Bad Deuterium Lamp out of Box but outside 90-day warranty

Please send an email LC-column-support@agilent.com with the order number.  They may be able to assist.  This e-mail is for US and Canada.

Hi Jason,

may i ask for what reason you declared this deuterium lamp as being bad?

There are several potential issues the lamp is not being responsible and the issue is more with the detector itself.  

Hi Jason,

it really would be great to receive some feedback from you to understand your concerns about the quality of your lamp.

A lamp for example would be technically bad if the lamp has been identified for being the root cause (major) contributor for:

- signal instabilities (drift &noise, peaks, signal fluctuation) that would have the detector failing the respective drift & noise test.

Always check the signal with having other components being removed from the optical path as much as possible (flow cell e.g. or with dedicated test flow cell in 1290 Infinity series detectors G4212X/G7117X).

When seeing strong and re-occuring signal fluctuations, also check the lamp voltage signal for signs of coincidences.

Signal fluctuations on the other hand also can be quite normal with lamps having a high burn time far beyond the guaranteed 2000h, so reliable lifetime tracking is very important and, in your case, the RFID tag in the 2140-0820 is doing this job.

- not getting ignited

Lamp must be cool, so trying to ignite a lamp that just got shut-off directly before typically does not work.

Detector.settings in configuration must match the the lamp type being used (with or without RFID tag e.g.)

The detector does not ignite the lamp as long as another module in the instrument is being in an error state (leak for example)

No lamp current possible in case the plug simply is not being plugged correctly (sometimes this just happens unnoticed)

- insufficient intensity

Here it is important to understand that the intensity test itself is being a module test and not an individual component test.

The test just provides you the information on the intensity that is being measured at the diodes at the very moment and very circumstances the test is being done.

So, the overall result is depending of course on the lamp but mainly on the performance and condition of all the optical components in the light path.

These components are degrading over the time and sooner or later it may happen that the test will fail even with a lamp having a lifetime below 2000 hours.

This is especially true for seeing a fail in the range of 190 - 210 nm as the lamp intensity is degrading stronger in the lower WL ranges than the higher ones.

The test anyway only should be performed in case you are observing chromatographic issues with your instrument like noise (low signal to noise ratio) and you want to find out the potential root cause.

Performing the cell test in addition provides you the information on the contribution of your flow cell to your optical performance and indicates if the flow cell may require some maintenance or should get replaced.

An intensity test that is failing in more than one WL-ranges can have several root causes:

Performance of optical components very low.

Absorbing solvent or air bubble in the flow cell.

Flow cell not correctly seated.

Lamp not correctly seated (180° turned e.g.) especially if the test shows some negative values.

Misaligned internal components resulting from shock impact at transport or otherwise bad handling.

In this case also the light of the Vis-lamp would be impacted.

For identifying the lamp as being the major contributor to the low intensity readings it therefore would not be sufficient to just use a new lamp and see if this does not fail.

It most probably will not fail but very likely with intensity just below the test limits.

For a full root cause identification, it would be required to also have the critical optical components getting renewed and very likely the intensity gain will be much higher and sustainable.