General Information

When ultraviolet light is mentioned many people immediately think of either sunbeds, counterfeit money detectors, insect traps or fish pond disinfection units.  However UV light is all around us, not just occurring naturally from sunlight but supplied by companies such as UV Light Technology Limited which, through high-tech industrial, commercial, public services and medical applications, make our daily lives more comfortable, secure, healthier and fun!

From treating vitamin D deficiencies and relieving the unsightly effects of Psoriasis, UV light is used in many treatment breakthroughs including fluorescent dyes used in conjunction with blacklight to identify cancerous cells in the internal organs of patients.

In the worlds of science and engineering it is so often vital to establish the ageing effects of the sun on materials for safety and aesthetic reasons.  Ultra violet light sources which closely correlate to natual sunlight are used in a vast range of applications from testing aricraft windscreens to examining the effects of degradation on building materials.

UV blacklight fluoresecent inspection processes make working life easier for quality control engineers, forensic scientists, police officers, fire officers and auction houses to name but a few.  Under UV blacklight hairline cracks can be detected in aircraft undercarriages, automotive steering systems and many of the critical components upon which our lives may depend.  In the field of forensics UV blacklight helps unearth vital evidence at crime scenes and plays an important role in identifying the cause of fires.  The inspection of works of art under UV blacklight is a means of revealing imperfections and evidences of restoratioin, an important aspect of authentication for valuation and sale.

The special effects industry has embraced UV blacklight for its ability to produce stunning visual effects as if by magic (see our UV Scenic Artwork and Effects section for some examples).  Festival tented environments use UV responsive backdrops, bowling alleys create glowing tenpin bowling lanes, pop concerts use multi image 'trompe l'oeil' backdrops illuminated by UV and in night clubs UV is what makes your white clothes glow in the dark!

Microbiologists are employing UV-C germicidal lamps within engineering control measures to reduce infection caused by airbourne transmission of bacterial pathogens within built environments.  Furthermore, some of the water we drink has been disinfected using UV-C light, as has a wide variety of food, drink and medical supplies packaging.

In recent years UV light curing of materials has emerged as perhaps the most exciting and versatile material technology.  These single component, solvent-free material systems cure almost instantaneously on exposure to UV light with efficient use of energy.  They offer unrivalled and unique process advantages in times of stringent legislation changes restricting the use of many solvents.  UV-A, UV-B and UV-C light sources are employed depending upon the type of material to be processed i.e. adhesives, resins, coatings or inks.

The high market growth rate of UV light curing is driven not only by processing and environmentally friendly benefits, but also its capability to provide innovative new processes and product developments.  This cutting edge technology can often provide companies with the ability to exploit new business opporutnities.

Visit the website of UV Light Technology Limited now for further information www.uv-light.co.uk. 

Ultraviolet light (UV) light represents a section of the overall electromagnetic spectrum of light, extending from the blue end of the visible (400nm) to the x-ray region (100nm).

It is subdivided into three distinct wavelength regions described as either UV-A, UV-B or UV-C in increasing order of photon energy.

UV-A 400nm-315nm: Often referred to as 'blacklight', this is the longest wavelength region and lowest energy, it represents the largest portion of natural UV light.

UV-B 315nm-280nm: Partially blocked by the ozone layer this is the most aggressive component of natural UV light and largely responsible for sunburn (erythema).

UV-C 280nm-100nm:  Only generally encountered from artificial light sources since it is totally absorbed by the earth's atmosphere.

The excitation energy provided by UV-A photons is much higher than the energy of the thermal motions of the molecules at physiological temperatures.  Thus the absorbing molecules temporarily assume energy levels that otherwise they would never attain and thus acquire properties differing considerably from those effective in ordinary chemistry.

The lifetime of a molecule in its usual excited state (10[-10] to 10[-8] sec), which is still long compared with the time required for the energy absorption itself (approximately 10[-15] sec), can be greatly extended if the excited electron is trapped in an (energetically somewhat lower) triplet excited state.  In contrast to the usual singlet state, the triplet state is charactereised by two electrons with unpaired spin.  Because the return from the triplet state to the ground state is 'forbidden' (i.e. occurs at a low probability), the triplet may last 10[-3)]sec or even longer and is, therefore, called metastable.

As an excited electron returns to a lower energetic state, its excess energy can be emitted as a photon, resulting in fluorescence.  Fluorescent light is recognised by its usually longer wavelength, compared with the exciting radiation.   Emission from molecules in the metastable excited state occurs over a longer period of time and is called phosphorescence.

Application of fluorescent and phoshorescence for special effects

Fluorescent materials, whilst brighter than most materials under normal light, will glow only when illuminated with ultraviolet (UV-A) blacklight.

Phosphorescent materials will "charge up" under normal visible light and emit light in darkness.  These may also be charged using UV light, for brighter and often longer periods of light emission.  As with fluorescent materials the phosphorescent equivalents will glow under exposure to UV light, but phosphors continue to glow when the UV light source is removed.