On Mon, 1 Jul 1996 08:39:29 +0100, Elaine Levy wrote:
 
>Has anyone else noticed an increased frequency of mercury bulb explosions.
>Having been told it never happens....
 
We have not had this happen for a long time, but about 6 or 7 years ago
there was a world wide surge in lamps exploding well inside their due time.
We had thought it was a local problem at first, due to the extreme
fluctuations in mains power we used to get, and put all our transformers on
a regulated power supply. It didn't work. We put cooling fans on our lamp
houses. We couldn't get that right  to avoid running them so cool that no
useful light came out. In the end we corresponded with the manufacturers
(Osram) and got all the standard advice (regular power, leave on for long
times, hands off the glass etc) but no real solutions...
 
In a chance discussion at a meeting in Europe it
turned out that many labs were  having the same problem with 50W burners.
The story that was out was that there was a particular person who had
worked making the bulbs (or supervising their manufacture) for years and
years and that he had retired....and then it took some time for the
standard to come up to scratch again....
 
I don't know if this story is true or not (it would be good to have it
confirmed one way or the other) but if it is, then perhaps the staff or
methods have changed again...
 
Ushio in Japan makes good bulbs (they come supplied with Olympus
microscopes) although I think they are more expensive than the Osram ones.
 
This probably hasn't been much assistance, but I agree it would certainly
help to know if this is a widespread problem looming up again...
 
IAN
Professor Ian Gibbins
Department of Anatomy and Histology
Flinders University of South Australia
GPO Box 2100 Adelaide 5001
AUSTRALIA
Phone:  +61-8-2045271
FAX:    +61-8-2770085
e-mail:  [log in to unmask]