Chromatography Forum

I've posted about this before ( viewtopic.php?f=1&t=18568 ) but was never able to find a resolution. Long story short, my Waters 486 failed the initial wavelength calibration due to low lamp energy. I replaced the lamp, and got a reference energy value of 54 when it should have been closer to 100. I believe that either I got an old lamp, or possibly that a mirror or window in the light path is solarized (turning yellow). Does anyone have any experience with this type of situation? Is it possible to replace the solarized part (be it window, mirror, or whatever)? If so, where would I find such a part? Also, I noticed that before this occurred I was able to use the detector by just never turning it off, and only turning off the lamp, so that it never went through the startup diagnostics. The noise level was perfectly fine for my applications. Is there a way to tell the detector to bypass the diagnostic at startup, or to ignore the fact that it failed?

My best success with dealing with this error is to have a flow going through your cell and then try to power-up. It may take a few times but it usually comes up. Have you tried to clean your cell? Have you placed fresh solvent in your reference cell?

It has been a bit of time since I have had one of these detectors but it was not too hard to disassemble. I'm not sure of part numbers nor parts available. I know you can buy a lamp kit still from Waters (easily found on their website) and it comes with the lamp, a battery a lens and dust filters.

Thanks for the reply. Power cycling didn't help. Each time I got the same value for the reference energy (13). I was finally able to fix the problem by back-flushing the reference cell with methanol. I got the reference energy to increase from 13 to 27 (don't know the units). Apparently that was enough for it to pass the wavelength calibration.

Hi ScottHorn,
At first adjust the lamp position to maximize the energy. Check the lens and optics window. Generaly the lens must be replaced with the lamp, because it is close to the lamp and quickly solarized. Try to clean it with ethanol and lens tissue. Flush the cell with HNO3.