We recently wrote about incandescent bulb part numbers, discussing the difficulties that come with translating a native language into a secondary language.
Some people say that there are certain languages that are easier to translate than others, because of how they are structured.
In the language of part numbers, it is safe to say that fluorescent part numbers are much more difficult to translate and understand than incandescent. This is largely due to the fact that each manufacturer speaks a different dialect of the fluorescent language, causing us –– the eavesdroppers trying to make sense of all the seeming gibberish –– to have to learn their various colloquialisms. This is why knowing each manufacturer's part number dialect is important. If we only knew one language we may give up looking for a bulb, though a near-identical bulb almost always exists, just in another part number form (or language, or dialect).
General linear fluorescent part number structure
Here is a pretty common example part number: F32T8/TL741/ALTO
Let's break it up to show you what each section corresponds to.
F32T8 – The first section in the part number tells us the shape and wattage of the lamp. There can be manufacturer nuances in this section.
TL741 – The second section in the part number tells us the CRI series and Kelvin temperature of the tube. There can be manufacturer nuances in this section.
ALTO – Okay, here's where those manufacturer colloquialisms really come in. In the industry, we call this final section the "description." And there can be multiple descriptions or none at all. But these descriptions are different from manufacturer to manufacturer.
Shape and wattage in fluorescent part numbers
Linear fluorescent lamps typically include a “T” in the shape abbreviation with a number following it. This “T” stands for tube and the number that follows is the diameter of the tube, which is divided into 8 to translate into inches.
Here's a helpful diagram that
With fluorescent tubes we see different manufacturers abbreviating shapes differently.
Here is a list of common abbreviations:
The wattage tells us two things. The amount of electricity the tube is consuming and the length of the tube. The diameter simply tells us how thick the tube is, but we need the wattage to tell us how long it is.
CRI and color temperature in fluorescent part numbers
Each major manufacturer seems to designate their CRI series differently.
Here's a breakdown:
The CRI series is partnered with a number that represents the Kelvin temperature, or color temperature, of the tube.
For example, if it's a T12 700 series 4100 Kelvin temperature tube from Sylvania, the designation would read D41. You just drop the two 0s off the temperature number. And if you were to cross that to the Philips version, you would change it to SPEC41.
To learn more about CRI and how it impacts your lighting, check out our Guide to CRI and CCT.
Descriptions in fluorescent part numbers
The description at the end of the part number gives us extra information about the tube. For example, if it’s energy efficient, low mercury, the ballast starting method, etc.
Here is a list of common descriptions you’ll see at the end of part numbers:
RS – Rapid Start
HO – High Output
VHO – Very High Output
ECO – Low Mercury (Sylvania & GE)
ALTO – Low Mercury (Philips)
SS – Super Saver (Sylvania)
EW – Econo Watt (Philips)
WM – Watt Miser (GE)
ADV – Energy Advantage (Philips)
XPS – Extended Performance (Sylvania)
If this sounded like a bunch of gibberish to you, that’s okay. We take the time to really understand the complexities of part numbers in order to make your job simpler and easier. There’s no need for you to check the best price point of every single possible part number for a certain bulb. Let us do that.