What is the typical lifespan of the bulb in a Beseler 23CII condenser head? I got about 5 1/2 weeks out of my last one, using the enlarger two or three times a week for one to two hours at a time. Is this typical?

Thanks,

Peter Schauss

-- Peter Schauss (schauss@worldnet.att.net), December 24, 2001

Answers

I wouldn't think so. We have 5 23c's in our lab, they are used 6 days a week for many hours at a time, We don't average one bulb a year for all. I did have a Omega B22 that had a bulb problem, had to change it in less than a week, checked the wiring and replaced the bulb twice and that seemed to do the trick. I checked with my dealer about any other problems they might have had with their last shipment, however, they had no other problems. I would check the wiring. We have 12 enlargers with serious use, the biggest bulb replacement problems are from the dichroc heads. I don't know if this is any help are not, but i would have to say in my many years of work this is not a normal problem.

-- Ann C lancy (clancya@mediaone.net), December 24, 2001.

No, it donesn't seem typical at all. Abnormally short, in fact. I don't know what the averages are, but you should make sure you have the right bulb for your line voltage.

If you have access to a line voltage meter, see what your line voltage is running. Incandescent bulb live reduces exponentially (or moreso) as voltage is increased linearly.

-- Charlie Strack (charlie_strack@sti.com), December 24, 2001.

I get years out of those bulbs. Good idea to check your line voltage. The reduction in life with increasing voltage is almost unbelievable. The formula is (design voltage/actual voltage) to the twelveth power! The usual design voltage for the US is 120, so a bulb running at 125 will only last about 0.61 of what it should. They also get unhappy if ventilation slots are plugged up.

-- Conrad Hoffman (choffman@rpa.net), December 25, 2001.

I have no data on bulb life, but I think you shouldn't be able to remember exactly when you last replaced the bulb. That is, they should last a lot longer than 5.5 weeks. However, I've had the 111A bulbs last a very long time, only to be replaced by another one that popped after just a few weeks. If your voltage is right, don't fret if a bulb pops too soon every couple of years. Just be sure to have a spare when it does go, or you'll really be pissed if it happens to be late at night.

-- Keith Nichols (knichols1@mindspring.com), December 25, 2001.

If you moved your enlarger abruptly when its lamp was hot, that could explain its short lifespan. All lamps (and especially the high wattage ones) dislike recieving schocks when they are lit (and hot)...

-- George Papantoniou (papanton@hol.gr), December 30, 2001.

When handling high intensity bulbs (like those for enlargers), make sure that you don't touch them with bare hands. The oil and other residue on your hand can shorten bulb life significantly.

-- Michael Feldman (mfeldman@qwest.net), December 30, 2001.