The document discusses different types of electric lamps used for artificial lighting. It describes lamps such as incandescent, fluorescent, mercury vapor, metal halide, and high/low pressure sodium vapor lamps. Each type of lamp uses a different light-generating process and has varying efficiencies. The most efficient modern lamp is the LED, which produces light via semiconductors and can achieve up to 90% efficiency compared to incandescent bulbs.

1. ELECTRIC LAMPS
ARTIFICIAL LIGHTING
_JANANI M

2. THE LAMP IS ONE KIND OF LIGHT SOURCE THAT INCLUDES AN ELEMENT FOR
LIGHT-EMITTING IN A TUBE OR OUTER BULB WHICH NORMALLY GENERATES
RADIATION IN THE VISIBLE SPECTRUM.
THE TERM ‘BULB’ IS USED TO REPRESENT A LAMP BUT IT IS AN EXTERNAL
GLASS PART THAT INCLUDES THE LIGHT SOURCE.
IT IS THE MOST COMMON FORM OF ARTIFICIAL LIGHTING.
ELECTRIC LAMPS

4. DIFFERENT TYPES OF LAMPS
INCANDESCENT
TUNGSTEN HALOGEN
FLUORESCENT
COMPACT
FLUORESCENT
MERCURY VAPOUR
METAL HALIDE
HIGH-PRESSURE
SODIUM VAPOUR
LOW-PRESSURE
SODIUM VAPOUR
LED

5. INCANDESCENT LAMPS
THE INCANDESCENT LIGHT OR LAMP IS AN ELECTRIC LIGHT SOURCE
THAT FUNCTIONS THROUGH FILAMENT HEATING.
THESE ARE AVAILABLE IN AN EXTENSIVE RANGE OF WATTAGES,
VOLTAGES & SIZES.
THESE LAMPS ARE DESIGNED WITH GLASS INCLUDING A TUNGSTEN
FILAMENT.

6. TUNGSTEN HALOGEN LAMPS
A TUNGSTEN HALOGEN LAMP IS ALSO CALLED QUARTZ IODINE & QUARTZ-
HALOGEN, IS ONE KIND OF INCANDESCENT LAMP THAT INCLUDES A
TUNGSTEN FILAMENT ENCLOSED WITHIN A SOLID TRANSPARENT COVER.
THE FILAMENT OF A TUNGSTEN HALOGEN LAMP HAS TWO PURPOSES. ONE
IS TO GENERATE LIGHT, AND THE SECOND IS TO GENERATE THE HEAT
NECESSARY TO OBTAIN A WALL TEMPERATURE EXCEEDING 250OC.

7. FLUORESCENT LAMPS
A FLUORESCENT LAMP, OR FLUORESCENT TUBE, IS A LOW-PRESSURE
MERCURY-VAPOUR GAS-DISCHARGE LAMP THAT USES FLUORESCENCE TO
PRODUCE VISIBLE LIGHT.
A FLUORESCENT LAMP CONVERTS ELECTRICAL ENERGY INTO USEFUL LIGHT
MUCH MORE EFFICIENTLY THAN AN INCANDESCENT LAMP.

8. MERCURY VAPOUR LAMPS
A MERCURY-VAPOUR LAMP IS A GAS-DISCHARGE LAMP THAT USES AN
ELECTRIC ARC THROUGH VAPOURIZED MERCURY TO PRODUCE LIGHT.
THE ARC DISCHARGE IS GENERALLY CONFINED TO A SMALL FUSED QUARTZ ARC
TUBE MOUNTED WITHIN A LARGER BOROSILICATE GLASS BULB.
THE OUTER BULB MAY BE CLEAR OR COATED WITH PHOSPHOR

9. METAL HALIDE LAMPS
A METAL-HALIDE LAMP PRODUCES LIGHT BY AN ELECTRIC ARC THROUGH
A GASEOUS MIXTURE OF VAPOURIZED MERCURY AND METAL HALIDES.
THEY ARE SIMILAR TO MERCURY VAPOUR LAMPS, BUT CONTAIN
ADDITIONAL METAL HALIDES.
THE MOST COMMON METAL HALIDE COMPOUND USED IS SODIUM IODIDE.
METAL-HALIDE LAMPS HAVE A HIGH LUMINOUS EFFICACY OF AROUND 75–
100 LUMENS PER WATT.

10. HIGH-PRESSURE SODIUM VAPOUR LAMPS
THEY ARE WIDELY USED IN INDUSTRIAL LIGHTING, ESPECIALLY IN
LARGE MANUFACTURING FACILITIES,AND ARE COMMONLY USED AS
PLANT GROW LIGHTS.
THEY CONTAIN MERCURY.
ABOUT 100 LUMENS PER WATT
LOW-PRESSURE SODIUM VAPOUR LAMPS
LOW-PRESSURE SODIUM (LPS) LAMPS HAVE A BOROSILICATE GLASS
GAS DISCHARGE TUBE (ARC TUBE) CONTAINING SOLID SODIUM AND A
SMALL AMOUNT OF NEON AND ARGON GAS IN A PENNING MIXTURE TO
START THE GAS DISCHARGE.

11. LED LAMPS
LED LIGHTING PRODUCTS PRODUCE LIGHT UP TO 90% MORE EFFICIENTLY
THAN INCANDESCENT LIGHT BULBS.
AN ELECTRICAL CURRENT PASSES THROUGH A MICROCHIP, WHICH
ILLUMINATES THE TINY LIGHT SOURCES
TO PREVENT PERFORMANCE ISSUES, THE HEAT LEDS PRODUCE IS ABSORBED
INTO A HEAT SINK.
COMMON LED COLORS INCLUDE AMBER, RED, GREEN, AND BLUE.