Purpose & Benefits of good lighting

Purpose of LIGHT

• To see the object.
• To decorate the object for marketing

 One of the earliest applications of electricity was LIGHTING. When light is economical and optimum, it becomes ‘Engineered Lighting’. It gives comfort and enhances safety. When light falls on an object, it is said illuminated. A viewer may be in the dark, but object must be in light, if he wants to see the object.

Benefits of good Illumination.

• It keeps the vision healthy by reducing strain on the eyes of person. Poor lighting can not only affect the health of people at work causing symptoms like eyestrain, migraine and headaches, but it is also linked to Sick Building Syndrome in new and refurnished buildings. Symptoms of this include headaches, lethargy, and irritability and poor concentration.
• It increases safety and reduces accidents. For safety of everyone using   the workplace, good lighting is essential. The quicker and easier it is to see a hazard, the more easily it is avoided. The types of hazard present at work therefore determine the lighting requirements for safe operation
• It recovers cost by increased efficiency, improved output & productivity. It is proved that Good lighting at work can reduce significant cost to business in the form of:

     – Reduction of time off work as a result of accidents and injuries;

     – Reduced absenteeism;

     – Increased staff efficiency and productivity.

     – Increase in quality product percentage of articles produced

Principle of Good Illumination

Good light can give comfort to human being. But, wrong selection of light, poor light or excessive light, glare, frequent flickering etc. are harmful to eyes. Following points are important for artificial lighting.

Adequate illumination

Level of illumination should be adequate for particular application. 6.2.3 (Table-1 & 2) shows illumination levels for various locations & applications.

To ensure lighting is suitable and sufficient, several aspects of lighting and the workplace need to be considered. These include:

• Lighting design;
• Type of work;
• The work environment;
• Health aspects;
• Individual requirements;
• Lighting maintenance, replacement and disposal;
• Emergency lighting.

Good light can give comfort to human being. But, wrong selection of light, poor light or excessive light, glare, frequent flickering etc. are harmful to eyes. Following points are important for artificial lighting.

• Level of illumination should be adequate for particular application. (Refer Table-1 & 2 for illumination levels for various applications)
• Luminaries’ selection should be according to application. User enjoys the effect of lighting and not source.
• Right selection of lamp & luminaries (combination) to suit the environment and task.
•  Mounting height & location should be such that it will not give direct or indirect glare. Glare can cause headache, eye fatigue and unpleasant working conditions.

Glare, shadow, contrast & color effects

   (a) Glare:

Glare occurs when one part of the visual field is much brighter than the average brightness to which the visual system is adapted.

When there is direct interference with vision the condition is known as disability glare. Where vision is not directly impaired but there is discomfort, annoyance, irritability or distraction the condition is called discomfort glare. The latter is related to symptoms of visual fatigue. Both types of glare can arise from the same source.      

       Glare from lighting source makes working conditions unpleasant. It also     causes fatigue and headache. When the light source is in the field of view, its glare is called ‘Direct Glare’. When glare is caused by reflected light, it is called ‘Indirect Glare’.          

 It is very difficult to read or perform any task under glare, when the image of the light source is reflected into the eyes from glossy surface. In long run, loss of visibility can also occur.

   (b) Shadow:

Shadow is black image of the object on the opposite side of light source. For shadow there are three things required – light source, object and surface. Strong shadows on the task disturbs during the activity. There can be more than one shadow.

For checking, place a thin object, e.g. a pen, on the work surface and note the number and strength of any shadows. There are various solutions to eliminate or to reduce shadow.

• Increase the reflectance of the room surfaces
• Change fittings or their spacing to provide a more even Lux level
• Increase number of fittings
• Provide local or task lighting.

    (c) Contrast

          When there is uneven lighting it gives the effect of contrast. Contrast can be checked as below:

• Check Lux levels across the working plane and across surrounding areas
• Check that the ceilings and walls are adequately lit
• Check spacing/mounting height ratio against manufacturer’s data

          There are various solutions to eliminate or to reduce contrast.

•  Replace failed lamps and clean fittings
•  Provide additional fittings
•  Decrease spacing between fittings
•  Change fittings to give wider light distribution and more upward light without causing glare
•  Increase the reflectance of room surfaces
•  Remove any obstructions

  (d) Color effect

    The color of light created by a light bulb effects how people and objects look. The higher the color-rendering index (CRI), the better that bulb will make objects appear. A color rendering of seventy or more is best. Another consideration is the amount of “warmth” or “coolness” of the bulb. A warm bulb gives off a yellow-white light, while a cool bulb gives off a white light on a neutral surface. Incandescent and warm fluorescent bulbs generally strengthen red, orange, yellow hues while weakening blue hues. Cool fluorescent bulbs generally strengthen orange, yellow and blue hues and weaken red hues.

      A surface lit by different artificial light sources, or by daylight under changing sky conditions, may appear to vary in color. Where color discrimination is required (as for some electrical work) this can affect safety, but with most light sources the change in color appearance is insufficient to create problems.

Under monochromatic light sources, such as low pressure sodium discharge lamps, colors will not be identifiable and a hazard may go unnoticed. At very low lux level, color vision fails and all colors are seen as shades of grey.

Stroboscopic effects

Lamps that operate from an alternating electrical supply may produce oscillations in light output. When the magnitude of these oscillations is great, machinery will appear to be stationary or moving in a different manner. This is called the stroboscopic effect. It is not common with modern lighting systems, but where it does occur it can be dangerous; so appropriate action should be taken to avoid it.

Flicker

 Light modulation at lower frequencies (about 50 Hz or less) which is visible to most people, is called flicker. The eye is particularly sensitive to flicker and it is especially detectable at the edges of the visual system’s field of view. Flicker can, depending on individual sensitivity, be a source of both discomfort and fatigue. It may even cause epileptic seizures in some people. Therefore it needs to be avoided.

Recommended values of Illumination level as per IS: 6665-1972

           (In the last column illumination level is mentioned in Lux.)

1. General Factory Area

1.1	Canteens	150
1.2	Clock Room	100
1.3	Entrances, Corridor areas	100

2.0 Factory outdoor areas

2.1

Stock yards, main entrances, exit roads, car parking, internal factory roads

20

3.0 Assembly shops

3.1	Rough works – for examples, frame assembly, assembly of heavy machinery	150
3.2	Medium work – for example, machine parts, engine assembly, vehicle body assembly	300
3.3	Fine works, for example, Radio & telephone equipments, type writer & office machinery equipments	700
3.4	Very fine work, for example, assembly of very small precision mechanisms, instruments	1500*

                      * Optical aids should be used where necessary

4.0 Boiler Houses (Industrial)

4.1	Coal & Ash handling	100
4.2	Boiler Rooms (i) Boiler fronts &  Operating areas                        (ii) Other areas	100 * 20-25
4.3	Outdoor plants  (i) Catwalks                           (ii) Platforms	20 60

                 * Supplementary local lighting required for gauge glasses and instrument panels      

5.0 Chemical Works

5.1	Hand furnaces, boiler tanks, stationary dryers, Stationary or gravity crystallizers, mechanical  crystallizers,  bleaching, extractors, percolators, Electrolytic cells	150
5.2	Controls, gauges, valves etc.	100**

                 ** Special attention should be paid to the color quality of light

6.0 Forging & foundry shops

6.1	General	150
6.2	Charging floors, tumbling, cleaning, pouring, shaking out, rough molding & rough core making	150
6.3	Fine molding & core making, inspection	300

7.0 Electrical Generating stations: Outdoor locations

7.1	Coal unloading areas	50
7.2	Coal storage areas	50
7.3	Conveyers	50
7.4	Fuel oil delivery headers	50
7.5	Oil storage tanks	50
7.6	Catwalks	50
7.7	Platforms, boiler & turbine decks	50
7.8	Transformers & outdoor switchgear	100

8.0 Electrical Generating stations: Indoor locations

8.1	Turbine Halls	200
8.2	Aux. equipments, battery rooms, blowers. Aux. generators,  Switchgear, transformer rooms	100
8.3	Boiler houses (including operating floors) platforms, coal conveyers, pulverizes, feeders, precipitators, soot blowers, slag blowers	70-100
8.4	Boiler houses & Turbine houses	100
8.5	Basements	70
8.6	Conveyer houses, conveyer gantries, junction towers	70-100
8.7	Control Rooms: (i) Vertical control panels                           (ii) Control desks                          (iii) Rear of control panels                          (iv) Switch houses	200-300 300 150 150
8.8	Nuclear reactors & steam raising plants    (i) Reactor areas, boiler galleries    (ii) Gas circulators   (iii)  Reactor charge / discharge face	150 150-200

9.0 Pharmaceutical works          

9.1	Raw  material storage	200
9.2	Control laboratories & testing	300
9.3	Pharmaceutical manufacturing: Grinding, granuling, mixing & drying, tableting, &  sterilizing & washing, preparation of solution & filling, labeling, capping, cartooning & wrapping, inspection	300
9.4	Fine chemical manufacture:  (i) Plant processing                                         (ii) Fine chemical finishing	200 300

10.0 Plastic works

10.1	Processing:
	(i) Calendaring & extrusion	300
	(ii) Molding-compression & inspection	200
	(iii) Sheet fabrication:
	1) shaping	200
	2) Trimming, machining  & polishing	300
	3) Cementing	200

11.0 Inspection shop

Inspection Shops
a)	Rough work, for example, counting, rough checking of stock parts	150
b)	Medium work, for example, ‘Go’ and ‘No-go’ gauges	300
c)	Fine work, for example, radio and communication equipments, calibration scales, precision mechanism, Instruments	700
d)	Very fine work, e.g. gauging and inspection of small intricate parts	1500
e)	Minute work, for example, very small instruments	3000 *
	* Optical aids should be used where necessary

12. Paint shops and Spraying Booths
a)	Dipping, firing, rough spraying	150
b)	Rubbing, ordinary painting, spraying and finishing	300
c)	Fine painting, spraying and finishing	450
d)	Retouching & matching	700 #

# Special attention should be paid for the color quality of light

13. Warehouses & Bulk stores
a)	Large material, loading bays	100
b)	Small material, racks	150
c)	Packing & dispatch	150

       Illumination levels for various applications

Category	Typical activity /Area	Lux level
A	Bldg entrances, parking lot	20-50
B	Dining area, inactive ware houses	50-100
C	Lobbies, active warehouses	100-200
D	Reading areas, Conf. rooms	200-500
E	Map reading, mail sorting	500-1000
F	Difficult assembly, cloth pressing	1000-2000
G	Difficult assembly, fine inspection	2000-5000
H	Precision arc welding	5000-10000
I	Cloth inspection	10000-20000

Type of lighting

Natural & Artificial, direct & indirect

     (a) Natural lighting

            We receive is from sun (during day time) or moon (during night time) However, the natural light received from moon is much low than the light received from the sun. This is because, the moon itself does not give any light, but it reflects the light it receives from the sun.

            Natural light received inside the building depends upon many factors; like color of the walls and ceiling, texture (smoothness) of walls & ceiling and the time of the day.

         Natural (sun) light shows the color of the thing as it is. This is called CRI of    100. All other sources of lights are compared with this index.

      (b) Artificial light sources are many. In today’s world, electricity is the main source of artificial lighting. Main purpose of artificial lighting is to have the lighting at required location and in required extent (illumination level).

     (c)  Direct & indirect lighting

           One can see the source in case of direct lighting: e..g. in the conference room. If there are tube lights fixed on the ceiling above the table, it gives direct light. If there is some designed made in the false ceiling anf the tube lights are installed such that one can not see the fixtures places above some projection on the four sides of wall, it is indirect lighting. Direct light may give some glare, but indirect light is smooth and does not give glare. However, lux level in case of indirect light gets reduced.

Light sources, lighting fittings and types of artificial lighting

Light can be produced from electricity in several ways. These can be broadly classified into two groups- Filament (incandescent) lamps and Electric Discharge lamps.

    (A) Filament lamp

• Incandescent lamps are the most familiar type of light source. They generate light using a thin filament wire that creates a white heat by an electric current passing through it. Filament is enclosed in an airtight glass envelope (bulb), which is emptied of air. It is filled with inert gas- Argon or Nitrogen or Krypton-which will slow down evaporation rate of filament. This will increase life and also allow operating at higher temperature.
• Incandescent lamps are all-purpose lamps and can be used for general, supplemental or decorative lighting. They provide a true to life, warm coloring with energy efficiency up to 18 lumens per watt.
• They are available in a variety of styles including standard bulbs, tubular, reflective spot and flood lamps, decorative bulbs or rough-service bulbs.
• A typical life can range from 500–1000 hours and long-life bulbs can last up to 2000 hours. Incandescent bulbs are readily available in stores, are easy to install and their life is not affected by switching them on and off.
• From electrical energy supplied to filament lamp, only 8 % energy is converted to light. This type of lamp has lowest efficiency and highest CRI (Color Rendering Index).

    (B) Discharge lamps

    While filament lamps produce light by creating heat, discharge lamps rely on light emitted by a gas or vapor. Electric current passing through it excites this medium.

 Under this principle, arc (miniature flash of lighting) is struck between two electrodes enclosed in a glass tube. It contains inert gas or vapor. Heat generated by an arc vaporizes metals, which emit their characteristic colors of light. Discharge lamps use sodium or mercury, contained in an inner arc tube through which stream of electrons passes. Metal vaporizes, becomes excited and emits radiation.

         In right applications, Discharge lamps have many advantages over filament lamps. It can radiate up to 198 Lumens/watt against 12 Lumens/watt by filament lamps. Also, life of discharge lamps is many times more. Various types of discharge lamps are as below:       

    (a) Halogen

• Halogen lamps generate light by using a thin filament wire enclosed in a quartz tube that contains a pressurized gas such as halogen, iodine or bromine. This design allows the bulb to burn hotter which produces a whiter, brighter light more efficiently than an incandescent bulb.
• Halogen bulbs are used for accent lighting, display lighting, outdoor floodlights and automobile headlights.
• They are available in a variety of styles including single and double-ended quartz, reflective spots and floods, parabolic aluminized spots, floods and mini-can bulbs.
• They have a typical life range from 2000–5000 hours. Halogens provide a brilliant white light with energy efficiency up to 22 lumens per watt. The bulbs come in compact sizes, do not blacken with use and provide an intense, focused light.

      (b) Fluorescent

• Fluorescent lamps create light by passing an electric arc through an inert gas. The heat generated from the arc vaporizes tiny drops of mercury which emit ultra-violet (UV) light.
• The released UV light stimulates a phosphor coating on the inside of the glass bulb, glowing brightly in all directions. The inert gas used is a mixture of Argon & Krypton, at very low pressure (0.0005 bar). Because of very low pressure, initial discharge does not take place when supply is switched on.
• Ballast is required to heat the bulb electrodes on initial start-up, and then regulates the power flow to keep the lamp burning.
• The starter short circuits two filaments during starting. This allows current to flow through the electrodes of the tube.
• Fluorescent lamps excel at providing high levels of general lighting very efficiently. They can last 10 to 20 times longer than an incandescent light and use one-fifth to one-third the electricity to generate the same brightness.
• They are available in several styles such as u-shaped, circular and straight tubes up to 96″ long. The typical life range is from 12,000–24,000+ hours, with an energy efficiency up to 105 lumens per watt.
• A drawback to fluorescent lights is that they can only be dimmed with expensive special equipment and are sensitive to cold temperatures.

(c)  Compact Fluorescent lamp (CFL)

• CFLs operate in a similar fashion as linear fluorescent lamps. These lamps are designed for use in standard incandescent sockets and serve as energy-saving replacements to incandescent lights.
• They are available in bulb, circular or twin-tube configurations.
• Typical life ranges from 9,000–10,000 hours with energy efficiency up to 105 lumens per watt.
• They have color similar to incandescent lights, last 9 to 13 times longer and save 64% to 82% in energy consumption compared to incandescent lights.
• To maximize the life of the bulb, compact fluorescent must be used in locations where they stay on for several hours at a time.
• Dimming is not possible in CFLs.

(d) High Intensity Discharge

• Four types of HID lighting available – HPMV (high pressure Mercury vapor), high-pressure sodium vapor (HPSV), low pressure sodium vapor (LPSV) and metal halide—all in a screw-base bulb.
• High intensity discharge (HID) lamps generate light by passing electrical current through an internal tube filled with a blend of gases under pressure.
• Electricity through the tube is regulated with ballast in similar fashion of a fluorescent lamp.
• HIDLs are powerful light sources used for general area, landscape or outdoor floodlighting.
• Typical life ranges from 10,000–24,000 hours, with an efficiency of 65 to 140 lumens per watt.
• These lamps are the most energy efficient bright lights that provide long life in hot or cold environments.
• HIDLs take a few minutes to warm up as they gradually reach full brightness.

  (C) Lamps & lighting fittings (luminaires)

The choice of lamp depends on certain factors, such as the type of workplace in which it is to be used, luminous efficiency and service life. Luminaires must:

• Support and protect the light source;
• Provide safe electrical connection;
• Be safe for installation, use and maintenance;
• Where practicable, provide filtering to remove harmful levels of radiation

Each fitting is designed for a specific lamp or range of lamps. If lamps are put in the wrong fittings, this may result in glare and decrease the life and operating efficiency of the lamp. Using fittings in situations for which they are not designed (for example, low-pressure sodium lamps in a potentially wet environment) can be dangerous.

For each application and ratings of the lamps, light fittings are available. For example, for simple location, channel mounted FL fitting is available – with one or two tube lights. But if it is conference room, many types of decorative fittings are available – for diffused lighting, indirect lighting, prismatic louvers, milky white louvers, mirror optic louvers etc.

For work shops, high bay fixtures for HPMV or Halogen lamp fixtures are used. For street light on spacious traffic circles, high masts are common, where maintenance can be done after lowering down (by winch mechanism) the cluster to the ground.

Selecting the fittings (luminaires) is highly expertise job. These are experts for lighting field, who decide location of fixtures, type, wattage, fitting types and other matters connected with energy saving also.

  Comparison of Light Sources

There are four factors by which various types of light sources are compared. These factors are as under:

• Efficacy:  Quantity of light emitted per unit power input is called EFFICACY. It is expressed in Lumens per Watt.
• Color Rendering: Degree of light source to show true color of the object is called color rendering. Its unit is Color Rendering Index (CRI). It is rated from, 0 to 100. Incandescent lamp has CRI of 100. Fluorescent lamp has CRI of 54. Low-pressure sodium lamp has CRI of zero

(c) Color Appearance: The apparent color of the light emitted from the light source is known as Color Appearance. It can be defined as Warm, Intermediate & Cold. Other way is by temperature measured in Kelvin.

(d) Lumen Maintenance: The curve showing light output against time is called Lumen Maintenance Curve. It helps to predict when output will decline to the point needing replacement.

Design of lighting installation

There are some terms connected with lighting design. These are as below;

(a) Coefficient of utilization: It is the ration of the luminous flux (Lumens) received (from the luminaire) on the working plane to the lumens emitted by the luminaire’s lamps alone.

(b) Light loss factor (also known as Depreciation factor): It is the ratio of illuminance under normal working condition to the illuminance measured when everything (lamps, luminaire etc.) is clean.

This factor takes care for dirt accumulation, lamp depreciation, temperature & voltage variation etc.

Design of lighting installations, interior and exterior, are comprised of a lamp(s), a luminaire, and a control system. The amount of light on a surface affects our ability to see. The finer the detail, the higher the illuminance required. What are the basic requirements of good lighting system design?

• Lighting should be uniform on the surface or working area
• Lighting design should take account of the effect of shadows cast, whether these are objects and/or people in the work environment.
• Light sources should be positioned to minimize these effects. For example, it is not good practice to illuminate machinery or a protrusion from below, as the shadows may lead to confusion and an accident.

  The type of lighting installation chosen depends on:

• Its suitability for use;
• Whether it is safe for use;
• The size of area to be covered;
• The physical constraints of the space;
• The purpose for which it will be used.

Following data is required for designing lighting system:

• Layout & cross section elevation
• Color and texture of walls
• Equipments & machine layout
• Air conditioned or not

Selection of source depends upon:

• Area to be lighted
• Mounting height
• Efficient operating time
• Dimension of source
• Color appearance
• Brightness  

Interior lighting

Interior lighting can be split into three categories:

• General;
• Localized;
• Local.

General lighting provides uniform illumination over the whole working area and does not limit positioning of the work. Localized lighting provides different levels of illumination in different parts of the same working area. It matches the level of illumination to the needs of specific tasks. Local lighting is usually a combination of background lighting and a luminaire close to the actual work area. It is used when:

(a) A high level of illumination is needed in a small area;

(b) Flexible directional lighting is required, for example when doing different tasks at a workstation;

(c) General lighting is unnecessary or impossible to install because of the layout of the work area

Choosing lighting is a matter of judgment. There is no single best approach. However, the lamp and the luminaire need to be selected as a package, because each luminaire is designed for a limited range of lamps.

    If a group of luminaires is selected, the spacing between them needs to be considered. Manufacturers publish maximum spacing/mounting height ratios for each luminaire. If these are exceeded there will be excessive variation in illuminance across the working plane.

Where illuminance on vertical surfaces is important, it may be necessary to space the luminaires closer together than the maximum spacing/mount ratio given by the supplier, to ensure that the illuminance is evenly distributed across all vertical surfaces.

      However, placing luminaires closer together need not apply where there is a regularly arranged obstruction, for example in works stores. In this case the spacing between fittings needs to match the spacing of the obstruction.

       Where linear luminaires with tubular fluorescent lamps are used, the position and angle of the luminaire must be considered, as well as spacing. Such luminaires are less glaring if viewed end-on, rather than sideways-on. A regular arrangement of luminaires should therefore be positioned so that they are end-on to the viewing direction with the longest dimension. Corridors are an extreme example; it is generally better to align linear luminaires along the corridor rather than across it.

       The position of local luminaries is important as it determines both the illuminance on the workstation as well as the degree of glare.

Exterior lighting

In general all exterior installations should:

• Achieve a reasonably uniform illuminance on all relevant work areas;
• Avoid glare to the users of those areas and to occupants of nearby areas.

Illuminances provided need to be consistent with the lighting recommendations suggested in this guidance. To avoid excessive contrast in illuminance, luminaires should not be spaced too far apart. This is important in security lighting where a variation in light levels may pose a safety risk. Glare is determined by the light distribution of fittings, their mounting height and, for floodlights, the direction of aiming.

With large areas, the lighting design chosen depends upon:

• The degree of obstruction;
• Whether illuminance is required primarily on horizontal or vertical planes.

Where obstruction is likely and where illuminance on the horizontal plane is important, for example in lorry parks, lighting should be overhead from a height that minimizes shadows.

    If obstruction is slight and vertical illuminance is required, floodlighting projectors can be used. However, care needs to be taken to avoid glare. When choosing the mounting height of luminaires, the following should be considered:

• Cost;
• Planning laws;
• Positions where poles/towers can be placed;
• Level of glare that is acceptable;
• Ease of maintenance required.

For internal private roads, the road surfaces and surroundings need to be lit to enable vehicles and objects to appear in silhouette.

Lighting that gives good color definition also enables pedestrians to identify other people and/or vehicles clearly.

      Where the periphery of a building is to be lit, wall-mounted fittings may be used. These can be simple projector floodlights or bulkhead fittings, provided they are suitable for external use.

       Wall-mounted, pole-mounted, or bollard-type fittings can be used for entrance areas. Again, spacing and light distribution determines the uniformity of illuminance. Fittings need to be carefully chosen to minimize glare for people entering or leaving the building.

       Outside workplaces (especially construction sites) tend to have temporary lighting installations and portable lighting, including hand lamps. The lighting objectives for temporary installations should be the same as for permanent ones, although the extra wear and tear on temporary equipment will have safety implications for the choice of equipment, the means of fixing and the source of electricity.

For designing of road lighting following data is required

• Type of road surface
• Road width
• Mounting height (of fixture)

                   Table- 1   COMPARISION OF VARIOUS TYPES OF LAMPS

Type of lamp	Luminous Efficacy (Lumens per watt)	Color Rendering Index ( CRI )#	Average Life in Burning hours	Restriking time
Low pressure sodium vapor	120	0	18000	12 min.
High        —–do ———	120	23	15000	1 min.
Fluorescent Tube ( Tri band)	90	86	14000	2.4 sec.
Compact  Fluorescent Tube	80	54 – 82	7500	2.4 sec
Metal Halide	80	95	10000	4 min
HPMV	54	46	5000	1 min.
Fluorescent Tube	60	60 – 92	5000	2.4 sec
Halogen	22	100	2000	0
Mixed Light Lamp (MLL)	20	52	3000	0
GLS (filament)	18	100	1000	0

# – CRI scale is 1 to 100

Table- 2  LUMEN OUTPUT COMPARISION OF VARIOUS TYPES OF LAMPS

		Lamp output (in Lumen) for different types of lamp
Type of lamp è		fila.. lamp	HPMV lamp	HPSV lamp	LPSV lamp	Fluore.  lamp	CF lamp	Halogen lamp
11 W							900
20 W						970	1200
25 W		230
35 W					4600
40 W		415				2550
60 W		710
70 W			5800
100 W		1380
125 W			5800		22000
150 W		2060		15000
250 W			12500	25000
300 W		4800						4800
400 W			22500	47000
500 W	8200							8700
1000 W		18400	55000

Effects of color on safety

Colors to identify hazards

1.0 Color code for pipelines according to IS: 2379 – 1963

Identifications: The system of color coding consists of ground color and color band

superimposed on it.

                   Table-1 Distinct shades of colors to be used for coding

Color	Shade no. & its description (According to BE:5-1961)
Black	Black (Not included in IS: 5 -1961)
Blue	01  Sky blue
	66  French blue
Brown	410 Light brown
Green	217 Sea green
Gray	628 Silver grey
	631 Light grey
Orange	557 Light Orange
Red	536 Fire red
	537 Signal red
Violet	796 Dark violet
Yellow	309 Canary yellow
	397 Jasmine yellow
	356 Golden yellow
White	White (Not included in IS: 5 -1961)

      There are two types color coding. One is ground color and other is color band.

   2.0 Ground color:

The ground color identifies the basic nature of the fluid carried and also distinguishes one fluid from another, e.g. water from solvent. Various ground colors as included in this standard are explained in Table-2

Table-2 Ground color of the pipeline

Color	Substance
Sea Green	Water
Light brown	Mineral, vegetable and animal oils: Combustible liquids
Dark violet	Acid & alkalis
Silver grey	Steam
Sky blue	Air
Black	Other liquids
Canary yellow	Gases

      3.0 Color Bands

3.1 Color bands are superimposed on the ground color to distinguish

• One kind or condition of a fluid from another kind or condition of same kind of fluid e.g. pure or impure material or
• One fluid from another but belonging to the same group. For example, CO from coke oven gas or diesel fuel from furnace fuel.

     3.2   Guidelines of color bands

• Color band shall be arranged in the sequence shown (in Table-3) as per IS 2379 and the sequence follows the direction of flow
• Wherever two color bands are applied, the relative proportional widths of the first color band to the second bend shall be 4:1

         (c) As a rule, minimum width of color band shall confirm to the Table 4

Table-3 Color code for general services

Type of content	First color band	Second color band
1. Water ( Ground color – Sea green)
Cooling	French Blue	X
Boiler feed	X	X
Condensate	Light brown	X
Drinking	French Blue	Signal Red
Treated	Light orange	X
Central Heating < 60 degree C.	Canary yellow	X
Central Heating  60 to 100 d. C.	Dark violet	X
Central Heating > 100 d. C.	Dark violet	Signal Red
Cold water from storage tank	French Blue	Canary yellow
Domestic, hot	Light gray	X
Hydraulic power	Black	X
Sea, river, untreated	White	X
2. Compressed air (Ground color –  sky blue)
Up to 15 bar	X	X
Above 15 bar	Signal Red	X
Vacuum	Black	X
3. Steam (Ground color – Silver grey)
4. Drainage (Ground color -Black)
5. Town gas ( Ground color – Canary yellow)
6. Oils (Ground color- light brown)
Diesel fuel	Brilliant green	X
Furnace fuel	French blue	X
Lube oil	Light gray	X
Hydraulic Power	Dark violet	X
Transformer oil	Light orange	X
7. Fire services – Ground color – Fire red

Table 4 First color band width

Nominal pipe size*	Width L (of color band)
80NB & below	25
Over 100 NB up to 150 NB	50
Over 200 NB up to 300 NB	75
Over 350 NB	100

* For insulated pipes, nominal pipe size means the outside diameter of insulation

   3.3 Color Bands shall be superimposed on ground color at the following locations.

• At battery limit points
• Intersection points and change of direction points in the piping ways
• Other points such as midway of each piping way, near valves, junction joints, walls, on either side of pipe culverts
• For long piping at 50 Mt interval
• At start & terminal points

Lettering & direction of flow:

       The recommended size of lettering for pipes of different diameters is given below in Table-5

Table-5 Size of lettering

Outside diameter of pipe (in mm)	Size of legend (in mm)
20 to 30	10
Above 30 up to 50	20
Above 50 up to 80	30
Above 80 up to 150	40
Above 150 up to 250	63
Above 250	90

Whenever it is required to indicate the direction of flow, arrows or letters may be painted near valves, junctions, walls etc., at suitable points along the pipeline. These shall be black or white in color and in contrast to the color on which they are superimposed.

Valves shall be painted with the same color as the main pipelines except when the pipeline has been provided with the safety color, the valves shall be painted red for fire fighting, yellow with black diagonal stripes for warning of danger and French blue in conjunction with the green basic color to denote pipes carrying fresh water, either potable or non-potable.

All uninsulated pipes having temperatures above 100 degree C. (heat resistance Aluminum painted) need not be identified with color bands. As a special case, if required, color bands may be applied using Teflon tape.

Safety color code for Industrial gases

Table- 6 Color code for Industrial gases

Gas	Ground color	First color band	Second color band
Ammonia	Dark violet	X	X
Chlorine	Dark violet	Signal blue	X
Hydro cynic Acid	Dark violet	French blue	X
Phenol	Dark violet	Canary yellow	X
Sulphur Dioxide	Dark violet	Brilliant green	X
Acetylene	Canary yellow	Dark violet	X
Argon	Canary yellow	French blue	X
Benzole	Canary yellow	Dark violet	French blue
Blast furnace gas	Canary yellow	Signal red	Light grey
Butane	Canary yellow	Signal red	X
Coal Gas	Canary yellow	Signal red	Brilliant green
Carbon dioxide (Temperate)	Canary yellow	Light grey	X
Carbon monoxide	Canary yellow	Signal red	White
Coke oven gas	Canary yellow	Signal red	Dark violet
Ethyl chloride (inflammable)	Canary yellow	Light grey	Signal red
Ethyl chloride ( non-inflammable)	Canary yellow	Light grey	White
Ethylene	Canary yellow	Dark Violet	Signal red
Ethylene oxide	Canary yellow	Dark Violet	Brilliant green
Helium	Canary yellow	Light brown	Dark violet
Hydrogen	Canary yellow	Signal red	French blue
Methane	Canary yellow	Signal red	Light brown
Methyl bromide	Canary yellow	French blue	Black
Methyl chloride (Inflammable)	Canary yellow	Brilliant green	French blue
Neon	Canary yellow	Light brown	Black
Nitrogen	Canary yellow	Black	X
Oxygen	Canary yellow	White	X
Propane	Canary yellow	Signal red	Black
Phosgene	Canary yellow	Black	White

Indian standards

IS: 02206-01(1984) – FLP Lighting fittings: Well glass & Bulkhead

IS: 02206-02 (1976) – FLP Lighting fittings: Fittings using glass tubes

IS: 03646-01(1992) – Code of practice for interior illumination: General requirements& recommendations for working interiors

IS: 03646-02(1966) – Code of practice for interior illumination: Schedule of values for illumination & Glare index

IS: 03646-03 (1966) – Code of practice: Calculation of co-efficient of utilization by BZ method

IS: 06665 (1972)      – Code of practice for industrial lighting

IS: 04347 (1967)      – Code of practice for hospital lighting

IS: 02672 (1966)      – Code of practice for library lighting

IS: 01944 – 01 & 02 (1970) – Code of practice for lighting of Public thoroughfares

Accident Prevention sign

Safety color code for signs & equipments

Table -7 Safety color code

Color	System / equipments
Dark Red	Fire alarm boxes, Fire protection equipments & apparatus, fire blanket boxes, Fire hose-locations, Sprinkler piping etc., Stop sign, Stop push buttons, Danger, Safety cans & other containers for flammable liquids, red lights at barricades.
Orange	Basic color for designating dangerous parts of machines or equipments. Transmission guards for gears, pulleys, chains, etc., Safety starting PB, Exposed parts of pulleys, gears, power jams, etc,
Yellow	Basic color for designating caution :To mark aisles & direct flow of traffic, Construction equipments such as bulldozers, tractors, Handrails, guardrails, barricades, markings for low beams, pipes, projections.:
Green	Basic color for designating safety and location of first aid equipments. Safety bulletin boards, First aid kits, Stretchers, Personal protective equipment supply cabinets
Blue	Basic color for designating machine & equipment controls:                                               Electronic controls, valves, Brakes, Disconnects.
Purple	Basic color for designating radiation hazards: Radiation warning                                                                                        signs, Containers of radio active materials, signal lights to indicate radiation machines are in operation.
Black, white or combination	Basic color of housekeeping markings. Stairways risers, Location of refuse cans, Food dispensing equipment, Passageways.

Psychological Effects of Color

1.0 Color affects every moment of our lives although our color choices are mostly unconscious. Color has a great emotional impact on a person that comes out via the clothes we chose to wear, decorations to fill our homes, personality, foods we choose to eat and many more ways.

             The human eye can see 7,000,000 colors. Some of these are eyesores. Certain colors and color relationships can be eye irritants, cause headaches, and wreak havoc with human vision. Other colors and color combinations are soothing. Consequently, the appropriate use of color can maximize productivity, minimize visual fatigue, and relax the whole body.

    It is possible to introduce colors to different areas of daily life to give off more energy, soothing affects, stimulate appetites and sexual motivation or even give a place a clean atmosphere. I asked thirty males from the ages of fifteen to sixty what color bra they would like to see their dream girl wearing to find out what colors are the most sexually stimulating. As I predicted, out of thirty, fourteen chose black, while four chose pink, red, blue and white were also chosen by three each and gray and purple were each favored by one person a piece. I also conducted an experiment to see what colors were stimulating on appetites. I added food coloring to make one flavor of Jell-O turn red, orange, yellow, green, blue, purple, brown, and pink. Out of fifteen total people, seven chose red, purple and pink were chosen by three a piece, and orange and green were chosen by one each.

     Red

• Red, having the slowest vibration, acts on the emotions quicker than any other color.
• It is, almost universally, the color of passion and warmth but in its deeper shade of scarlet, red can instigate the beast in man.
• It stands for all the vigor and excitement in life, and induces feelings of strength and vitality in a person.
• The unfavorable influence of red can trigger off strong emotions, not only of fear and anger but also of irrepressible lust.
• In its crimson shade, the color denotes the painful aspects of life, whereas the pink shade evokes maternal affection.
• Red can be used in treating irregularities in blood circulation, but it is not very conducive to people who suffer from mental maladies

Orange

• Orange is a strong stimulant for ambition, and also motivates ones’ creative pursuits.
• It not only engenders a sense of self-esteem but also fosters a sense of preservation of fellow creatures.
• Prolonged exposure to orange can be a cause of restlessness and nervous breakdown.
• Orange, being the color of many fruits and vegetables, stands for nourishment.
• Orange is a strong stimulant for ambition, and also motivates ones’ creative pursuits.
• It not only engenders a sense of self-esteem but also fosters a sense of preservation of fellow creatures.
• Prolonged exposure to orange can be a cause of restlessness and nervous breakdown.
• Orange, being the color of many fruits and vegetables, stands for nourishment and also represents the attractive force between elements.

Yellow

• Primarily a cheerful color, yellow brightens up the room and signifies wisdom and jubilation.
• Golden yellow, which stands for peace, compassion and creativity, inspires spiritual elevation.
• In its negative aspect, exposure to very bright yellow can lead to an over stimulation of the psyche which could then have disastrous consequences.
• Yellow fruits and vegetables generally act as laxatives to the bowel and also soothe the nerves.

      Green 

• The various shades of green are the joyous colours of nature.
• Green is the invigorating touch, especially for those suffering from mental fatigue.
• Green represents jealousy in its negative aspect, with darker shades tending to be extremely depressing.
• While yellow-green stimulates generous feelings, spring green heralds new life.

     Blue

• Majestic blue is the color of heavenly consciousness, of truth and cosmic harmony.
• Blue evokes a sense of sublime calm, and as opposed to red, it tends to quite passion.
• Soft blue clothing, besides preventing a tan in women, can arouse the protective instinct in men.
• Blue and green when combined can favor a prolific outburst of creativity.
• Too much of blue on the other hand could be a depressing influence.

    Indigo

• Indigo partakes of both blue and violet, and represents a combination of disciplined rationality and creative intuition.
• It resembles, not only the duality of the human metabolic process, but also the natural law of growth and change.
• Fruitless endeavors and consequent stagnation represent some of the unfavorable aspects of indigo.
• It acts as the threshold of success that comes after a period of failure, and in that it represents the healing crisis of the natural healing art.

      Violet

• Violet being the fastest vibration in the spectrum is also the quickest one to disappear.
• Traditionally a symbol of regal splendour and spiritual authority, violet is associated with wealth and fecundity.
• Violet, in its positive aspect, appeals to the higher faculties of man – mastery over ones’ self, search for truth and creativity.
• If violet stands for honor on the one hand, it can also denote deceit on the other, and one can easily be taken in by its pretence.

     White

• White, being the perfect blend of all the colors of the spectrum, is the touchstone of purity and harmony.
• It is averse to all the lowly traits in man – malice, deceit, envy and violence, and always favors the revelation of truth.

    Gray

• It is the color of individuals.
• It gives off the impression that you are self-sufficient and have good self control and prefer to be uninvolved.
• Gray is associated with independence, self-reliance, and acts as a shield from influence.
• However, gray gives off a negative feeling and can make a person who is around this color frequently, feel lonely and self critical.
• Gray takes on many of the characteristics of black and white since it is a combination of the two.

    14.0 In the end, color subconsciously plays a vast role in the psychology of humans. It can be a major persuasion factor in our emotions, and they can seriously uplift or bring us down, especially if a person associates a color with one particular idea. However, naturally, color has the same general affect on people.

               Colors are of philosophical interest for two kinds of reason. One is that colors comprise such a large and important portion of our social, personal and epistemological lives and so a philosophical account of our concepts of color is highly desirable. The second reason is that trying to fit colors into accounts of metaphysics, epistemology and science leads to philosophical problems that are intriguing and hard to resolve. Not surprisingly, these two kinds of reasons are related. The fact that colors are so significant in their own right, makes more pressing the philosophical problems of fitting them into more general metaphysical and epistemological frameworks.

15.0  Principles about Appearances and the Perception of Color:

• Specific colors have distinctive appearances, characteristic of each color.
• The way colors are identified and recognized is by the way they appear to perceivers. There are no color thermometers or other measuring devices.
• Colors take a different mode of appearance, i.e., have a different characteristic appearance, when they are features of physical surfaces, films, volumes, light sources, etc.
• There are principles governing the conditions under which colors are perceived. Certain conditions are better than others for identifying colors; certain people are better than others at identifying colors. Colored bodies can appear differently when viewed at different distances, in different illuminations, and against different backgrounds.
• Among the principles in A4 are principles governing constancy effects: tendencies for objects to look the same under different conditions.

There is a certain distinctive form to the way colors appear. Visual experiences represent colors in a certain way, as qualitative features which are “sensuous” in the widest sense.

Maintenance for lighting

• Lamps/fittings need to be kept clean and replaced, as Lux levels decline with age. How often they are maintained and replaced depends on the type of lamp/fitting and the environmental conditions.
• For example, if the lamp/fitting is out of reach and therefore infrequently cleaned and is in a dirty, corrosive environment, it will need to be replaced more often than the same equipment in a typical office environment.
• Also, it is required that access to remote fittings is safe and easy, so that required activities like cleaning, repairing or replacing is regularly carried out.
• Ensure that fittings are intact and undamaged, as this may pose a health and safety risk to employees.
• Damaged fittings may expose dangerous live electrical parts. They may also present a health hazard. Information on the use of high-wattage tungsten.
•     Dispose damaged lamps/luminaires for safety. Repair or replace damaged or ineffective lamps/luminaires

Replacing lamps

• When replacing lamps in existing luminaires, care needs to be taken to ensure that the lamp and control gear are electrically and physically compatible. For example, a 110-volt lamp should not be fitted in a 240-volt light fitting.
• In addition, the overall dimensions of the lamp should be suitable for the luminaire. If they are incompatible the lamp may become damaged; or, alternatively, the lamp, luminaire, or control gear may overheat causing a fire risk.
• When carrying out maintenance, it is important to ensure that safety procedures are properly followed and do not interfere with other work activities. Planned and regular maintenance is good practice. This ensures that lighting is safe and lux levels are maintained.