Agilent Technologies 7890A Troubleshooting Manual page 40

3
Chromatographic Symptoms
Baseline spiking
40
There are two types of spiking on the baseline output: cyclic
and random.
Figure 1 Cyclic spiking
Cyclic spiking can be caused by the following:
• An electric motor
• Building heating/cooling system
• Other electronic interferences in the lab
Figure 2 Random spiking
Spikes are isolated baseline disturbances, usually appearing
as sudden (and large) upscale movements. If accompanied by
noise, resolve the noise problem first since spiking may
disappear at the same time.
• Check for a contaminated detector.
• For a packed column, check that the packed column exit
is properly sealed with glass wool.
• Check packed column installation.
• Check for the correct jet.
Troubleshooting