Chromatography Forum

Hi Guys!

We have Chromatographic system Agilenet 1260 infinity with diode array detector. We Bought that month ago. There is one problem, when I switch off lamp and after 20 second switch on, lamp don't ignition. In log file write retry ignition 2 times and than error. Error code is 7452. But when I switch off and after 6 minutes switch on lamp ignition. Such problem don't was in old agilent LC devises. Please tell me is that normal for DAD or that is detector board problem? Thank you

With regards

6 minutes is not a long time..

I don't know about that specific detector, but many optical devices have a temperature sensor which will not allow a lamp to fire until it has cooled down. Presumably this avoids stress on the lamp.

As I remember , there is a lamp type selection tab somewhere in software.
There are two different lamps which can be used in this detector , and you may select the lamp type ( by using catalog code of the lamp )

One type has a lower striking voltage around 300 volts , and the other one has a striking voltage of over 400 volts.

If the selection is 300 volts and your lamp needs 400 volts , it may not strike properly.

Tom is Correct. The lamp is simply too hot. The detector uses current through the lamp to confirm that the lamp has ignited. When the lamp is hot, the current is too low to confirm ignition. It nominally will take about 15 minutes to cool the lamp before re-ignition will work as expected.

The 7452 error is simply that the detector couldn't confirm lamp ignition, "UV ignition failed."

Dear Hexatriene ,

I don't think thats the case.
You assume that the detector uses current through the lamp cathode ( filament ) but it should be using the arc current to anode to confirm the lamp is ignited.

The detector tries to fire the lamp several times before giving an error , in approximately 20 seconds periods , and the filament is on during this process.

If your assumption is correct , the design engineers made a big mistake.

It nominally will take about 15 minutes to cool the lamp before re-ignition will work as expected. "

Dear hexatriene

Thank you for answer. Can you tell me where is these recommendation, that to cool take 15 min and than I can switch on the lamp? In Agilent 1100, 1200 we haven't such problem only for 1260.
Thank you all forum members for answer...

I have had 1100's and 1200's. They all have the same problem. UV won't ignite until it has a chance to cool off.

I have find official answer...
The processor monitors the UV lamp current during the ignition cycle. If the
lamp current does not rise above the lower limit within 2 – 5 seconds, the
error message is generated.
Probable Causes
• Lamp too hot. Hot gas discharge lamps may not ignite as easily as cold
lamps.
• Lamp not connected.
• Defective UV lamp or non-Agilent lamp.
• Defective detector main board.
• Defective power supply.
Suggested Actions
✔ Switch off the lamp and allow it to cool down for at least 15 minutes.
✔ Ensure the lamp is connected.
✔ Exchange the UV lamp.
✔ Exchange the detector main board.
✔ Exchange the power supply.