order to get the most out of this practice, individuals may utilize several types of green luminaries, such as floating lights and submersible fishing fixtures with a weight clip. In the commercial fishing sector, a green-white signal suggests that a fishing vessel is trawling.
Amber and yellow LEDs are widely known for applications in warning lights for non-emergency cars, such as tow trucks, security vessels and construction vehicles. They are also used to support construction signs, such as notifications of road repairs or closed paths. Such applications are uncommon for police and ambulance operations. Unlike red LEDs, which are closely associated with emergencies, yellow LEDs signal caution. In foggy conditions, amber LEDs may help increase visibility and reduce glare.
In the marine sector, yellow LEDs indicate that a lead boat is towing a vessel. This prevents other boats from running in between the two ships and potentially tangling or seriously damaging the vessels.
In forensics, yellow light may be used to detect the following: hair (treated, red or blonde), shoeprints, blood (untreated) and bite marks. Farmers also rely on yellow LEDs to deter the destructive behavior of pests, including moths. When exposed to yellow light at night, such creatures revert to their daytime behavior. Without the lights, moths will attempt to suck juice out of fruits and mate prolifically. Yellow LEDs do not affect the natural growth of nearby plants.
Orange LEDs have a plethora of applications in forensic investigations. They can be used to detect the following components: bones, teeth, fingernails and gunshot residue. In some cases, orange lights are utilized for cautionary signaling, in the same way amber or yellow LEDs are used.
Lastly, purple LEDs are mostly found in indoor growing houses. Out of all the visible lights in the spectrum, purple contains the most energy. Plants don’t have a color preference when it comes to light (except for green, which is ineffective because the pigment of chlorophyll is green). During indoor cultivation, different lights may be applied, depending on the type of plants and their growing stages. For example, blue light is suitable for vegetative, leafy plants. A combination of red and blue LEDs is ideal for flowering plants.