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Article #7767Re: K-Ar laser lifespan
From: Michael Cammer
Date: Thu, 11 May 1995 00:00
Date: Thu, 11 May 1995 00:00
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These lasers definitely do not have the advertised lifespan. But, fortunately, we have always gotten more than 50 hours of red line from each. Our laser gets used for at least a few hours every weekday (and sometimes in the evenings or weekends) and we have needed a replacement laser every 9-12 months; at one point we got a succession of bad lasers that needed rapid replacement. Often the red line does disappear, but adjusting the back mirrors can usually bring it back. This used to not be a problem, but now with Cy5 becoming a very popular stain, we need a good steady red line. Running the laser at low power, even if this worked for rhodamine (which it doesn't really), is not an option. Also, before BioRad replaced the AC power supply with a DC, this was not an option since the horizontal banding was worse at low than at high power. Over the years this discussion pops up every once in a while and the same answers seem to be posted-- yes, this is a repetitive message. Yes, we have run through a number of lasers and we could post anecdotes about the good ones (we have one now, but read below), but overall, although these lasers work well when they are working, they don't work for very long-- not 2000 hours! Or weird things happen. Such as: a few weeks ago the red line spontaneously disappeared; tweaking the mirrors brought it back. Or, suddenly, without any warning, a few weeks ago the laser power dropped. We turned the laser off and when we turned it back on it was working fine and has been since. Why doesn't BioRad install the low/high computer controlled switch? On Wed, 10 May 1995, Colin Macqueen wrote: > We are now re-installing Bio-Rad Australia's "replacement" K-Ar laser for I > think the sixth time in just under three years as our original laser is > still problematical. Invariably it is the red line which fails within > about 50 hours of use. I have put out a goodly number of distress calls and > am only now realising the extent to which there has been a worldwide > problem. Bio-Rad have always acknowledged the extent of MY problem and been > very supportive but for commercial reasons or from genuine lack of > knowledge have not informed me of just how extensive the problem seems to > be. > I routinely have a multi-meter attached to the laser head and during the > course of a days work jot down the laser power and anode current values a > number of times. We have the "cut-out" option on our laser head so will > report if or if not a significant difference in life-time comes about. It > wouldn't take much for there to be an improvement as far as I'm concerned!
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 114d69,182d1fb89456df96 X-Google-Attributes: gid114d69,public From: Michael Cammer <cammer@AECOM.YU.EDU> Subject: Re: K-Ar laser lifespan Date: 1995/05/11 Message-ID: <Pine.3.07.9505110920.A21846-c100000@alsys1> X-Deja-AN: 102513006 sender: Confocal Microscopy List <CONFOCAL@UBVM.CC.BUFFALO.EDU> comments: Gated by NETNEWS@AUVM.AMERICAN.EDU content-type: TEXT/PLAIN; charset=US-ASCII mime-version: 1.0 newsgroups: bit.listserv.confocal