By Lee Oliver
Dear Infophile Guy:
Why, when you turn them on, do fluorescent lights flicker spasmodically?
Name Withheld ‘Cause the Infoguy, Like, Lost the Original Question.
The crazed flickering and sputtering syndrome is, sadly, found only in the older or cheaper “preheat” and “rapid-start” versions of the fluorescent lamp. The state of the art “instant-start” seems to be above acting spasmodic. Too bad really, since the only endearing quality of these heartless, soulless bastard lamps is their super-human struggle to light up.
At any rate, Name Withheld had a query, and I better get going. It seems to me that this same question was thoroughly dealt with on “The Secret Life of Light bulbs,” which recently aired on one of those Ted-Rogers-forced-it-down-my-fuckin’-throat cable channels. (It might have been on Discovery, or TLC, or the Light bulb Network or whatever—as long as they keep switching which network appears on which channel, I’ll never figure out what the hell I’m watching.)
Still, I’d be pleased to answer the question, if only to give me an excuse to babble on in a manner suggesting I actually care about the inner-workings of light bulbs.
To let you in on the secret of the spasmodic flickering, it is going to be necessary to tell you what is inside these wacky fluorescent lamps. These glass tubes contain, at low pressure, a small amount of mercury and some other chemically inactive gas—usually argon. The inside of the glass is coated with phosphors. (Since I know you’re gonna ask, phosphors are chemicals that emit light when excited by radiation. Humans, on the other hand, when excited by radiation tend to emit gooey, oozing wounds where their flesh used to be; but that is another column). At each end of the tube is an electrode made of a tungsten coil coated with chemicals called “rare earth oxides.” Outside of the tube, hidden in the light fixture, is a ballast connected to the electrodes, which provides the voltage to start the lamp and then regulates the flow of current.
Now that you’ve got the parts list down, I can now tell you how it works. When a funky preheat or rapid-start lamp is turned on, electricity flows through the tungsten wire. As the wire heats up, the oxide coating gives off electrons. Some of these electrons strike the argon gas. The gas, in turn, becomes ionized. Once ionized, the argon gas can conduct electricity, which it does from electrode to electrode, forming an arc. This, my missing friend, is the cause of the sputtering, spasmodic dance that precedes the light. The newer, totally soulless instant-start lamps kick in with such a powerful jolt of electricity that the arc forms instantly. snoooozzzzzzze.
Perhaps it is my obvious disdain for these bastard tubes that has prevented me from conducting the usually thorough research that has become the hallmark of this column, but I’m truly stuck for some decent fluorescent lamp urban lore or tacky trivia. Honestly, the only fun thing about fluorescent tubes, aside from their heroic efforts to—zzssttsds…craccccklke…plaaukss—light-up, is that they blow up real good when you toss them off the sixth level of a parking garage. But I cannot recommend that, even in the name of experimental science, as those who secure tend to frown upon such activities.
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