24.01.2015
The blue line indicates the approximate intensity of radiation that penetrates Earth's atmosphere at wavelengths from the ultraviolet (UV) through the visible to the infrared. A research study looking at paint degradation caused by illumination has been misinterpreted to throw LEDs into a bad light. Museums and art galleries are often touted as excellent applications for high-quality LED lighting, provided that the necessary targets for characteristics such as color rendering can be met.
However, many different materials are used in works of art, and each can respond differently when exposed to different wavelengths of light. But on closer inspection, it turns out that the scientists didna€™t actually use LED lights at all. The link between the results and LED lighting originated with a press release from the University of Antwerp in Belgium, entitled a€?LED lights may be bad for Van Gogh paintings.a€? This describes the work of a group of researchers from Italy, Belgium, Netherlands, France and Germany, who investigated changes in color of yellow lead- and chrome-containing pigments used by Van Gogh and other painters. The darkening effect decreased from a€?UV-Visa€? to a€?UVa€?, then a€?bluea€? then a€?red.a€? When looking for an LED comparison, the a€?bluea€? filter produces a much broader peak in the blue spectral region than is observed for a typical white LED. Soraa, the California-based LED lamp manufacturer, has looked into this issue and provided further technical analysis. According to Soraa, the Xenon lamp used in the study has a spectrum that is a€?vastly different from those of white-emitting LEDs for illumination.a€? Fig.
Degradation of the paint samples was observed under intense irradiation, said Soraa, amounting to more than 1000X the values used in conventional illumination, when the a€?bluea€? (335-525 nm) filter was used. Soraa contends that photo-oxidation effects are more probable as excitation wavelengths get shorter, and therefore the energy of the radiation is higher. Whatever the reason for the degradation observed in the Van Gogh paintings, it is clear that the people responsible for illuminating art and museum pieces need to be aware of potentially detrimental effects of using certain light sources.
However, instead of relying on erroneous press reports with knee-jerk warnings against LEDs, perhaps they should consider funding some research that actually uses LEDs.
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Subscribe to the magazine or email newsletter today at no cost and receive the latest news and information. A report created by the Lighting Research Center is posted on the Bonneville Power Administration website detailing tests of LED luminaires and lighting controls in open office and conference room spaces. Smart lighting for the home can now easily flash Twitter alerts, sports scores, weather changes, and more via IFTTT.
The US Department of Energy has released a new Caliper Snapshot report on linear LED tubes intended as fluorescent replacements and such lamps now represent the majority of all lamps listed in the Lighting Facts database. Ultraviolet (UV) radiation comes from natural sources (like the sun), and artificial sources (like black lights, welding equipment, lasers, and tanning beds and lamps). Being exposed to too much artificial or natural UV radiation can cause skin cancer and other serious health problems.
This is an image of the different types of electromagnetic radiation.A  It is displayed as a line graph where the forms of electromagnetic radiation are plotted along a continuum in descending order of size and range. Radiowaves (wavelength range from 10 to the power of -1 metres to 10 to the power of 6 metres and beyond).
The highest energy and shortest wavelength electromagnetic radiation is the Gamma Ray.A  The lowest energy and longest wavelength electromagnetic radiation is the Radiowave. The second layer of the image displays detailed information about the range of Ultraviolet radiation, Visible light, and Infrared radiation.A  They are displayed along a continuum beginning with the types of Ultraviolet light, continuing with Visible light, and ending with Infrared radiation.
A Ultraviolet radiation is shown to have a range of types.A  The types of radiation are displayed from left to right in descending order as UVC rays, UVB rays and UVA rays.


Along the same continuum in the image, Visible light is displayed after the Ultraviolet radiation waves.A  Visible light is displayed as having a range from 375 nanometres to 725 nanometres.
After the display of the range of Visible light, Infrared radiation is placed last along the continuum.A  Infrared radiation displayed as having a range from 725 nanometres to beyond 825 nanometres. Ultraviolet radiation is invisible energy in the wavelength range from 100 to 400 nanometers (nm).
You need protection from UV rays on both sunny and cloudy days, since up to 80% of the sun's rays can get through light cloud, mist, and fog. Time of day - UV radiation from the sun reaches its peak at solar noon, which is between 12 and 1 p.m.
Season - During the year, the sun's angle varies, which causes the intensity of UV rays to vary.
Ozone layer thickness - A decrease in thickness of our ozone layer results in an increase in UV intensity.
Weather conditions - Cloud cover can greatly affect the amount of UV radiation that reaches the earth's surface.
Altitude - UV radiation increases with altitude (height above sea level) because there is less atmosphere to absorb the damaging rays. Many countries around the world, including Canada, have recognized this problem and have taken steps to protect the ozone layer from more damage. In 1987, Canada was one of 24 nations to sign the Montreal Protocol on Substances that Deplete the Ozone Layer. Canada has phased out the production of all ozone-depleting chemicals, and has taken steps to control their use through regulations that are part of the Canadian Environmental Protection Act. Health Canada's Consumer and Clinical Radiation Protection Bureau assesses, monitors, and helps reduce health and safety risks from radiation emitting devices and other sources of radiation, including tanning equipment.
Health Canada has partnered with Environment Canada to create the UV Index Sun Awareness Program. The Public Health Agency of Canada monitors cancer in Canada and develops programs to reduce cancer risks.
Light at low UVC wavelengths is completely absorbed by the atmospheric ozone layer, so organisms on Earth have developed no tolerance to it.
Among the benefits provided by LED lighting, alongside energy savings, is the lack of ultraviolet (UV) and infrared (IR) radiation. In fact, one set of scientific results looking at yellow paints used over a century ago has resulted in some very bad press for LED lighting. Instead, they used a high-intensity Xenon lamp (Cermax 175W) in combination with various wavelength filters. None of the other filters produce spectra that bear any relation to conventional white LEDs. 2 compares the spectra of the Xenon lamp, a halogen lamp, and Soraaa€™s 2700K Vivid LED MR16 lamp. This energy (also known as the electromagnetic spectrum) includes radiowaves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. It can just penetrate the outer protective layer of the skin and is responsible for delayed tanning, sunburns and most skin cancers. Wear light-coloured, long-sleeved shirts, pants, and a wide-brimmed hat made from breathable fabric.
Tune into local radio and TV stations or check online for the UV index forecast in your area.


If sunny days are also hot and humid, stay cool and hydrated to avoid heat illness.A  Dehydration (not having enough fluids in your body) is dangerous, and thirst is not a good indicator of dehydration. The UV index measured in Edmonton will be less than that measured at the top of a mountain in Jasper. But over time, the release of certain chemicals into the environment has damaged the ozone layer.
Efforts have focused mainly on controlling the production and use of chemicals known to damage the ozone layer.
This program helps elementary and high school teachers teach their students how to use the UV index, so they can protect themselves from the harmful effects of the sun. Health Canada promotes public awareness about sun safety and the harmful effects of UV radiation.
A small-scale, low-power light source emitting in the UVC range could therefore be useful for sterilization applications. The absence of IR means that the LED light source does not produce heat, and can be placed close to the piece to be illuminated.
Darkening of the yellow paint samples was most pronounced for the a€?UVA-Visa€? filter, but as Fig.
This can cause immediate tanning and premature skin aging, and play a role in the development of certain skin cancers.
A large amount of UVB is absorbed by the ozone layer - only 5% reaches our planet's surface.
At this time, the sun's rays have the least distance to travel through the atmosphere, increasing the intensity of UV. But the sun can still have an effect on your skin and eyes in the fall and winter, especially when UV is reflected back by large surfaces of fresh snow. Also, pollutants like the chlorine from chlorofluorocarbons destroy ozone molecules at a faster rate. If you are skiing on a spring day at the end of March, for example, the reported UV index may only be 4, but because of reflection from the snow, you may experience a UV index of 7. At an altitude of around 2,000 metres, the amount of UV radiation can be up to 30% higher than at sea level.
Previous work had led to indium gallium nitride and aluminium gallium nitride light-emitting diodes (LEDs) that emit at blue2 and UVB (ref.
Meanwhile, the absence of UV is said to prevent degradation of potentially sensitive materials.
Depending on its wavelength, it can get through the ozone layer and affect our health in different ways.
On the other hand, scattered clouds can actually increase the amount of UV radiation at the surface of the earth because of reflection.
Look for places with lots of shade, like a park with big trees, partial roofs, awnings, umbrellas or gazebo tents.
The intensity of UV radiation also depends on which pressure system is influencing the weather. A high-pressure area causes a thinner ozone layer, while a low-pressure area causes a thicker ozone layer.



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Comments Uv led intensity unit

  1. P_R_I_Z_R_A_K
    Unless it is treated with the UV LED so it won't used along.
  2. STOUN
    Know that these photosensitizing effects forces.