Agilent Technologies 7890A Troubleshooting Manual page 25

Agilent 7890A Gas Chromatograph
Troubleshooting
3
Chromatographic Symptoms
Retention Times Not Repeatable 26
Peak Areas Not Repeatable 27
Contamination or Carryover 28
Larger Peaks Than Expected 30
Peaks Not Displayed/No Peaks 31
Baseline Rise During Oven Temperature Program 32
Poor Peak Resolution 33
Peak Tailing 34
Peak Boiling Point or Molecular Weight Discrimination Poor 35
Sample Decomposition in Inlet/Missing Peaks 36
Peak Fronting 37
Noisy Detector, Including Wander, Drift, and Baseline Spikes 38
Low Peak Area or Height (Low Sensitivity) 41
FID Flame Goes Out During a Run and Attempts to Reignite 43
FID Baseline Output Above 20 pA 44
FPD Flame Goes Out During a Run and Attempts to Reignite 45
FPD Output Too High or Too Low 46
FPD Low Peak Areas 47
FPD Large Peak Width at Half-Height 48
FPD Baseline Output High, > 20 pA 49
NPD Solvent Quenching 50
NPD Response Low 51
NPD Baseline Output > 8 million 52
NPD Adjust Offset Process Not Functioning Properly 53
NPD Low Selectivity 54
Negative Peaks Seen with TCD 55
TCD Baseline Has Dampened Sinusoidal Noise Trailing Peaks (Ringing
Baseline) 56
TCD Peaks Have Negative Dip on Tail 57
Agilent Technologies
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