Halogen Handbook

HOW TO GET THE MOST FOR YOUR MONEY ON HALOGEN LAMPS Everyone knows that the more we learn about an item, the better chance we have of saving money and becoming more efficient with our purchases. The same philosophy holds true for halogen lamps. The following literature is intended to help you learn more about halogen lamps and, hopefully, to help you save money and/or avoid pitfalls in your future purchases. HOW DO HALOGEN LAMPS WORK? The characteristics of tungsten halogen lamps that improve the lamp itself, such as its longer life, higher efficiency, compact size and reduced bulb blackening during the lamp's life, are a direct impact of the tungsten halogen cycle. To simplify the explanation of the cycle, evaporated tungsten from the bulb's filament combines with the halogen gas to form a tungsten halide. This process increases the lamp life and prevents the bulb from blackening. When this tungsten halide comes into contact with the hot filament it separates and the tungsten re-deposits back on the filament. Not all of the tungsten is able to redeposit back on the filament. This gives these lamps a finite life. The fused quartz in the halogen lamp allows it to withstand the high temperature required for this process. "130 VOLT LAMPS LAST LONGER THAN 120 VOLT LAMPS" Well, SOMETIMES! You may have been told that the 130 volt lamps have a bigger filament thus allowing them to last longer. This is true if your facility's voltage is between 122 and 130 volts. The 130 volt lamp does have a bigger filament and is designed to operate at a higher voltage. If your facility is below 122 volts you will lose efficiency, your color temperature will shift towards yellow and the lamp's expected life may be reduced. Over voltage operations result in higher wattage, higher efficiency and a higher output, but a shorter life. If you don't know what your actual operating voltage is, find out. It's really easy (give us a call and we will help). It just may be that the 130 volt lamp is the way for you to go, then again, maybe not. It is important to use the correct voltage lamp in order to get the best lamp life, color rendering, color temperature and energy savings! OK, SO WHAT IS COLOR RENDERING? The reason why halogen lamps are frequently used is because of their excellent color rendering. Color rendering is defined as a measure of lighting quality. This measure is based on an index that ranges from 1-100 with natural daylight and halogen lighting being 100 CRI (color rendering index). Objects, (such as art work, jewelry, fabrics and so forth) and people lit with halogen lamps that have a high CRI, will appear more true to life. Color of objects can be perceived more accurately under lamps with a high CRI. Another wonderful side effect of high CRI light sources is that they produce a higher perceived level of light (they look brighter) which in turn makes them more energy effective (you save money). LAMP LIFE: In order to understand lamp life you need to know how lamp life is determined. Manufacturers determine it by burning a large group of lamps continuously. During this process, some lamps will fail relatively early while others will burn long after their rated life. It is when half of this

group of lamps burn out that the manufacturer assigns "LIFE". Think of lamp life as an average. So, if you encounter a salesperson bragging about the longevity of their lamps, be wary! The laws of physics dictate that both the life of the lamp and the light output are determined by its filament temperature. Even the best salesperson cannot defy the laws of physics! Also, some offshore lamp companies are not held to the same ethics that the major manufacturers are and will not always tell the truth about the performance of their lamps. COLOR TEMPERATURE: Simply the measure of the COLOR of light. Not to be confused with COLOR RENDERING as they are not associated with each other. An example of Color Temperature is the color difference of light between the white hot light of high noon verses the warm color of light right before sun sets. The Color Rendering never changes during the day. Color Temperature is measured in Kelvin Degrees. CANDLEPOWER: The intensity in any one direction from the standard candle is called one "candela" (formally called "candlepower"). Most PAR and MR-16 lamps are measured this way. Do not confuse Wattage with the light output of a lamp; Wattage is only a measure of consumption. BEAM SPREAD: Measured in "Degrees" this is the measurement of the actual beam spread of the lamp. As an example, a 40 Degree would be considered a "Flood" whereas a 10 Degree would be considered a "Spot". DIAMETER OF A LAMP: The diameter of a lamp is measured in 1/8 inch increments. As an example, a PAR 16 divided by 8 equals 2 inches in diameter. A PAR 30 divided by 8 equals 3.75 inches in diameter, and so on. LENGTH OF A LAMP: Some lamps come in more than one length. Please consult our list for exact lengths. CLOSING COMMENTS: We hope that this will help you out in cutting down on the confusion about halogen lamps. We've covered the main areas of concern that our customers encounter, and, yes, there's more. Feel free to contact us for any questions, comments or clarification. We look forward to doing business with you!