sbtan

Ufortunatly buying a meter will not tell you specifically when the lamps need to be changed. You would have had to have them metered when they were new as something to compare the decrease in output too, as stated earlier your bed and the conditions that it operates in will effect the output. So if you buy a meter and the velocity's read 11 and the Velocity Plus' read 10 what will that mean to you.

1TANS

HAVE 48 FR73 SPECTRALARIUM VHO/R+ FACTORY BOXED FROM PURETAN
CALL 817-312-2200 Jim

solarmeter

If you had a couple new lamps of the same kind left over from when they were last changed, you can put them in and compare meter readings to the old ones.

Rule of thumb is never let them fall more than 30% before changing them. Most of the drop off happens in the first 100 hours... then it levels out toward maximum life - which varies all over the map.

Some lamps last 300, 500, 700+ hours before decaying 30%. Hypothetical example for a set reading 40.0 mW/cm² new after ~10 hour break in:

10 hrs............ 40.0
50 hrs............ 37.2
100 hrs........... 34.5
200 hrs........... 33.7
300 hrs........... 32.6
400 hrs........... 31.2
500 hrs........... 29.1
574 hrs........... 28.0 (down 30% to 70% of original new 40.0)

ED ST

It doesn't matter if your lamps have 10,000 hours on them and are 100% degraded. If they still tan your customers, and your customers keep coming back for more, keep using them. Conversely, if your lamps, whatever they are, only have 100 hours on them, and they are only 10% degraded, but all of your customers are complaining that the lamps aren't tanning them, you had better changer them ASAP, or you will be out of business much sooner than later.

solarmeter

Now Ed... that's just plain "stupied" and you know it. You're just trying to get my "goat" enough to time me out(again).

Ed is a salesman type and doesn't appreciate science (or meters) like his cohort John does. Ed is kinda like the S. Underhill of the lamp distributor world... plenty of hot air.

The first part of what he says is impossible.... 100% degraded will tan no one.

The second part of what he says could only be true if the same customers were also complaining at zero (new) hours.... meaning the choice of lamps were wrong for the bed exposure schedule from day one.

ED ST

"Stupied"? Is that the same as being stupid and getting a pie in the face, all at the same time?

solarmeter

I don't know. Ask Mitzi. She invented the term down in them thar hills.

mr belvedere

I think it's stupide. Or is it stoopit? I'm too dumb to know the diff. But SM, tell me more about this goat of yours. Does it give good head butts? I understand that many goats, especially those named Billy, love to give head butts. What is your goat's name, BTW? And why does Ed want to get it so bad? Perhaps something to balance his butt head? You guys. ~sheesh~

nutanner

That's why he's the King...he cracks me up...anyway I've tested lamps several ways...I have a bed that hasn't had a lamp change in almost 2 years, and it still reads stronger than any other 20 min bed I have on the meter...don't know why but if it aint broke I aint gonna fix it...other beds I change at 500 hours in a rotation...top lamps to bottom and bottom trashed obviously at 1000 hrs...works very well...less back burning and striping of customers.

olydave

http://www.tantalk.com/viewtopic.php?topic=2346445&forum=14
This is a great post for instructions on how to meter because...if your asking the wrong questions the answers really don't matter. By the way King, it is speeled stewpid.