Fluoresecent tube lengths

[JohnW2]

Being a very curious soul, something has just occurred to me ...

I have several fluorescent tube fittings around my house, mainly "4ft" and "5ft" ones. Some are very old, hence probably there since 'Imperial' days.

Although some of the tubes I buy are still called "4ft" and "5ft", many are now sold as "1200mm" and "1500mm", but all fit OK. Measuring them, they are, indeed, exactly 1200 or 1500mm long, excluding the pins.

So where did the original "4ft" (1219.2mm) and "5ft" (1524mm) descriptions come from? Did those dimensions include the pins and, if so, is it pure co-incidence that the corresponding tube-only dimensions (excluding pins) just happened to be very nice 'round' figures in metric??

Kind Regards, John

 

[EFLImpudence]

I don't know the answer.

How long are your 4ft and 5ft ones?

 

[Iggifer]

I don't know the answer.

How long are your 4ft and 5ft ones?

4ft and 5ft I suspect

It must just be excluding and including pins if they're the same overall length. Flourescent tubes are about the only thing I use imperial for. I got asked to 1st fix some wall lights at 6ft the other day, had to go find a tape measure that had feet and inches on it

 

[JohnW2]

How long are your 4ft and 5ft ones?

Exactly the same as the 1200mm and 1500mm ones - i.e. exactly 1200mm & 1500mm excluding pins, but almost exactly 4ft and 5ft if one includes the pins!

Kind Regards, John

 

[EFLImpudence]

Ah well. There you go.

 

[JohnW2]

It must just be excluding and including pins if they're the same overall length.

Indeed - that's the only really credible explanation.

However, it seems an amazing co-incidence (almost 'too good to be true') that tubes (and fittings) originally designed to have overall (including pins) lengths of 4ft and 5ft turned out to have tube lengths (excluding pins) of exactly 1200mm and 1500mm!

Kind Regards, John

 

[EFLImpudence]

Or maybe no one measured the metric length.

They still make them on the same machine and just multiplied by 30 - near enough - to 'go metric'.

After all they're the same height stood on end.

 

[JohnW2]

Or maybe no one measured the metric length. They still make them on the same machine and just multiplied by 30 - near enough - to 'go metric'.

They clearly must be exactly the same dimensions as they always were ('still made on the same machine'), since most fittings would be intolerant of even small variations in dimensions. I doubt that they would 'dare' label them with metric dimensions which were systematically only approximate (always ~19 or ~24 mm 'wrong'), so I suspect their argument would be that they changed from using overall length to tube-only' length when they changed to metric. The packaging doesn't indicate what the "1500mm" (or "5ft") refers to.
(apropos a different thread, that's a preposition at end of sentence, for informality - and, FYI, my fingers just typed "there argument", until I noticed and corrected it!)

Kind Regards, John

 

[EFLImpudence]

The packaging doesn't indicate what the "1500mm" (or "5ft") refers to.

That's interesting.
"The packaging doesn't indicate to what the "1500mm" (or "5ft") refers" isn't right either.
It would indicate you need a different sentence.
"The packaging doesn't indicate what the "1500mm" (or "5ft") specifies." ???

and, FYI, my fingers just typed "there argument", until I noticed and corrected it!)

It happens.

 

[JohnW2]

"The packaging doesn't indicate to what the "1500mm" (or "5ft") refers" isn't right either.

What's wrong with that (other than that it sounds formal/awkward/'posh' - which is why I don't like using it)? Would you perhaps be happier if I changed "refers" to "relates"??

Kind Regards, John

 

[JohnW2]

Just to add to the confusion, as well as "1200mm" and 1500mm" ones, Sylvania also offer 1199mm (47.20") and 1449 (57.04") ones - not to mention 590mm (23.23"), 1149mm (45.24") and 1764mm (69.45"). What's that all about, given than none of those dimensions are remotely 'round' in either Imperial or metric?!!

Kind Regards, John

 

[EFLImpudence]

What's wrong with that (other than that it sounds formal/awkward/'posh' - which is why I don't like using it)?

I don't think it sounds formal or posh; just awkward but if you think it is alright then that would be correct.

Would you perhaps be happier if I changed "refers" to "relates"??

I don't think that makes any difference. What's wrong with 'specifies' or 'indicates' again (perhaps change the first 'indicate')?

 

[EFLImpudence]

No thoughts on the really odd measurements.

 

[JohnW2]

Would you perhaps be happier if I changed "refers" to "relates"??

I don't think that makes any difference. What's wrong with 'specifies' or 'indicates' again (perhaps change the first 'indicate')?

Nothing - but what made you say that the version with 'refers' was 'not right'?

Kind Regards, John

 

[Echo the husky]

Perhaps Sylvania were just measuring really accurately! Talking of odd sizes, in one of my 1930s magazines they briefly mention 9' and 12' fluorescent tubes! Has anyone come across tubes of these sizes?