I was wondering if anyone has date code keys for sylvania or GE fluoro tubes or westy lifeguards. If anyone does please let me know. Thanks

I was wondering if anyone has date code keys for sylvania or GE fluoro tubes or westy lifeguards. If anyone does please let me know. Thanks

yes. I have Sylvania it is on the files on the Facebook FLF

Be careful. Don't spread the word. Date codes are usually confidential information.

Be careful. Don't spread the word. Date codes are usually confidential information.

Confidential could be only the original documents from those companies. If someone else decipher the system and publishes it (e.g. in a form of table or so), they have no legal means to do anything with it.
But in that case the legal ownership to the tables belong to that guy who has made that table and he has all the rights to decide, how or where to spread it or not.

Be careful. Don't spread the word. Date codes are usually confidential information.

Medved agree 100%. I worked out thirty years ago how to read Sylvania dates from English lamps. The dot subtraction method is all but consigned to history except on a handful of tubes they import to Europe from China. The document I have written is my own, explained in my own  words. The first lamps I had dated were read out to me over the phone at the Shipley factory in the north of England. This plant does not even exist. And as for the current US lamp code, it is copied directly from a well known Osram European weekly code, that was explained in detail to me by Osram GEC back in 1994. Again, the operation has ceased, there is no 'company' to threaten an enthusiast for knowing (or showing) how old a lamp or tube is. Especially that Osram's BARI factory in Italy print the ACTUAL date next to the date code!!!  And as for making all this open to the wider public, they are frankly not interested in lamp dating to the extent that we are, so it would be a waste of time!

The "encryption" of the date codes was primarily intended not for secrecy, but for cost and look (the letter/numbers date codes would spoil the artistic qualities of the early etches, with the missing dots and dashes you even do not regiister anything is there).
Over the years the amount of information that has to be printed on the etch grew, but at that time the system was already set. Plus the dots and dashes are cheaper to maintain on the machinery than the alphabet set.

Now it comes only with modern factories, where the stamping process does not use anymore the complete ornamental stamps, but a computerized ink jet printing for the etches. With that it cost nothing extra (mainly in the equipment maintenance) to use the full alphabet, so they switch to plain alphanumeric codes. Other part of the motivation was the older dots-and-dashes (or whatever it looked with each company) cycle was already repeating many times, causing customer support confusions, mainly with the long life lamps. So once the machinery was upgraded, practically all makers are switching to plain text now.

yes. I have Sylvania it is on the files on the Facebook FLF

What is Facebook FLF?

What is Facebook FLF?

Flourescent lighting forum

Is that a forum that's open to the public? I searched Facebook and couldn't find it.

@ nogden and xelareverse it is a closed group. Pm me your Facebook profile links a I I can add you. Alternatively if you are on the Facebook Lighting Gallery Members group, drop me a line, I'm Lee Newton. Cheers!