A comprehensive list of UV industry related terms and their definitions;
The occurrence of airborne pollution (e.g. mercury) falling to the ground in precipitation, dust, due to gravity. Also known as “atmospheric deposition”.
A protective non-conductive dielectric layer that is applied onto the printed circuit board assembly to protect the electronic assembly from damage due to contamination, salt spray, moisture, fungus, dust and corrosion caused by harsh or extreme environments.
Crystallisation of a formerly non-crystalline (amorphous) glass such that its ability to transmit a range of electromagnetic radiation (e.g. UV) is greatly reduced.
Describes materials with the property to selectively reflect or transmit a specific wavelength range. Dichroic UV reflectors that reflect less long wavelength radiation such as IR are called “cold mirrors” while those that reflect more are called “hot mirrors”.
An electrical insulator that can be polarised by an applied electric field.
The maximum electric field a material can withstand intrinsically before it breaks down and becomes a conductor of electricity.
Discharge Tube/UV Lamp
A lamp envelope containing electrodes, a starting gas that is ionised by an electric field and other additives. The additive atoms / ions are excited to high energies and emit a UV photon as they return to their ground state.
Also known in the industry as a metal halide lamp, contains an additive, such as gallium or iron, to alter the spectral output to cure different types of inks/coatings/adhesives.
An electric current involving an ionised gas, such as argon, leading to the formation of a plasma arc.
In simple cases, the electric field between two points is the voltage between those points divided by the distance between them.
A device to prevent excess current flowing into a lamp and can also assist in lamp ignition.
Electromagnetic Spectrum / Radiation
The entire range of all possible electromagnetic radiation. This includes gamma rays, X-rays, ultraviolet, visible light, infra-red, microwaves and radio waves.
Elemental (Metallic) Mercury
One of the three chemical forms of mercury, which usually causing health effects when inhaled in vapour form. Exposures can occur when elemental mercury is spilled or products that contain elemental mercury break and expose mercury to the air, particularly in warm or poorly-ventilated indoor spaces.
The lowest energy state of an electron.
Chemical elements in group XVII of the periodic table, including fluorine, chlorine, bromine, iodine and astatine.
The band of the electromagnetic spectrum ranging between 750nm to 1mm.
Isopropyl (Isopropanol) Alcohol
A colourless and relatively non-toxic alcohol. It evaporates quickly and can dissolve various oils, so is useful for cleaning quartz cooling tubes, UV reflectors and UV lamp bodies.
A chemical compound involving a metal and a halogen.
An organic mercury compound formed through microbial activity when mercury is introduced to a water supply. Mercury is harmful to aquatic wildlife and animals (including humans) that ingest it.
A silvery metal with the chemical symbol Mo and atomic number 42. It has the sixth-highest melting point of any element. It is frequently used in the seal of UV lamps due to its relatively low thermal expansion and high electrical conductivity.
A term used in industry to measure specific wavelengths of the electromagnetic radiation spectrum – One billionth of a metre, 1 millimetre = 1000th of a metre, 1 micrometre = 1000th of a millimetre, 1 nanometre = 1000th of a micrometre One billionth of a metre, 1 millimetre = 1000th of a metre, 1 micrometre = 1000th of a millimetre, 1 nanometre = 1000th of a micrometre
Chemical elements in Group XVIII of the periodic table with similar properties such as being odourless, colourless and of low reactivity. This includes helium, neon, argon, krypton, xenon and radon.
A compound that undergoes chemical reaction(s) when subjected to electromagnetic radiation.
A process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.
The use of UV light in the treatment of physical or mental illness.
Also known as PUVA is the use of UV light in the treatment of cancer.
Psoralen (P) and ultraviolet A (UVA) therapy. This is a UV light therapy used to treat skin conditions such as eczema and vitiligo.
A glass-like material made of silicon dioxide with various forms. It has low thermal expansion and a very high melting point of around 1665 °C. The ‘fused quartz’ form transmits UV very effectively.
Moving the electromagnetic radiation output of the UV lamp, by doping with certain additives. This may include increasing the intensity of the radiation or shifting the range of wavelengths (nm) of the radiation.
Thin Layer Chromatography (TLC)
A process involving UV light which chemists use to identify the components in a mixture.
An electrical device used to step-up or step-down the voltage of alternating currents.
A conductor through which electricity enters a UV lamp.
Also known as “Longwave UV”. UVA has a wavelength range of 400 — 315 nm. It is the least harmful of the three UV wavelengths but can still contribute to the ageing of skin, DNA damage and possibly skin cancer. UVA lamps are used for curing of inks, adhesives and coatings and specifically; screen printing and flexo printing.
Also known as “Midwave UV” or “Medium Wave UV”. UVB has a wavelength range of 315 – 280 nm. It is more dangerous than UVA and is responsible for burning the skin among other things. In industry UVB lamps are used for curing of inks, adhesives and coatings and specifically clear coatings and thin ink layers.
Also known as “Shortwave UV”. UVC has a wavelength range of 280 – 100 nm. It is the most harmful and highest energy of the three UV wavelengths. In industry UVC is used for water and air disinfection as it can render micro-organisms harmless.
Refers to treatment of a substrate with UV radiation to cure the surface or protect the underlying material from its harmful effects.
Is a photochemical reaction (photopolymerisation) when specialised coatings are exposed to UV light they cure, instead of relying on heat and time to evaporate carriers like in solvent-based coatings.
A property of electromagnetic radiation – by altering the wavelength (nm) you can cure / disinfect various types of substrates.
The Waste Electrical and Electronic Equipment Directive (WEEE Directive) is the European Community directive 2002/96/EC on waste electrical and electronic equipment (WEEE).