Waters 2487 Self Diagnostic

[gbalock]

We have encountered a problem in which the detector fails our wavelength calibration (phenanthrene & anthracene in the cell), but when the internal wavelength check on the instrument is done and there are no error messages. I guess that my question is, what is the value of the self check?

[DR]

I can't remember - are 2487s dual lamp detectors? If so, the UV lamp may have gone bad. As HOlmium oxide filters are quite useful in checking wavelengths in the visible end of the spectrum, they are not so good at checking the UV end... hence the passing of internal checks.

[danko]

DR – one lamp only.

Gbalock – I guess it’s a question of acceptance criteria. Try to compare the tolerance allowed in the factory settings to your procedure’s limits.
The need for wavelength accuracy can vary a bit, depending on the intended application, but as a rule of thumb 2-3 nm should be acceptable.

Best Regards