Glossary

Absorption
Absorption weakens radiation by converting them at least partially. The remaining radiation is either reflected or transmitted.
Absorption usually depends on the wavelength, such in filters or the special BlueQ-glass in which UVB radiation is converted into heat and UVA radiation is transmitted.
The skin transforms radiation into biochemical processes, e.g. skin tannings

Ampere
Ampere is the basic unit of the electric current.

Arcing
A self-sustaining gas discharge between two electrodes.
In this case, light is emitted. Due to the high temperature, the volumic mass is reduced in the arc.
The arc takes an arc shap.
Technical lamps transfer the arc to the inside of a tube with a speciall selected atmosphere.
This allows a variation in intensity and spectral specifications.

Ballast
An electronic current limiter that reduces voltage from 230 V to the voltage required.

Base
is part of a lamp, which makes mechanical and electrical contact with the lamp holder.
Essential features are the qualtity of the electronical contact, the allowed operating temperatue, the high voltage stability to the peaks of ignition voltage and the sensitivity against pollution.

Blue:Q
Blue:Q tanning lamps are made of innovative blue quartz glass, that absorbes more UV-B radiation as conventional quartz glass.
By replacing a conventional tanning lamb by a Blue:Q lamp many tanning beds can be operated within the UVSV regulations.

Brightness
Brightness is the human sensation on the incidence of visible light into the eye. Green light generates even at lower irradiance on the retina the same impression of brightness as blue or red light.
The sensitivity of the human eye is strongly dependent on the wavelength.
Because of the importance ot the visible capabilities, there are a whole set of physical quantities that carry this wavelength dependency already in itself. These are luminous, flux, luminous intensity, illuminance and light density.

Candela
Candela is the unit of SI-base size light intensity and describes, from a source in a specific direction given, brightness (lumen). A candle provides about 1 Candela.
The size includes the human impression of brightness. Therefore pure UV or IR radiation is always 0 Candela.
The corresponding energy magnitude woulb be the radiation intensity. It is then also applicable to radiation sources outside the visible range.

Dose
The irraditon dose is expressed in joules per square meter (J/m²).

Many effects, inclding tanning, evolve with the exposed energy, the accumulated power. So it only causes a slight difference whether you tan twice as long with half intensity. In both cases it is the same dose (J/m²)

Electronic ballast
Electronic ballasts are a modern replacement for conventional magnetic ballasts.

Electronic ballasts

• save energy
• increase the light yield from lamps
• make it possible for fluorescent lamps to switch on straight away without the flickering
• automatically switch off defective lamps

Erythemal irradiance
There is  a spectrally different sensitivity to get a sunburn.
Only a small dose of UVC radiation is enough to cause a sunburn, which would correspond with an average does of UVB and a larg dose of UVA.
The erythemal irradiance indicates the ability to cause a sunburn, whether it is caused by UVA, UVB or a mixture of both.
The unit remains W/m².

Ignitor
Required in addition to a ballast for operating metal vapour lamps.

Immediate pigmentation
Immediate pigmentation is a skin color which appears immediately after a minimum dose. It disappears, depending on the dose, within minutes to a few days.
Behind this is an oxidative process on already existing pigments in the skin. This process is stimulated by the irradiation. If the pigments are not or not yet produced no immediate pigmentation takes place.

Infrared radiation
Part of the electromagnetic spectrum that lies between visible light and microwaves and is not visible to the human eye, but you can feel its warming effect.

Irradiance
It is the ratio between the incoming radiation on an area and the size of this area (in W/m²). It is suitable to describe the radiation exposure on surfaces.

Lifetime
Operating time of a product until a further operation is no longer useful of possible.
This my be the achievement of a performance threshold or the total failure.
For tanning lamps and tubes a time is given to an expected decline is reached e.g. 1000h 20% radiation reduction.
Life specifications are still expected values and do not exclude individual early failures.

Light
Electromagnetic radiation at wavelengths of about 380 nm to 780 nm, which are visible to the human eye.
The based measurements with a few subjects definds spectral sensitivity is based on the photometric sizes with the conversion of Watt (physical value) to lumens (brightness).
Of course there are individueal variations in the spectral sensitivity and can be serious due to aging, cataract surgery of characteristics such as red-green color blindness.

Light therapy
A scientifically acknowledged method for treating a variety of diseases associated with partly seasonal light deficiency.
e.g. disturbance of the day/night rhythm or forms of seasonal affective disorder

Low pressure lamps
These are lamps in which the radiation-generating discharge takes place in an atmosphere with low pressure. Characteristic are narrow line spectra.
Lamps with mercury filling are widespreaded. The mainly radiation is generated in each narrow ranges around 185nm and 254nm.
This radiation can be used for ozone generation in air (185nm) or for sterilization (254nm). The radiation can be easily changed by using different phosphors to longer wavelength UV light or light. Then it's called fluorescent lamp.
Typical characteristic for efficient low-pressure lamps are heated electrodes and the large extension of the light source.
The efficiency strongly dependens on the ambient temperature.

LVD
LVD is the Low Voltage Directive of the European Union.
It regulates the safe operation of household appliances, including sundeds.
All EU member states have to follow the LVD regulations - therefore it is also called "Euro norm".
The EU has set the irradiance for sunbeds to 0,3W/m² in January 2007.
This radiation corresponds to the midday sun at the equator.

Melanin
Reddish, brown or black pigments that cause the color of the skin, hair, and eyes and serve as effective protection from the harmful effects of UV radiation.
There are large individual differences in the melanin concentration in the skin (tanning). Depending on the preirradiation the protective effect is stronger or weaker. So the positive effect of UV radiation still can take place e.g. production of Vitamin D

Mercury
A sliver-colored heavy metal that is liquid at room temperature. It has favorable vaporization properties an is easy to excite in the vapor phase, whereby it has excellent properties for efficient generation of radiation.
It resolves alloys spontaneously with many other mettals, called amalgams.
Since it can attack light materials in aircrafts in this way, there are transport restrictions on mercury.
Mercury is toxic. Inhaled mercury vapors are very toxic.
Lamps and spotlights contain a few milligrams of mercury and should not be disposed of with houshold waste.

Optical radiation
Electromagnetic radiation in wavelengths from short-wavelength ultraviolet radiation (100-380 nm) to visible light at 380 to 780 nm and long-wavelength infrared radiation (780 nm to 1 mm).

Photosynthesis
Substandes with a higher energy level are produced by photosynthesis by absorption of light energy.
By using sun energy photosynthesis provides building materials and fuel to any living thing.

Phototherapy
In contrast to the lighttherapy phototherapy has no effect on the impression of brightness in the human eye.
This refers to therapies with influence on the skin by optical radiation e.g. treatment of neurodermatitis and psoriasis.
Mostly this happens also with the inclusion of substances which influence the radiation sensitifity, e.g. in the PUVA therapy.

Reflector
Component, that redirects radiation from a radiation source for a particular purpose.
By the choice of the reflector material, the spectral composition of the reflected radiation can be influenced. Some coated glass reflectors reduce the heat in the radiation field, by being transmissible to infrared radiation.

Spectrum
The spectrum is the segmentation of the radiation according to their wavelength components.

Starter
Starters are componentr for operating a low-pressure lamp with a heated electrode.
Starters have limited life time and must be changed regularly.

Sun-Erythema Factor
The fse is the reference name of the eryhtemal irradiance at 0,3W/m². This value is a typical value at clear sky near the equator at midday.
It is not the highest expected value on earth and it's also reached in areas far away from the equator.
A fse of 100% ist 0.3W/m², 50% is only 0,25W/m².
There are other, similar references e.g. the meteorology UV index.

Transmittance
a measure of how well waves can pass through a given medium

UVA Output
UVA is the radiation in the wavelength range of 315 – 400 nanometres. It is primarily responsible for so-called “instant tanning” – the tanning of pigments present in the skin. This is the tan the customer usually notices immediately after a sunbed session.

UVB Output
UVB is the radiation in the wavelength range of 280 – 315 nanometres. UVB is mainly used to vary the sun-erythema factor of a tube with a determined UVA Output.

UV radiation
an abbrevation for ultraviolet radiation, which is more energetic and has a shorter wavelength compared to visible light and is invisible to the human eye.
UV radiation is further classified as UV-A radiation, UV-B radiation and UV-C radiation.