VISIBLE PERCEPTION OF LIGHT
Many people, who see induction lights, comment on how bright they appear and on what they feel is a higher quality of light being emitted from the fixtures. However, when individuals compare a induction light to a conventional lamp with a light meter, the Induction lamp is generally measured as producing less light than the conventional lamp. This has led some people to question the installation of these fixtures - even though they use 50% less energy - as they expect that the areas lit by them will not be bright enough when compared to conventional lighting. All this, even though their eyes are telling them they are the same if not brighter.
The issue is not with the induction lights and their ability to produce acceptable light. Today's standards for light meters are calibrated using the 1951 CIE Color Space Standards. They have not evolved with advancing technology in the lighting arena. This standard used to set the sensitivity curve for light meters does not take into account the contribution of Scotopic vision (night vision) to the sensitivity of the eye. Scientific studies have shown the eye is more sensitive to blue wavelengths than the measurement curve of the light meter. Blue light, acting on human night vision (scotopic vision) is largely responsible for "visual acuity" or sharpness of vision. Simply put, light meters and the 1951 standards by which they measure light are wrong. Consumers are therefore paying for products with yesterday's lighting quality while not taking advantage of today's products, such as induction lighting that offer reduced costs and a better quality of light.
VISION PARTICULARS
The human retina contains about 125million rod cells and 6 million cone cells. These respond to different frequencies (colors/ wavelengths) of light in different ways. Cone cells are adapted to detect colors and function well in bright light, while rods cell are more sensitive but do not detect color well as they are adapted to low light.
Photopic Vision is the scientific term for human color vision under normal conditions during the day (i.e. human perception of red, green and blue that the brain integrates to form full color images of the world around us.)
Scotopic Vision is the scientific term for human visual perception in low light (night vision).
Mesopic Vision is the scientific term for the combination between Photopic and Scotopic vision taking into account the total sensitivity of the rod cells in the eye for the blue range, with the color perception of the cone cells.
The ratio of Photopic light vs. Scotopic light in a lamp is called the S/P ratio. This ratio determines the apparent visual brightness of a light source. This is why the 200w lamp will appear as bright or brighter to the human eye than a sodium vapor or metal halide of twice the wattage.
The difference between the light sources becomes clear on superimposing the previous sensitivity curve on the emission spectrum of different lamps. The shaded portion shows the effective useful scotopic component of the emitted light. In other words, more the shaded area, more the visibility for that particular source.
How does it work?: Light is measured in Lumens (Lux or foot Candles). The S/P ratio of a lamp is important as it provides a number that can be used to multiply the output reading of a lamp using a 1951 standard conventional meter to determine how much light, which is useful to the human eye, a lamp produces. These are known as Pupil Lumens (PpLm)
Using a conventional light meter or spectrometer, the light is measured to determine the photopic vision sensitivity curve. Using the same light source with a light meter calibrated to the scotopic, the scotopic sensitivity curve is determined. The resulting readings form an S/P ratio that can be expressed as a Single number.
The chart below gives a comparison of Karee Induction Lamps S/P ratio compared to other common industrial lamps. These figures are based on Data received from Francis Rubenstein of Berkley National Library, with the Induction sources marked by arrows.
For Example:
An induction lamp has an S/P ratio of 2.25 for 6500k colour temperature. Accordingly for a 120W induction lamp which has a rated lumen output of 9600 Lumens, the Pupil Lumens would become 9600 x 2.25 = 22950... This gives equivalent visible light compared to a 250 W Metal Halide.
| Comparison of Electrical Consumption and Light Output | |||
| Lighting Fixture Type: | Metal Halide | 200W Induction | 120W Induction |
| Lamp Type: | M250 | 200R | 120R |
| Nominal wattage (Watts):> | 250W | 200W | 120W |
| Total actual wattage (Ballast included): | 275W | 204W | 122.4W |
| Ballast overhead (Watts): | 25W | 4W | 2.4W |
| Conversion efficiency (Lumens/Watt): | 61.8 L/W | 81 L/W | 80 L/W |
| Light output (Lumens): | 15450 L** | 16800 L | 9600 L |
| S/P Ratio (as per data from Lawrence Berkley National Library): | 1.49 | 2.25 | 2.25 |
| Output corrected for Pupil-Lumens (Lumens): | 23,020 L | 38,250 L | 21,600 L |
| Approximate light output increase/decrease (%) | 0% (base) | + 66.1% * | -6.1% * |
| Energy savings (Watts - %): | 0W – 0% | 71W – 25.5% | 152.6W – 55.5% |
| * Note: A difference of +/- 10 to 15% in light levels is barely perceptible to the human eye - % figures rounded up/down to one decimal place. ** Lumen depreciation in Metal Halide lamps not taken into account. | |||
From, the above it is clear that a 250 W Metal Halide fixture can easily be replaced with a 120W Magnetic Induction Lamp Fixture thereby, reaping a considerable saving in energy costs, while maintaining a similar light level.
For an installation having 100 lights the saving would be 15.26 KW. For a 10 Hours burning cycle and power tariff of Rs. 6 /- approx., the savings per day would be Rs. 916 /- (approx.) giving an annual savings of Rs. 3.35Lacs (approx.)
In addition savings would accrue due to nil replacement cost in the case of Induction Lamps whereas Metal Halide fixtures would need lamp / choke replacements regularly.
Comparative Matrix
| Lamp/Ballast Type | Wattage | P.F | System Wattage | Lamp Life | CRI | Mean Lumens | S/P Ratio | Mean Pupil Lumens |
| High Pressure Sodium | 70 | 0.85 | 82 | 10,000 | 21 | 5,670 | 0.62 | 3,515 |
| High Pressure Sodium | 150 | 0.85 | 176 | 10,000 | 21 | 14,000 | 0.62 | 8,680 |
| High Pressure Sodium | 250 | 0.85 | 294 | 10,000 | 21 | 25,600 | 0.62 | 15,872 |
| High Pressure Sodium | 400 | 0.85 | 471 | 10,000 | 21 | 45,000 | 0.62 | 27,900 |
| Induction | 40 | 0.98 | 41 | 1,00,000 | 85 | 3,400 | 2.25 | 7,650 |
| Induction | 60 | 0.98 | 61 | 1,00,000 | 85 | 5,100 | 2.25 | 11,475 |
| Induction | 80 | 0.98 | 82 | 1,00,000 | 85 | 6,800 | 2.25 | 15,300 |
| Induction | 100 | 0.98 | 102 | 1,00,000 | 85 | 8,500 | 2.25 | 19,125 |
| Induction | 120 | 0.98 | 122 | 1,00,000 | 85 | 9,600 | 2.25 | 21,600 |
| Induction | 150 | 0.98 | 153 | 1,00,000 | 85 | 12,750 | 2.25 | 28,688 |
| Induction | 200 | 0.98 | 204 | 1,00,000 | 85 | 16,800 | 2.25 | 37,800 |
| Metal Halide | 150 | 0.85 | 176 | 3,000 | 65 | 11,300 | 1.49 | 16,837 |
| Metal Halide | 250 | 0.85 | 294 | 3,000 | 65 | 17,000 | 1.49 | 25,330 |
| Metal Halide | 400 | 0.85 | 471 | 3,000 | 65 | 28,800 | 1.49 | 42,912 |
| LED | 40 | 0.98 | 41 | 60,000 | 65 | 3,400 | 1.85 | 6,290 |
| LED | 60 | 0.98 | 61 | 60,000 | 65 | 5,100 | 1.85 | 9,435 |
| LED | 80 | 0.98 | 82 | 60,000 | 65 | 6,800 | 1.85 | 12,580 |
| LED | 100 | 0.98 | 102 | 60,000 | 65 | 8,500 | 1.85 | 15,725 |
| LED | 120 | 0.98 | 122 | 60,000 | 65 | 10,200 | 1.85 | 18,870 |
| LED | 150 | 0.98 | 153 | 60,000 | 65 | 12,750 | 1.85 | 23,588 |
| LED | 200 | 0.98 | 204 | 60,000 | 65 | 17,000 | 1.85 | 31,450 |
Light source at a glance
Highlights of Induction Lamps:
. Long lifespan due to the absence of electrodes (filaments).
. Very high energy conversion efficiency of between 62 and 90 Lumens/Watt [higher power lamps are more energy efficient].
. High power factor (>0.98).
. Very low "ballast overhead" of the high frequency electronic ballasts which are typically between 95% to 98% efficient.
. Minimal Lumen depreciation (declining light output with age) compared to other lamp types as filament evaporation and depletion is absent.
. "Instant-on" and "hot re-strike", unlike most HID lamps used in commercial-industrial lighting applications (such as mercury-vapour lamp, sodium-vapour lamp and metal halide lamp).
. Environmentally friendly as induction lamps use less energy, and use less mercury per hour of operation than conventional lighting due to their long lifespan. The mercury is in a solid form and can be easily recovered if the lamp is broken, or for recycling at end-of-life.
KIL ELECTRONIC BALLAST
Common Ballast Specifications:-
| Input Voltage | : | 140VAC-280VAC | ||||
| Case Temp. | : | 65°C | ||||
| Input Frequency | : | 45 to 60Hz | ||||
| Operating Temp.(Open Fixture) (Closed Fixture) |
| |||||
| Output Frequency | : | 220KHz ± 5% | ||||
| THD | : | : 10% | ||||
| Power Factor | : | 0.96 | ||||
| Input current Crest factor | : | 1.6 | ||||
| Constant Wattage Output | : | ± 10% | ||||
| Input Current ratings: | : | |||||
| Wattage (watts) | 40 | 60 | 80 | 100 | 120 | 200 |
| Input Current (amperes) | 0.32-0.16 | 0.58-0.21 | 0.68-0.28 | 0.86-0.36 | 1.02-0.43 | 1.72-0.73 |
Environmental Aspects - Mercury Utilization
Almost all modern high output light sources depend on using mercury inside the lamps for operation. When considering the environmental impact of the mercury in lighting, we must take three factors into consideration:
. The amount of mercury present in a particular type of lamp, and
. The lifespan of the lamp which will determine the amount of mercury used per hour of operation.
Mercury can be compounded with other metals, into a solid form called an amalgam - this is the type of mercury used in induction lamps. The solid form of mercury poses much less of an environmental problem than liquid mercury. The amalgam form of mercury is also less of a health hazard as it is not as readily absorbed into the skin (than the liquid form) should one come into contact with the amalgam - it has low "bio-availability".
The amount of mercury varies by lamp type and manufacturer. For a 100W KIL, the net mercury content is 6.4mg.
However, in KIL, the net amount of mercury utilised per 20,000hrs of operation is approximately 1.3mg only. This in turn translates to 1,00,000hrs of operation.
Thus, in case recycling of a broken lamp, a large part of the mercury amalgam can directly be re-used in the manufacture of a new Induction tube.
Light Emitting Diodes (LEDs) & Mercury:
The latest technology generating "buzz" in the commercial/industrial lighting market is LED lighting. While LEDs are often touted as being more environmentally friendly because they consume less power than conventional HID lighting, and do not contain any Mercury, they none the less have toxic hazards of their own:
. LEDs do not contain mercury, but they do contain small quantities of other toxic substances, or substances that can contaminate the environment or groundwater such as arsenic, copper, nickel, lead, iron, and silver. In addition, toxic chemicals are used in the manufacture of LEDs which can pose an environmental hazard if not properly disposed of by the manufacturer.
. The largest component of most LEDs is plastic followed by metal. While the metal could be recycled, it is usually in such small quantities, that separating it from the other components is not cost effective. Thus used LEDs are not usually recycled and land up in the waste stream or landfills. While the amount of toxic material in each individual LED is small, they are usually used in arrays thus large numbers of LEDs are finding their way into the waste stream.
Induction light manufacturer in USA http://www.getdeco.com/induction/intro/
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