Lighting

CP 87:2001 (Singapore Standard)

The code of practice focuses on the optimum performance of people in indoor industrial premises. Suitable and adequacy of lighting is essential for the safety, comfort, well being and productivity of the people working in such premises. This code provides the guidelines for lighting requirements in terms of quantity and quality of illumination, lighting systems and lighting measurement, maintenance and improvement of such customised lighting systems for various indoor industrial situations.
 
Optimal quality and quantity of lighting is emphasized. Quality of lighting may be expressed in terms of glare, brightness, color of light, direction and reflection, and other factors affecting visibility. Excessive brightness is discouraged as it is a waste of energy and money and causes eye glare under prolonged exposure. Industrial standards usually call for minimum requirements. Some of it can be applied to the standard for home lighting requirements.

Factors influencing Visual tasks are:

• The size, shape, texture of visual objects
• Contrast and color between visual objects and surroundings
• Movement and time available for viewing
• Luminance ( photometric brightness)
• The age and condition of the eyes (myopic, far-sightedness etc.)

 
Older people need brighter and better lighting than younger people. Color or brightness contrast between visual objects and the background and will affect the sharpness of vision.
 

Quality of Lighting
 
Quality of lighting affects vision, especially in inspection work, fine manufacturing, color matching and in home activity such as prolong reading, writing, needle work etc. Below are some points to consider:

Glare - Try to avoid glares. Looking at stray bright lights directed or reflected from shiny surfaces should be minimized. Relocate to an area without glare or reduce the number of lights. One example is to avoid placing the television in front of the windows or in direct reflection of windows.

Contrast, distribution & reflection: Visual sharpness is affected by the background. A uniformly lighted surrounding will produce a higher level of comfort and efficiency. Generally, the brightness of the task area should not be higher than the surrounding brightness by 3 times. Use the Eye Care LITECheck to measure and work out this factor.

Flickers - Noticeable flickers from lighting tubes can raise discomfort and cause annoyance. Flickers at certain rate can cause slow moving objects to appear to be stationary. This may pose to be a safety hazard. Flickering light tubes should be changed promptly.

The quantity of light is dependable on the task performed. Below is a summary of the brightness level required. With the use of the LITEcheck tester, the brightness level is easily measured in the unit of LUX.

The above requirements are the minimum maintenance brightness. This means light bulbs should be cleaned or replaced if they fall below these standards.

Maintenance of Lighting

Periodically checking the minimal required brightness throughout the life of light bulbs - Using the LITEcheck tester to check brightness of task area to determine if you need to shift the task area nearer to the light source or vice versa, or to perform maintenance.

Maintenance of light bulbs - All lighting bulbs or tubes will degrade the moment you install them. Because our eyes are very adaptable to the changing of light, using our eyes to judge lighting can be very misleading. Different types of lighting bulbs or tubes have varying life-span and they do not burn out immediately but degrade gradually.

Cleaning is the first step to improve brightness. Dust that accumulates on the surface of bulbs, tubes or reflector can reduce brightness substantially. Caution: Remove bulbs or tubes from the fixture and wipe only with a damp cloth. Never clean directly with the bulb or tube attached to the fixture.

If after cleaning, the brightness does not improve to the required reading, then replacing the bulbs or tubes will be necessary. Procrastination usually is at the expense of our eyes health and that of our family members or children.  

Pocket LITEcheck Meter for Light Penetration Test

Recent regulations on tinted windscreen for vehicles, requires all vehicles to meet at least 70% light penetration on the front windscreen and 50% light penetration on other windows and the rear windscreen.

With the regulations, there is an immediate need for all vehicles nationwide to be inspected and tinted windscreens replaced with the required light penetration. Trans Instruments has a pocket size tester that allows workshop technicians to perform the test in-house.

The testing procedure is simple. In a bright area but without any direct sunlight on the vehicle, switch on the meter and place it on the inside of the windscreen with the sensor facing the tinted screen. Press the ''HOLD button and record the reading of light with tinted screen as reading A. Now place the meter outside and on top of the windscreen. Press the ''HOLD'' button and record the reading of light without the tinted screen as reading B. Light penetration rate is calculated using the following formula:

 
To learn more about lighting in the Aquarium, click here!
 
To learn more about lighting in Hydroponics, click here!