What is 365nm UV Light and What is It Used for?

What is 365nm UV Light and What is It Used for?

10 Mar, 2023

365nm UV light (also referred to as "long wave UV light", "black light") is a type of near-ultraviolet light that is invisible to the naked eye. It is often used in special lighting applications and is particularly well-suited for fluorescence and bacterial detection. With a longer wavelength than the short-wave visible light, it is able to penetrate substances more deeply and thus provide a deeper illumination.


Benefits of 365nm UV Light

 Because of the nature of the longer wavelength, substances which may be difficult to detect with a shorter wavelength of visible light can be easily revealed with 365nm UV light. This means that it can be used to reveal evidence of past events which may have otherwise been impossible to detect. Examples include traces of fingerprints on surfaces and documents, biological matter like saliva, and other types of evidence that are often seen in criminal investigations.

It can also be used in science and industry, such as in counterfeit detection, material testing, and medical diagnostics. 365nm UV light is used to detect minute differences in materials which could not be revealed through visible light. Because of its ability to penetrate deeply, it is also useful for studying the structure of objects or materials which may require very detailed imaging or measuring.


What is It Used For?

Medical professionals and domestic use 365nm UV light to look for evidence of disease, fungi, and bacteria which can be illuminated under this wavelength. In some cases, it can be used to detect the presence of harmful molds which cannot be seen with the naked eye.

It also helps prevent these organisms from growing on the surface.

When you expose bacteria to 365 nanometer light, it causes damage to the DNA inside the cells. This damages the DNA, which prevents cells from functioning properly. Eventually, the cells die and the bacteria no longer exist.

When you wash vegetables in water, use 365nm to kill bacteria in the water system.

When you are not sure whether the food has gone bad, you can see the difference in the food by irradiating with 365nm UV light.

Other uses:

1. It is used by forensic scientists and law enforcement personnel to detect evidence of past events which can't be seen using visible light.

2. It is also used in counterfeit detection, such as in currency and document authentication, as well as in material testing and research.

3. Manufacturers use 365nm UV light to examine materials for defects, irregularities, or inconsistencies that may be difficult to detect with visible light.

4. 365nm UV light is also used for gemstone grading and analysis.

5. 365nm can cure resins and harden plastics


Black Light vs UV Light

Blacklight, also known as long-wave ultraviolet light, has a wavelength between 400 and 315 nanometers (nm). It is a type of ultraviolet light (UVA light) that emits ultraviolet radiation in the UVA band. These ultraviolet rays have low energy and long wavelengths, and the ultraviolet radiation (radiation to the human body) is also minimal.

Look at the international standards for the division of ultraviolet bands (source: Wiki)




Photon energy
(eV, aJ)

Notes/alternative names

Ultraviolet A




Long-wave UV, blacklight, not absorbed by the ozone layer: soft UV.

Ultraviolet B




Medium-wave UV, mostly absorbed by the ozone layer: intermediate UV; Dorno radiation.

Ultraviolet C




Short-wave UV, germicidal UV, ionizing radiation at shorter wavelengths, completely absorbed by the ozone layer and atmosphere: hard UV.

Near ultraviolet




Visible to birds, insects, and fish.

Middle ultraviolet




Far ultraviolet




Ionizing radiation at shorter wavelengths.

Vacuum ultraviolet




Strongly absorbed by atmospheric oxygen, though 150–200 nm wavelengths can propagate through nitrogen.

From the above table, you can see that ultraviolet rays are divided into different types of ultraviolet rays according to their wavelengths, including UVA, UVB, UVC, near ultraviolet, and far ultraviolet.

Therefore black light is used in many of the same applications as 365nm UV light, such as counterfeit detection and fluorescence.


Benefits of Black Light

Black light has several benefits over other types of light.

One benefit is that it is able to penetrate deeper than visible light and thus provide a deeper illumination. This makes it useful for detecting evidence of past events and other materials which may be difficult to discern with visible light. It is also safer to use than short-wave UV light due to its lower intensity.

Another benefit of black light is that it is often used to detect counterfeit currency and documents. The unique wavelength of black light is able to reveal details which may be otherwise impossible to detect with the naked eye.

Finally, black light is often used in the entertainment industry for its unique visual effects.


Choosing the Right UV Torch Light

When choosing a UV torch light, it is important to consider the application you will be using it for. If you are looking for the most common type of UV torch, then a 365nm UV torch light is likely the best option.

It is also important to select a torch light with the proper voltage. A lower voltage is better for counterfeit detection because it produces less heat, making it easier to detect subtle differences in materials. Higher voltages, however, produce a brighter light and are better suited for entertainment and other purposes.

Finally, it is important to consider the quality of the torch light when making your selection. Look for one that is made of durable materials and has a reliable power source. Make sure the torch light is within your budget.

Click here for a complete guide to choosing the right UV torch.


Arkfeld UV LED Torch 365nm

The new product Arkfeld UV LED Torch released in March 2023 has both UV light and LED light, dual light source lighting.

As mentioned above its name, it has 365nm UV lamp, Optical Power is 580mw.

The maximum output of the LED is 1000 lumens, and the longest distance of the beam is 85m.

Small size and portable.

After reading the above introduction, are you excited about Arkfeld UV? Click here to buy!

How Do I Choose the Right UV Torch?
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