The following points highlight the two important laws of illumination. The laws are: 1. Inverse Square Law 2. Lambert's Cosine Law. 1. Inverse Square Law: The illumination of a surface is inversely proportional to the square of distance between source and light surface provided that the distance between the surface and the source is sufficiently large so that source can [...]
The following points highlight the top eight types of lamps. The types are:- 1. Arc Lamps 2. Carbon Arc Lamp 3. Incandescent Lamps 4. Carbon Filament Lamps 5. Tungsten Filament Lamps 6. Gaseous Discharge Lamps 7. Metal Halide Lamp 8. Neon Lamp. Type # 1. Arc Lamps: In an arc lamp electric current is made to flow through two electrodes. [...]
In this article we will discuss about:- 1. Introduction on Halogen Lamp 2. Principle of Operation of Halogen Lamp 3. Safety 4. Handling Precautions. Introduction on Halogen Lamp: A halogen lamp (also called tungsten-halogen lamp or quartz halogen lamp) is an incandescent lamp wherein a tungsten filament is sealed into a small transparent envelope filled with a halogen gas such [...]
Learn about the comparison between filament lamps and fluorescent lamps. Comparison # Filament Lamp: 1. Simple, reliable and cheap. 2. Average life 1000 hrs. 3. Reddish Light. 4. Life is not affected by frequent switching. 5. No stroboscopic effect. 6. Voltage variations, which vary with the wattage, affect the temperature, efficiency and also the life. 7. Brightness is very high [...]
The following points highlight the four main factors to be considered while selecting lamps. The factors are: 1. Fitting Required for Filament Lamp 2. Lamp Connection Caps 3. Reflectors 4. Diffusers. Factor # 1. Fitting Required for Filament Lamp: Light fitting should be made of cold rolled annealed steel sheets duly oiled and picked against rust. Fitting for outdoor use [...]
A number of methods have been employed for lighting calculations, among which may be mentioned as: 1. Watts for Square Meter Method 2. Lumen or Light Flux Method 3. Point to Point or Inverse-Square Law Method. 1. Watts for Square Meter Method: This is principally a "rule of thumb" method, very handy for rough calculation or checking. It consists in [...]
In this article we will discuss about the nature of light. Lighting is one of the major uses of electrical energy. Sun is the biggest source of natural light. Artificial lighting may be electrical or non-electrical. Where there is no natural light, use of artificial light is made. Artificial lighting produced electrically has advantages like cleanliness, ease of control, reliability, [...]
The following points highlight the five main points to be kept in mind while making choice of lighting system for street lighting. The points are: 1. Initial Cost and Cost of Replacements 2. Life of Lamp 3. Operational Costs 4. Quality of Light 5. Efficiency. 1. Initial Cost and Cost of Replacements: The tungsten filament lamp is the cheapest with [...]
In this article we will discuss about the types of interior lighting schemes and the factors that are required to be considered while designing the lighting scheme. Types of Lighting Schemes: i. Direct Lighting: It is most commonly used type of lighting scheme. In this lighting scheme more than 90 percent of total light flux is made to fall directly [...]
Here is an experiment on the ‘Sources of Light’ especially written for school and college students. Aim of the Experiment: Study of different types of sources of light and make connections, and measure intensity of light with lux meter. Objective: To measure the intensity of light with lux meter of: (i) Fluorescent lamp (ii) H.P. mercury vapour lamp (iii) H.P. [...]