Lighting

ALL INDIA INSTITUTE OF LOCAL SELF

GOVERNMENT

DELHI

“ Lighting Concepts for Paramedical”

DR.P.P.SINGH

By

Dr. P.P.SINGH

Faculty AIILSGD

Ex Medical Superintendent Cum Consultant pathologist HRH Delhi

Ex. Director India Population Project 8 Delhi..

SOURCE BOOKS OF AIILSG.

LIGHTING

WE WILL DISCUSS

– WHERE LIGHT COME FROM?.

-- NATURE OF LIGHT.

-- HOW LIGHT BEHAVE?.

-- HOW LIGHT IS MEASURED ?

-- HOW MUCH LIGHT IS

RECOMMENDED FOR VARIOUS

PURPOSES?

LIGHT SOURCES ARE;-

1. NATURAL FROM – SUN & STARS.

( CAN NOT BE CONTROLLED )

2. ARTIFICIAL - SOURCE THAT PEOPLE

CAN CONTROL.

IMPORTANCE OF SUN LIGHT.

--REQUIRED FOR HEALTHY GROWTH .

-- IS ALSO A DISINFECTANT.

-- VISIBLE LIGHT HAS SEVEN COLORS

(VIBGOYR )

-- INVISIBLE - INFRA RED & ULTRAVIOLET

-- GIVES FEELING OF HEALTH & VIGOUR.

-- GOOD SOURCE OF VITAMIN D + SKIN.

-- HELPS IN DEPOSITION OF CALCIUM IN

BONE.

ARTIFICIAL LIGHT

IT HELPS PEOPLE TO DO MANY THINGS THEY

COULD NOT DO WITHOUT NATURAL LIGHT. EX. ;-

-- TO RUN FACTORIES 24 HOURS A DAY.

-- FOR AUTOMOBILES , TRAINS AND AERO

-PLANE TO TRAVEL IN NIGHT.

ARTIFICIAL LIGHT COMES FROM ;-

-- ELECTRIC LAMPS.

--FLORESCENT LAMPS.

-- IN 1950 LASER WAS DEVELOPED.

( LASER IS THE DEVICE A NARROW BEAM OF

PHOTONS ALL OF WHICH HAVE SAME ENERGY.

THE LASER PRODUCE VERY PURE LIGHT OF

SINGLE COLOR.)

* LASER LIGHT HAS MANY USES IN

COMMUNICATION , INDUSTRY , MEDICINE AND

SCIENTIFIC LABORATORIES.

*PROPER AND ADEQUATE LIGHTING IS

ALWAYS REQUIRED FOR EFFICIENT VISION TO

REDUCE STRAIN ON EYE. AND TO REDUCE VISUAL

FATIGUE.

* LIGHT TRAVELS AT 2,99,792 KILOMETERS

( 1,86.282 MILES) PER SECOND.

CHARACTERISTIC OF PROPER LIGHT:

1. IT SHOULD BE SUFFICIENT FOR THE INTENDED USE.

2. IT SHOULD BE UNIFORM WITH SAME INTENSITY.

3. THERE SHOULD BE ABSENCE OF GLARE. ( ALWAYS AVOID IT

CAUSES ACUTE EYE DISCOMFORT.)

4. IT SHOULD BE STEADY. THERE SHOULD NOT BE FLICKERING

BUT CONSISTENCY.

5.THERE SHOULD BE ABSENCE OF SHARP SHADOW .

6. IT SHOULD BE NEARER TO THE DAY LIGHT.

NATURAL LIGHT COMES FROM VISIBLE

SKY AND PARTIALLY BY REFLECTION . THIS

CAN BE IMPROVED BY DIRECTION OF LIGHT .

REMOVAL OF ABSTENTIONS.

PROPER WINDOWS AND INTERIOR OF

ROOM PAINTED IN SUCH A WAY AS TO GIVE

COMFORTABLE CONTRAST . I.E. CEILING

SHOULD BE WHITE , THE UPPER PORTION OF

WALL BE LIGHT TINTED AND LOWER PORTION

SHOULD BE PAINTED SOME WHAT DARKER.

MEASUREMENT OF LIGHT

IT IS MEASURED IN UNIT CALLED FOOT CANDLE IN

BRITISH SYSTEM AND LUX IN METRIC SYSTEM.

IF SOURCE HAS A LUMINOUS INTENSITY OF 1

CANDLE THE MARKED AREA WILL GET LUMINOUS FLUX (

RATE OF LIGHT FALL ON IT )= 1 LUMEN

AN ILLUMINATION OF 1 FOOT CANDLE PRODUCED BY

1 LUMEN OF LIGHT SHINING ON AN AREA OF 1 SQ. FOOT.

AN ILLUMINATION OF 1 LUX IS PRODUCED BY 1

LUMEN OF LIGHT SHINING ON AN AREA OF 1 SQ. METRE.

INTENSITY OF LIGHT

IS INVERSELY WITH THE SQUIRE OF DISTANCE BETWEEN

SOURCE AND THE SURFACE.

= 1/ DISTANCE 2

THIS RELATION SHIP IS CALLED INVERSE SQUARE

LAW

IF THE DISTANCE OF 1 METRE IS MOVED TO 2 METRE

THEN SURFACE WILL RECEIVE (1/2)2 OR ¼ LUX OF LIGHT .

* STUDY OF LIGHT IS CALLED OPTICS .

* SCIENTIST HAS DESIGNED –

MICROSCOPES, TELESCOPES AND OTHER

OPTICAL INSTRUMENTS .

BIOLOGICAL EFFECTS OF LIGHT;-

IT INFLUENCES BODY TEMPERATURE .

IT INFLUENCES PHYSICAL ACTIVITIES .

IT HELPS THE ACTIVATION OF VIT. D.

IT HELPS TO METABOLIZE & EXCRETE

THE BILLIRUBIN.

WAYS OF ARTIFICIAL LIGHTING:

1. DIRECTLY : 99 – 100% ON

WORKING AREA.

2.SEMI DIRECT : 10 – 40% UPWARDS.

3.IN DIRECT : 90 – 100% LIGHT

PROJECTED TO CEILINGS.

4. SEMI INDIRECT : 60 – 90% UPWARDS.

5. DIRECT – INDIRECT : 50% UPWARDS

AND 50% ON OBJECT.

RECOMMENDED ILLUMINATION

1. CASUAL READING 100 LUX.

2. GENERAL OFFICE WORK 400 LUX.

3. FINE ASSEMBLY 900 LUX.

4. WATCH MAKING 2000- 3000 LUX.

NORTH LIGHT

* STRONG SUNLIGHT CAUSES A GLARE

IS HARMFUL TO SIGHT.

*THE SUN LIGHT FROM NORTH SIDE IS

MORE EFFECTIVE AND STEADY .

*THUS LIGHT TO THE INDUSTRIES ARE

USUALLY PROVIDED THROUGH WINDOWS &

VENTILATORS ON TOP OF THE WALL ON THE

NORTH SIDE THEREFORE CALLED “ NORTH

LIGHT’

LIGHTING OF CLASS ROOMS OF SCHOOL:

1. THE MINIMUM HEIGHT OF CLASS ROOM SHOULD BE 3.5

MTS (12 FEET)

2.THE MINIMUM AREA OF CLASS ROOM SHOULD BE 40

SQUARE METRE ( 6.3MT X 6.3 MTS ) 400 SQ.FT.( 20 X20

FEET)

3. THE CLASS ROOM SHOULD DERIVE THEIR MAIN LIGHT

FROM NORTH. WINDOWS SHOULD BE PLACED AT REGULAR

DISTANCE SO TO ENSURE UNIFORM OF LIGHT.

4. THE TOTAL WINDOW AREA SHOULD BE1/5TH OF FLOOR

AREA AND AT LEAST ½ OF THESE SHOULD ON THE NORTH .

5.SKY LIGHT SHOULD NEVER BE PROVIDED.

6. IF THERE IS DEFICIENCY OF LIGHT , NORTH LIGHT

SHOULD BE PROVIDED.

7. WHEN THE SCHOOL BUILDING IS ON A NARROW STREET

AND TALL BUILDING S ARE EXISTING ON THE OPPOSITE

SIDE , THE LIGHT OF SCHOOL CAN BE IMPROVED BY

FREQUENTLY WHITEWASHING THE WALLS TO REFLECT

LIGHT.

LIGHTING OF UNDERGROUND AREA (BASEMENT):

IN CASE OF UNDER GROUND CELLARS ,

PRESSED GLASS BLOCK SHOULD BE FIXED IN THE

FLOORING COMING OVER THE BASEMENT SO

THAT THEY PRODUCE CONDITIONS OF ALMOST

BROAD DAY LIGHT IN BASEMENT ROOMS BELOW

THE STREET LEVEL.