Do HIDs lose brightness over time?
02-13-2014, 06:00 PM
#21
AudiWorld Super User
Very interesting mithrilG60 because metal halide lamps use salts in the same manor for a more pure white color vs mercury vapor that don't use salts, but I do have to state that several times before I changed my aging 9yr old HID lamps I did notice more of a pink during the start-up instead of the yellow like my 1yr old ones.
02-13-2014, 07:13 PM
#22
AudiWorld Member
Yup, colour shift to violets and pinks are very characteristic of HIDs that are at end of life. That colour shift will also show in normal use and not just start up. The bulbs light colour is determined by the chemical composition of the salts in the capsule, that composition eventually begins to break down after a certain number of cycles. The average functional life of a HID capsule is about 2000 hrs, it may continue to work after that point but it's life output will be dramatically reduced.
02-14-2014, 01:59 AM
#23
Audiworld Senior Member
Thread Starter
Very interesting mithrilG60 because metal halide lamps use salts in the same manor for a more pure white color vs mercury vapor that don't use salts, but I do have to state that several times before I changed my aging 9yr old HID lamps I did notice more of a pink during the start-up instead of the yellow like my 1yr old ones.
02-17-2014, 05:52 AM
#24
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HID, tungsten, HIR and Halogen bulbs start to loose output from the day they are put into use. I recommend changing out both low beam bulbs every two to three years if you notice any reduction in output.
With HID's the salts start to accumulate and cloud the center of the tube.
With HID's the salts start to accumulate and cloud the center of the tube.
02-17-2014, 01:03 PM
#25
Audiworld Senior Member
Thread Starter
HID, tungsten, HIR and Halogen bulbs start to loose output from the day they are put into use. I recommend changing out both low beam bulbs every two to three years if you notice any reduction in output.
With HID's the salts start to accumulate and cloud the center of the tube.
With HID's the salts start to accumulate and cloud the center of the tube.
02-17-2014, 02:03 PM
#26
AudiWorld Super User
Does your chewing gum lose its flavor on the bedpost overnight?
02-17-2014, 02:03 PM
#27
AudiWorld Super User
Yep.
02-17-2014, 02:32 PM
#29
AudiWorld Super User
Are we confusing the start up colors?
Pink=beginning of the end
Yellow=normal shade before white
If your has HID lamps then yellow...... well you know.
Unless they are 4+ years in heavy service use then a fraction of overall brightness will be noticed.
Pink=beginning of the end
Yellow=normal shade before white
If your has HID lamps then yellow...... well you know.
Unless they are 4+ years in heavy service use then a fraction of overall brightness will be noticed.
02-17-2014, 02:58 PM
#30
AudiWorld Member
AudiWorld
Exactly. A yellow colour band in operation is completely normal for stock lights. As I mentioned earlier, it's from the diffraction of light bending on the edge of the cutoff shield. The colour of that band is dictated by a bunch of factors including distance of the shield from the back of the projector bowl, shield shape/curvature and the lens type. However the colour has nothing to do with the health or age of the bulb.
Similarly the clouding of the capsule with salts indicates nothing more than the capsule has been used. HIDs work by using electric current to vapourize salts in an enclosed capsule, super heating them to plasma. The plasma emits light at a specific wavelength (ie. colour temp) defined by the composition of the salt mixture. When the current is turned off the plasma cools and the salts recrystalize. The cloudiness is just finely crystallized salt which will again turn to plasma the next time the bulb is energized.
Similarly the clouding of the capsule with salts indicates nothing more than the capsule has been used. HIDs work by using electric current to vapourize salts in an enclosed capsule, super heating them to plasma. The plasma emits light at a specific wavelength (ie. colour temp) defined by the composition of the salt mixture. When the current is turned off the plasma cools and the salts recrystalize. The cloudiness is just finely crystallized salt which will again turn to plasma the next time the bulb is energized.