Water Acquity PDA calibration issue

[tsoukalas]

Dear users,



I am facing an issue with a Waters Acquity PDA detector.

This problem makes me completely crazy, and i would like to have some help or an explanation. That is why i post on this forum.



We are unable to calibrate the PDA. The error message is wavelength verification failure at startup and λ1 is out of range during Erbium calibration (199.350). λ512 is ok at 801.629. I am in service mode

I tried many differents things :

- flush the flow cell, clean it with appropriate solvent, clean it again with dilute formic acid, clean it again with dilute nitric acid. same issue

- Then i replaced the cell : same issue

- I replaced the D2 lamp with a new one : same issue



My feeling is that the issue could be solved in the mercury calibration panel, but i don't know the process for repair.



If anyone are facing the same issue and know how to resolve it, i highly appreciate your help.



thank you a lot,



Pierre

[Hollow]

Dear users,

We are unable to calibrate the PDA. The error message is wavelength verification failure at startup and λ1 is out of range during Erbium calibration (199.350). λ512 is ok at 801.629. I am in service mode
Pierre

Have you searched the Waters knowledge base?

Maybe this corresponds to your issue:
https://support.waters.com/KB_Inst/Chro ... on_failure

[tsoukalas]

Dear Sir,

Thank you for your reply and the documentation.
You are totally right, this is the good method to recalibrate a PDA. But in my case, the lambda 1 is in red and the access to save the calibration factors is not allowed. So i can t solve my issue.
I think the PDA is too far of the acceptance values.
But i am not sure of that...

Thank you for your help. Maybe do you have another idea for me.

[Hollow]

Dear Sir,
Thank you for your help. Maybe do you have another idea for me.

you're welcome.

if you can't save the new calibration values in service mode, then probably it's time to get in contact with Waters service.
That's something beyond my experience and I don't like to mess with the detectors optics.

[tsoukalas]

Thank you for you support.
I am waiting other answers, and if no one have the solution, i will call Waters.
Thanks again !
Pierre

[nkg]

is this a standard pda or elambda?

default values are:-
190.00/500.00 for standard (190-500nm )
188.00/802.00 for elambda (190-800nm )

try entering these whilst in service mode, you will then have to recalibrate

issue could have been with flat battery / firmware upgrade causing system to get wrong values

[Hollow]

with the values posted by nkg, I realize that the 190 nm value is off by about 10 nm.
This makes me think about blind optics. How old is your PDA and more important, what energy level do you have with pure Water or Methanol in the cell?
How do the several energy spectra (open, closed, erbium) look like? Anything suspicous there?

If the optics went blind in the low UV region, it may be that too low energy is read and the highest value in the Erbium spectra is recorded at your 200 nm diode?
Or about the first 8 diodes are gone / can't be read anymore by whatever reason.
...just guesses.

[Multidimensional]

My boss suggests that if the PDA is old (> 15 year), then one possible issue he has seen before is that the optics may be 'coated' from age (a normal process over time where a film builds up on them from the heating and cooling over time in the air, often dirty air from dirty filters) and this may result in the output being out-of-range for the onboard calibration. Many of the older detectors have this problem, but it depends on how many hours then were used and in what type of environment they were kept.

Make sure you are running the wavelength cal test with a verified clean (or new) flow cell filled with HPLC grade ACN, not MeOH (ACN is clear in the low UV, MeOH is not).

[Mattias]

I have had this error on even quite new Acquity PDA, and it has always been an issue of too low light intensity.

That is usually caused by a dirty flow cell, but it can also be a UV absorbing mobile phase (as suggested above) and of course if the lamp is too old.

For very old UV-detectors I have needed to change mirrors (since they get "burnt" and many 1000 hours of use)