Chromatography Forum

I just finished changing the deuterium lamp in a Waters 486, and I can't find an answer to this question in the manual. When I monitor the reference energy to determine the optimum position of the lamp, what are the units on this number? What is the range? I assume a dead lamp gives 0, but how do I know I didn't get a bad lamp? I have no trouble finding the maximum value, but I don't know what type of number to expect.

Below 50 and and the lamp won't calibrate, a new lamp should read 100. I don't recall the units.

Are you sure of that? The maximum I got out of this "new" lamp was 54. I hope I didn't get a lamp that had been sitting on the shelf for a few years.

Could be that your optics are a little solarised and thus the low value.

Could be that your optics are a little solarised and thus the low value.

Agree! I assume the detector is rather old? We have a lot of 8-10 your old Waters Alliance systems, and I think that we have changed the mirrors in most them by now. If the mirrors are bad, you will never get a good lamp energy.

Some of them had problems with the windows going yellow, maybe that was the 996 PDA but I can't remember, it's been a while!

No idea as to its age, I bought it used. How difficult is changing out a mirror? Are there any other optical components I should replace while I'm in there? Finally, where would I find replacement mirrors etc?

Yes-I am sure of the numbers, as it came directly from Waters. But I have a service contract so I can't help with troubleshooting.