What are ultraviolet lights good for?

Posted by Carl Fyffe on

We often get emails asking if we sell black lights. The emails are typically from teenagers looking to light up the posters on their wall but sometimes it's from businesses trying to protect their enterprise. We are also contacted by several different professions looking for a black light for work.

First, what is a black light? A black light is actually a small segment of ultraviolet lights. Ultraviolet lights are lights that shine from the 10-400nm wavelength. Black lights in particular have a wavelength between 315-400nm. There are a variety of ways to create this effect including using special glass or actually emitting these wave lengths from an LED. Ultraviolet is mostly invisible to the naked eye because the human eye can not see below 400nm.

Ultraviolet electromagnetic spectrum

Ultraviolet light has many more purposes other than creating cool colors on your favorite band's posters. These range from forensic investigations to sports fishing.

Bodily fluids such as saliva, urine and semen fluoresce under an ultraviolet light. There are several professions that use ultraviolet flashlights to help them do their job based on this fact. Hotel staffs have started using ultraviolet flashlights to ensure that they have properly cleaned a room. Each attendant checks each section of the room and inspects it to ensure that the next guest has a clean environment to rest. Any time the light causes something to glow green they know they have missed a spot and clean it up immediately.

Another profession that uses ultraviolet flashlights day-to-day to detect saliva, urine and semen are forensic detectives. The ultraviolet light allows forensic detectives to see where a mess has been cleaned up trying to hide evidence at a crime scene. While the mess might seem clean to the naked eye, these fluids leave a residue that is not easily removed. Pepper spray companies have also started adding extra chemicals that will fluoresce under ultraviolet light. Again, these chemicals are not easily removed, so if you are in a scuffle and run away, detectives can use an ultraviolet light to prove that you were at the scene. If you are naughty your local CSI will be able to figure it out.

Sometimes you need to be your own CSI unit. You know your pet has urinated in your house but you can't seem to figure out where. An ultraviolet light is great for helping pet owners track down where their animals have been urinating so that it can be cleaned up.

Nightclubs and other establishments which take cash also require ultraviolet lights to ensure the currency they are receiving is legitimate. United States currency uses strips of precisely placed strips of plastic in their bills. These plastic strips will fluoresce under a black light. Each bill fluoresces a different color. This means counterfeiters must get the location and color of the strip correct to be able to pass off fake bills. The U.S. government also use paper that does not fluoresce, so if your bill lights up in the white areas, you have found a counterfeit bill. Even credit card companies have started using ultraviolet lights to determine if the cards are legitimate. They load the cards with holograms that only show up under ultraviolet light next to the hologram that is visible in visible light.

$20 under UV light

Many states are using anti-counterfeiting systems to ensure their state driver's licenses are not fake. This discourages teens from using fake IDs to gain access to environments where they are not allowed. But forensics and documents are not the only use for ultraviolet lights.

Many animals see in the ultraviolet spectrum. Fish are especially attracted to ultraviolet light. Sports fish like bass and trout are especially attracted to ultraviolet light because their prey fluoresce when exposed ultraviolet light. Tackle companies have started offering lures with fluorescent bodies in an effort to attract more fish to the bait. Field and Stream found that this is a legitimate way to catch more fish, especially as the sun goes down.

Glowing Scorpion

Fish aren't the only animals that fluoresce under ultraviolet light. Scorpions’ exoskeletons have a protein called beta-carboline which causes them to fluoresce under ultraviolet light. Not only are scorpions scary looking, but they glow in the dark too. We sell many UV lights to people that live in Arizona where scorpions are considered pests. The best way to find scorpions is using a UV light.

If any of these professions or needs match you, then you will be interested in one of our flashlights. Whether you are a detective of hotels, forensics or pets, we can help you find the best UV flashlight for your needs.

While we have multiple ultraviolet lights available, two really stand out. Inova's X5-UV is more casual and is better for those looking for a compact light in close-quarter applications such as checking ID cards, currency or hotel rooms. Nitecore's CU6 on the other hand is a professional grade, high-end flashlight purpose built for hunters, detectives, and forensic specialists. The CU6 is built for the outdoors where longer distances are needed, tracking bleeding prey.

Nitecore CU6

The CU6 has four LEDs. The first LED is an ultraviolet LED that has a 365nm wavelength light. This light is perfect for seeing blood on the ground when you are tracking your prey or tracking the fleeing suspect that is trying to get away. This light is also good for the forensic specialists and detectives that are examining a crime scene. It has the white light when you need to be able to see in those dark places and the UV light for detecting messes that have been cleaned up.

The second LED is white and has five modes: Moonlight, Low, Medium, High and Turbo. Moonlight mode is 1 lumen and will last for approximately 440 hours. This is perfect for those early mornings when you are getting ready to go hunting but you don't want to wake your spouse. Up from there is Low which is 25 lumens and will last for about 43 hours and Medium which will last for 7 hours and give you 160 lumens. For those times when you need some serious light is High which puts out 280 lumens for about 3 hours and 30 minutes and Turbo which kicks out 440 lumens for an hour and 45 minutes. Nitecore's CU6 also has location beacon, SOS and strobe modes for when the situation does not go as planned.

Last, there are two multi-colored LEDs which lets the CU6 produce red, green and blue light. Red, green and blue lights are great for maintaining night vision. Red is best at preserving night vision. You can use the red light to find what you are looking for and when the light goes out you will not have lost a majority of your night vision like you would with a white light. Green light allows you to see more detail in your surroundings. Green is great for reading a map or anything that requires crisp and precise visibility. It still affects your night vision but not as much as white. Blue is close to ultraviolet, so some bodily fluids stand out against blue. Blood specifically stands out when being lit by a blue light. If you would like to see the effects of different colored lights you should check out our article on which color of light is best for reading. There is also a red/blue signal mode which is good for warning off traffic if the need arises.

The CU6 has a tail switch to turn the flashlight on and off, and two side switches for switching colors. One side switch is dedicated to the white LED and switches the brightness. The second side switch loops through the color LEDs and the ultraviolet LED.

This light is built to be mounted on a weapon. The 1" diameter body will fit in most weapon mounts. The battery chamber, which will hold 1 18650 lithium-ion battery or 2 CR123A batteries, is spring loaded to ensure your light keeps working even after firing your weapon. Nitecore also offers the RSW1 pressure switch which allows you to easily use the light while it is mounted to your weapon.

Nitecore's CU6 is a high quality light that is great for environments that require a sturdy build that won't break when presented with rough situations. The CU6 is the best UV light available today. However, if you don't need all of the features of the CU6, you just need a reliable UV light that will stay indoors, then you will be interested in the X5-UV.

Inova's X5-UV is an excellent ultraviolet flashlight that is single purpose, quick access to UV. This light is perfect for bouncers checking ID at clubs and bars, or cash registers at casinos, clubs and bars. At $44.99 it is less expensive than the CU6 by $60 but the quality is still there. You are saving by having a single purpose light.

The X5-UV has five ultraviolet LEDs that produces light at 365-400nm wavelengths. This is right in the sweet spot of black light. The light has two modes. It will run on high for 17 hours and 30 minutes and will run on low for 85 hours. The light is turned on and off by a tail switch which also has a temporary on mode. You can twist the cap to set which mode is used for the temporary mode. The X5-UV is powered by 2 CR123A batteries which are included with your purchase.

The X5-UV is an easy to use, single purpose flashlight that really gets the job done.

The last ultraviolet light that we wanted to show is more of a do it yourself project than a full package you can purchase. If you ride at night just being seen is very important. Making other drivers aware of your presence greatly increases your safety while riding at night. This project utilizes UV's unique ability to cause materials to fluoresce to increase the visibility of your bike at night. This intrepid DIYer cut out some plastic strips and covered them with a fluorescent paint. He then attaches them to the spokes of his bike creating a circle of plastic near the hub of his wheels. He then mounts UV lights to his forks and lines them up with the plastic strips. When the lights are on and the wheels are spinning those plastic strips light up. Honestly it makes your bike look like it came straight out of the movie Tron. This project gives you a fantastic side profile in the dark, increasing your safety and adding just a little bit of cool to your ride. Here's a video of how to make your own ultraviolet wheel caps for your bicycle and what it looks like on the road.

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