ASTM Drift and Noise Test Failed

Question

Hello, 
 I have been performing ASTM Drift and Noise Test on 1260 Infinity II DAD WR (G7115A) since yesterday, the results are the same - Noise failes at 254 nm (or so 0.03mah). 
 Module is new (less than 1 year). 
 In the last time I have performed Qualification, I also had the problem, I changed the lamp and test passed, but with many afforts (maybe once per 10 times). On this time, there were drift issues too. 
 In addition, I do tests without flow cell. 
 Could you please advise what should I do.

sschombu · Accepted Answer

Your last test results are not awfully bad. How does the intensity test look? Maybe the system just needs to be flushed/equilibrated a little longer? 
 Did you pay attention to this section in the manual? 
 
 ASTM drift tests require a temperature change below 2 &deg;C/hour (3.6 &deg;F/hour) over one hour period. Our published drift specification is based on these conditions. Larger ambient temperature changes will result in larger drift. Better drift performance depends on better control of the temperature fluctuations. To realize the highest performance, minimize the frequency and the amplitude of the temperature changes to below 1 &deg;C/hour (1.8 &deg;F/hour). Turbulences around one minute or less can be ignored. Performance tests should be done with a completely warmed up optical unit (> two hours). ASTM measurements require that the detector should be turned on at least 24 h before start of testing.

sschombu · Answer

The test can be done with or without flow cell. Like I said, the last test didn't look awfully bad to me (remember, a failed test in LabAdvisor doesn't necessarily indicate a real problem or even hardware failure). 
 
 Check your environmental conditions, maybe there's a massive draft from the A/C, direct sunlight etc. An intensity test would be useful to get an idea about the detector performance in general. Make sure you use the correct lamp from Agilent and its screws are tight (but not "gorilla-ed" in). 
 
 If the module is less than one year old, you still have warranty, so call your local Agilent office, if you need additional help.

ASTM Drift and Noise Test Failed

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