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How to measure a fluorescent light bulb? Here's how you do it.

When people call to identify a fluorescent light bulb, only some of them know how to actually measure it. So we'd like to correct that with some simple information that will help you accurately determine which light bulb you have. So how do you measure a fluorescent light tube? Simply lay out the tape measure to get a length making sure that you're measuring from tip to tip. A lot of people think that you measure just the glass portion and that would be incorrect. There have been many calls where people have talked to me and tried to correct me on this because they don't want to believe what I'm telling them. Believe me when I say it's measured from tip to tip otherwise you won't get a correct measurement and you'll never find the bulb you're looking for. Often I'll get somebody saying that they have a 47 inch fluorescent bulb and there is no such thing. And they'll say "it says 47 inches", but what they don't know is that our industry measures it from tip to tip, so it's actually 48 inches. Are you getting the idea now? There's only so many ways I can say it. It will alleviate a lot of the frustration people feel by calling many different lighting companies and trying to determine why nobody has this oddball size fluorescent light bulb that nobody has. The length of the fluorescent tube can tell us a lot about which one it is and most of the time we can identify it right away because of the length. It's not the only determining factor, there are things like phosphor color, wattage and diameter to make a full identification of what you have. But the length is one of those important things that we have to get right. On occasion, I have talked to people that have a very oddball size, something that was maybe imported and was never for general release here in the United States. That does happen but not very often. If you find yourself in a situation like that, you have my sympathy. There were a lot of light fixtures that were imported by these big box stores based solely on price. But what they didn't consider was that the bulb used in that light fixture was something that neither they nor anyone else could get. So getting back to the point, a fluorescent tube is measured from tip to tip.
I hope this helps, let us know if you have further questions.

John Bolduan

Here's some fluorescent light bulbs that people commonly measure:

Displaying products 1 - 3 of 3 results
F17T8 Fluorescent Light Bulbs
F17T8 fluorescent light bulbs are a 2 foot energy saving lamp.
Price Each: Starting at $6.36
F17T8 Fluorescent Light Bulbs
F32T8 Colored Fluorescent Light Bulbs
F32T8 fluorescent colored light bulbs in red, green, blue, pink and more.
Price Each: Starting at $13.98
F32T8 Colored Fluorescent Light Bulbs
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