The collection of luminous intensity emitted by a source of light in all directions is known asluminous distribution. The sources of light used in practice have a more or less large luminous surface, whose radiation intensity is affected by the construction of the s ource itself, presenting various values in these scattered directions. Special devices …
The Physics of Light
Man has always been fascinated by light and has constantly striven to unravel its mysteries. History has produced various theories that today strike us as comical but were seriously propounded in their time. For example, since no connection could be discerned between a flame and the object it rendered visible, it was at one time …
Basic parameters used in lighting you should know
Luminous flux Abbreviation: φ phi Unit: lm lumen The luminous flux describes the quantity of light emitted by a light source. The luminous efficiency is the ratio of the luminous flux to the electrical power consumed (lm/W). It is a measure of a lamp’s economic efficiency. Luminous intensity Abbreviation: I Unit: cd candela The luminous …
Illuminance recommendations
Recommended minimum illuminances (E) for typical interior lighting tasks. The illuminances are aimed at a lighting level appropriate to the specific visual tasks to be performed in the space or in a part of the space. They do not include architectural lighting components or other aspects for the specific situation. The average horizontal illuminances quoted …
Visibility and visual performance of good lighting
Human beings need to be informed about their surroundings in order to perform their activities in an easy and harmless fashion. Most information about the environment reaches human beings through their eyes. Therefore, it is of a visual nature. The term visibility (of an object) is used as a measure of easiness, fastness and precision …
Technical analysis of LED light
A Light Emitting Diode (LED) is a semiconductor device which converts electricity into light. Each diode is about 1/4 inch in diameter and uses about ten milliamps to operate at about a tenth of a watt. LEDs are small in size, but can be grouped together for higher intensity applications. LED fixtures require a driver …
How to achieve energy-efficient lighting?
Technological development has focused primarily on such things as the fluorescent lamp and the ballast and has chiefly been geared to boosting their luminous efficacy. The chart “Milestones to energy conservation with modern lighting” shows how much has been achieved in reducing power requirements. The first breakthrough came with the development of new low-loss ballasts …
Power supply of luminaires with magnetic ballasts
The magnetic ballast Fluorescent tubes and discharge lamps require the intensity of the arc to be limited, and this function is fulfilled by a choke (or magnetic ballast) placed in series with the bulb itself (see fig. 5 ). This arrangement is most commonly used in domestic applications with a limited number of tubes. No …
Lighting quality, how to achieve?
Achieving the required illuminance level does not necessarily ensure good lighting quality. The quality as well as the quantity of illuminance is important to produce a comfortable, productive, aesthetically pleasing lighting environment. The quality of the lighting system refers, but is not limited to, aspects of lighting such as proper color, good uniformity, proper room …
Lights up, the facts about lighting!
Illuminance is light falling on a surface measured in footcandles or lux. Distributed with an economic and visual plan, it becomes engineered lighting and, therefore, practical illumination. A lighting designer has four major objectives: Provide the visibility required based on the task to be performed and the economic objectives. Furnish high quality lighting by providing …
