measuring flourescent tubes

[steveo3002]

ive got a 5ft flouro tube tube , i see the shops have 1500 . 1514 , 1520 which all might almost match up depending on where its measured from

is it the glass or the end of the pins you measure to ?

 

[voipio]

Normally to the ends of the pins.

 

[roofman]

ive got a 5ft flouro tube tube , i see the shops have 1500 . 1514 , 1520 which all might almost match up depending on where its measured from

is it the glass or the end of the pins you measure to ?

Measure the light fitting instead and see what goes in the hole with ease

 

[eSCHEn]

Umm, measure the old one?

 

[brightspark]

Umm, measure the old one?

or take it as a sample

 

[dobbslc]

Buy one from the shop that sells them in feet not millimetres!
You'll probably find those above are all the same tube length.


 

[brightspark]

best laugh I had on a job was the builder in front of his blokes asked me how long a 5 foot fitting was .err 5 foot innit he was making a cabinet for it in a window and wanted the clearance size but we all took the pee

 

[123hotchef]

off topic a wee bit why do the florescent lamps not want to work when its cold in the shop?

 

[steveo3002]

Buy one from the shop that sells them in feet not millimetres!
You'll probably find those above are all the same tube length.


well its kinda what im getting at...best i can tell mines 1514mm but are they all interchangable for the sake of a few mm , no good asking in th diy stores etc as they wont know

seems 1514 is harder to find where 1520 and 1500 are more common

 

[dobbslc]

That's 5 foot innit?

 

[brightspark]

off topic a wee bit why do the florescent lamps not want to work when its cold in the shop?

u normaly only get that with the old 8 foot fittings with 125wtubes the 8 foot 100 watt bulbs are a bit less problematic

 

[123hotchef]

mine are a pita

 

[dobbslc]

They're often slow when cold but should start. I think the cold slows down the electrons or something and makes the arc harder to start.

Probably need new ones and decent starters.

 

[brightspark]

mine are a pita

get them replaced to 6 foot

 

[sparkysy]

@123hotchef
High frequency ballast in the newer fittings will strike better than switch start in the cold! I agree with brightspark!
Sy

 

[Turbo]

off topic a wee bit why do the florescent lamps not want to work when its cold in the shop?

If yours are the type with the small round starter that you can remove I would suggest replacing the starters with an electronic starter. This is the type of thing I mean.
https://www.energybulbs.co.uk/produ...&network=pla&gclid=CNr-8tKY3tACFUG7GwodprkFHQ
They work a lot better in cold weather & extend the life of the tubes. On that subject, when's the last time you replaced the tubes as a tube that's slow to start can be a sign they're near done. The other sign is the tube going black at the ends.

 

[123hotchef]

my light fittings are probably 20 years old at least yep with the old style starters too, maybe it is time to replace the whole fitting with some nice LED ones, they just replaced the ones in the stables to leds I thought they looked rubbish but the light output is great.

 

[GW8IZR]

best laugh I had on a job was the builder in front of his blokes asked me how long a 5 foot fitting was .err 5 foot innit

:-)

A colleague and self were sat in an airport departure lounge, we were chatting about modern insulating membranes, I showed him a sample which was like aluminium foil backed bubble wrap which was claimed to be better than 300mm of fibreglass, after a long silent period of study he announced 'blimey thats nearly a foot' quite few passengers that were covertly following the story (as you do) burst out laughing.

I needed some stainless metric tubing and aluminium sections for a project, I rang a firm thats name contains the words ..stainless metric supplies... and asked them what they kept in stock, they had some 25.54mm etc ...........

off topic a wee bit why do the florescent lamps not want to work when its cold in the shop?

Sooo.. to work the cathode of the lamp needs to be hot to emit electrons, the heat is created by the electrical power. Those electrons bump into the gas in the tube and cause an effect called impact ionisation and without those impacts its just a dull glowing tube.

The running voltage is reduced by the balast coil but for the initial strike to occur the required voltage is higher so the 'starter' switches the balast in series with the filaments. The electronic starters shape the wave better than the old bimetalic ones improving the start. Once the tube is hot the emission of the cathode is sufficient to not need the starters pre heat. As the tube ages the cathode emission reduces making the starting process harder. The temperature of the tube directly affects the gas pressure and in cold weather its lower also making the strike harder to begin. The reason they start and stop and flicker is because the running condition isn't keeping the cathode hot enough for sufficient emission. Sometimes the old bimetalic starters leak their inert gas a bit and then they switch on and off randomly, this changes the configuration of the balast which cocks the whole thing up, you can test this by waiting till the tube fires then whip the starter out and the light should stay running. Anyway thats a further digression :-)

Damp on the outside of the tube also affects the strike which you can test by wiping them with a dry cloth and see if it changes, usually when they are slow to start in cold / damp conditions they are close to their end anyway. I used to warm the one above my workbench with a propane torch until the inevitable happened :-)

 

[Shox Dr]

my light fittings are probably 20 years old at least yep with the old style starters too, maybe it is time to replace the whole fitting with some nice LED ones, they just replaced the ones in the stables to leds I thought they looked rubbish but the light output is great.

Tubes loose a massive amount of light output, down to around 40% in under a yr with constant use. (8hr/day)

 

[123hotchef]

get and LED one much brighter