LIGHTING TERMINOLOGY

Evolution of light sources

Tungsten filament bulb
Traditional light bulbs were made of an air-tight glass with a filament of tungsten wire inside the bulb, through which an electric current passed. These bulbs would get very hot, emitted a warm light and were generally used in a home environment. Limited shapes and sizes were available in daylight colour temperature but weren’t ideally suited for working on precise tasks.
The tungsten filament bulb is now phased out in Europe, they can no longer be manufactured or imported, however, they can still be sold.

Halogen bulb
The Halogen bulb is a modern version of the filament bulb as in the filament burns in halogen gas. Although much better at energy efficiency than its predecessor, the Halogen bulb would get extremely hot, came in limited shapes and again, simulating a daylight colour temperature was not possible.

Compact fluorescent bulbs & tubes
A more modern version of the long fluorescent office and kitchen tube; the compact version was much better at energy efficiency. The technology allowed to produce a daylight simulation colour temperature, the bulbs and tubes could be produced in various shapes and sizes and lasted up to 10,000 hours of light while generating low heat output. However, the down side of the technology was that it was fairly slow at reaching full brightness and adding a dimming function to it was not an easy task.

Light Emitting Diodes (LED)
An LED is made of Solid State components which are very strong, very compact and available in all colour temperatures – including daylight (simulation of the daylight). LEDs emit a very low heat meaning that people can work under and LED light for many hours without it ever getting hot. It uses on average 80% less energy compared to an incandescent lamp, making it the greenest technology so far. It also has a very long life, lasting up to 50,000 hours.

Lumens & Lux

Lumens (lm)
Lumens, also known as “luminous flux”, describes the amount of light that is emitted from a light source and radiating equally in all directions. It is the measure of the perceived brightness of a light source as it appears to the human eye.

Lumens do  not change with distance; whether standing at 1 metre or at 10 metres from a light source, the light source is giving the same lumen output.

Light bulbs are best measured in lumens because the light from a typical light bulb is attempting to cover 360º degrees. however, light bulbs usually achieve ~320º degrees.

Lumens & task lighting
Lumens measure the amount of light that is emitted in all directions. As a result, the lumen value is  not indicative of the amount of light that is directed at the work surface. When choosing a task light, the lumen value can be misleading.

Lux

Lux values represent the actual amount of light on a surface or defined area at a given distance. It is the most accurate way of measuring the real light output of a lamp on the work surface.

– Lux values must always be associated with a distance (the same lamp measured at 15 cm will be brighter than at 30 cm)
– Lux values are measured using a Lux Meter at a fixed distance:
– For Task Lamps we measure at 30 cm (12″)
– For Magnifiers we measure at 15 cm (6″)

The Lux value quoted is the maximum value at the brightest point on the work surface, below the centre of the shade.

In summary

Lumens is the measure of light radiating in all directions equally and therefore does not indicate the amount of light falling on the work surface.

Lux is the actual amount of light on your work surface. When comparing different lamps, Lux is the value to look for to determine which has the highest output onto the work surface, provided that Lux is measured at the same distance.

Colour Temperature (Kelvin)

Colour Temperature (Kelvin)

The colour temperature is measured in Kelvin (K) and refers to the colour temperature of a light source as it is perceived by the human eye.
The colour temperature is obtained by heating a block of carbon to a specified temperature and observing the colour it glows.

For example:
A colour temperature of around 2,700 K gives off an orange colour. Similarly, a sunrise or sunset gives off a very warm feeling.

A colour temperature of around 10,000 K gives off a blueish colour. Similar to a blue sky which gives off a cool feeling.

A colour temperature of between 5,500 K and 6,500 K gives off a white colour, known as daylight. This is similar to a sunny day, when the sun is high for example at 12 noon.

The industry terms used to describe the different colours of artificial light are:

Colour description Kelvin value
Warm white 2,700 K
Cool white 4,000 K
Daylight 5,500 K to 6,500 K

At the Daylight Company, all LED Lamps & Magnifiers are built to produce a daylight colour temperature of 6,000 K.

Colour Rendering Index (CRI)

What is CRI?

The Colour Rendering Index (CRI) is a scale from 0 to 100. CRI is used to measure how accurate an artificial light source is at revealing colour in comparison to a natural light source (eg: the sun). A high CRI indicates that a lamp is better at rendering colours truly, a value of 100 CRI represents the sun.

The higher the CRI value (also called CIE Ra), the more accurate the colours will be.

Read the full research here

Dioptre & Magnification

Dioptre & Magnification

Dioptre refers to the curvature of the lens. As the dioptre increases, the lens becomes thicker and the curvature greater. As the curvature increases, light rays are redirected to fill a greater portion of the viewer’s retina which makes the object look bigger.

Power (magnification) refers to how much larger an object is made to look through a magnifying lens. Power is typically indicated by an X such 2X or 4X.

For example:
A 3 dioptres lens makes an object look 75% larger,
A 5 dioptres lens makes an object look 125% larger,
An 8 dioptres lens makes an object look 200% larger,
over and above what the unaided eye already sees.

Read the full research here

ESD

What is ESD?

Electrostatic discharge (ESD) is the sudden and momentary flow of electric current between two objects caused by direct contact, or an electrostatic field. The term is used in the electronics industry to describe momentary unwanted currents that may cause damage to electronic circuits & components.

ESD is a serious issue in solid state electronics, such as integrated circuits and steps must be taken to prevent it. Semiconductor materials such as silicon can suffer permanent damage when subjected to high voltage; as a result all products and equipment used during the assembly or inspection of PCB boards should protect from ESD damage.

Read the full research here

Environmental information

RoHS
Restriction of Hazardous Substances (RoHS) is an EU Directive that came into force in 2006 and applies to Electrical and Electronic Equipment.

The Directive restricts the use of six hazardous materials in the manufacture of various types of electronic and electrical equipment. It is closely linked with the Waste Electrical & Electronic Equipment (WEEE) Directive which sets collection, recycling and recovery targets for electrical goods and is part of a legislative initiative to solve the problem of huge amounts of toxic electronic waste.

The purpose of the Directive is to severely restrict the use of substances that are considered hazardous to the human health and to the environment, in electrical products.

It is a legal requirement that all Electrical Products sold in the EU comply with the Directive.

The six substances covered by the legislation and the limit for each are show in the table below:

Substance Limit
Lead < 0.1%
Mercury < 0.1%
Cadmium < 0.01%
Hexavalent Chromium < 0.1%
PBB (flame retardant) < 0.1%
PBDE (flame retardant) < 0.1%

 

The Daylight Company is concerned with the directive for its lamps and luminaires but it does not apply to our range of accessories; floor stands, table bases, cutting mats, clamps.

The Daylight Company has signed agreements with its suppliers and they are required to produce products that comply with the Directive.

ROHS is now part of the CE Marking Directive and does not require its own mark.

WEEE
Waste of Electrical & Electronic Equipment (WEEE) is an EU Directive which set collection, recycling and recovery targets for all types of electrical goods. The Directive was implemented in all EU Member States in an effort to meet the EU target of recycling of electrical and electronic equipment.

The symbol adopted by the European Council to represent WEEE comprises a crossed-out wheelie bin.

Companies have a legal responsibility to facilitate and fund recycling costs. In the UK, the responsibility lies with The Daylight Company as a manufacturer of electrical products, our distributors and retailers. In other EU countries, the responsibility to recycle falls under the distributor and or retailer of our products.

Our range of lamps and magnifiers fall under the scope of the Directive and all bear the crossed out wheelie bin logo.

In the UK, the Daylight Company is a member of the WeeeCare Compliance scheme and is registered with the Environment Agency with Registration Number WEE/JF0004ZR. The scheme supports its members to comply with the Directive by carrying out audits of our premises to ensure that we are fully compliant.

The Daylight Company is a member of the Electro-G scheme in Germany.

Why recycle?
Unwanted electrical equipment is one of the fastest growing type of waste.
Most electrical items can be repaired or recycled, saving natural resources and the environment. If you do not recycle, electrical equipment will end up in landfill where hazardous substances can leak out and cause soil and water contamination – harming wildlife and human health.

Where to recycle?
We recommend that you first check with your local authority to locate your local recycling centre or a local retailer of electrical equipment.

If you wish to return a Daylight product for recycling directly to us, you can do so, simply send your item to our head office and we will take care of recycling it. Please note that carriage cost to send the item to us is at your own charge.

For more information on recycling electrical appliances please visit recyclingnearyou.com.au/electrical/

Battery Directive
The Daylight Company follows the EU Battery Directive which regulates the manufacture and disposal of batteries in the European Union with the aim of “improving the environmental performance of batteries and accumulators”.

Batteries commonly contain hazardous elements such as mercury, cadmium, and lead, which when incinerated or landfilled, present a risk to the environment and human health.

The Directive was adopted on 18 March 1991 to reduce these hazards by harmonising EU member states’ laws on the disposal and recycling of batteries containing dangerous substances.

To find out how to find a battery recycler in Australia visit batteryrecycling.org.au