UV Lamp hours keep  increasing when HPLC system is at standby mode

Hello,

thanks for update (I wonder if my memories were incorrect,,,

Your question is classed "difficult" ......

Let me start easier one!  The visible lamp is not required replacing.  It seems working without error. that is typical "bulb" , if id is out the software tells you "current error" or something , (not like ignition error)

The UV lamps age ,in general, the lifetime is around 2000h as you know,

The 8100h is surprise! (Or someone missed to reset lamp hours! So today's DAD lamps have RFID tag recording correct "ITS" hours, as jhagel wrote , RFID information is reliable.)

Your test result tells us "the light intensity is low", possible causes are:

- aged lamp

- something in the cell (UV absorbing solvent, bubbles or everything to hide beam!)

- dirty flow cell windows

- dirty or aged windows/lens of optical unit

- other malfunction

And your detector is old model (as sschombu wrote)

Replacing to new genuine lamp is good idea in many cases :-) but sometimes  NOT for aged detector, If lens/windows/cell/windows/grating are dirty or burnt and you replace NEW-lamp, the light intensity will not recover and intensity test will fail. In this case you need to ask to repair of DAD. (and you can't return new-lamp... )

I have no idea for repair parts availability (some are already gone...), so I recommend to ask local Agilent's service..., 

possibility ,price, parts availability and risk of costs.

In some cases you have no need to replace UV lamp:

- you can do your analysis without any problem.

- your chromatogram's noise is within YOUR specification

- your chromatogram have now explicit drift or hiccup

- your boss/customer/regulations permits use of old lamp.

Sorry for complicated advices ,

Regards,

ps : If it's mine I will try to wipe two window in cell compartment with a clean wipe and non-metal toothpick..... only two window in cell room ! and leave it half day. I can't give you guarantee...

Hello,

thanks for update (I wonder if my memories were incorrect,,,

Your question is classed "difficult" ......

Let me start easier one!  The visible lamp is not required replacing.  It seems working without error. that is typical "bulb" , if id is out the software tells you "current error" or something , (not like ignition error)

The UV lamps age ,in general, the lifetime is around 2000h as you know,

The 8100h is surprise! (Or someone missed to reset lamp hours! So today's DAD lamps have RFID tag recording correct "ITS" hours, as jhagel wrote , RFID information is reliable.)

Your test result tells us "the light intensity is low", possible causes are:

- aged lamp

- something in the cell (UV absorbing solvent, bubbles or everything to hide beam!)

- dirty flow cell windows

- dirty or aged windows/lens of optical unit

- other malfunction

And your detector is old model (as sschombu wrote)

Replacing to new genuine lamp is good idea in many cases :-) but sometimes  NOT for aged detector, If lens/windows/cell/windows/grating are dirty or burnt and you replace NEW-lamp, the light intensity will not recover and intensity test will fail. In this case you need to ask to repair of DAD. (and you can't return new-lamp... )

I have no idea for repair parts availability (some are already gone...), so I recommend to ask local Agilent's service..., 

possibility ,price, parts availability and risk of costs.

In some cases you have no need to replace UV lamp:

- you can do your analysis without any problem.

- your chromatogram's noise is within YOUR specification

- your chromatogram have now explicit drift or hiccup

- your boss/customer/regulations permits use of old lamp.

Sorry for complicated advices ,

Regards,

ps : If it's mine I will try to wipe two window in cell compartment with a clean wipe and non-metal toothpick..... only two window in cell room ! and leave it half day. I can't give you guarantee...

Hello everyone,

Are there any "correct" comments ???

Regards,