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High baseline in PDHID detector

Question asked by serdarche on Jan 29, 2020
Latest reply on Apr 20, 2020 by james_jenkins

Hi dear community members!


There is a 7890B GC-PDHID (Vici Valco) system laboratory of a polymer plant. It is configured as per ASTM D2504 (purged packed inlet, gas sampling valve, packed column). For determination of CO, CO2 in ethylene. The PDHID has high baseline 12000-17000 pA. According to operation manual it should be 600-2000 pA. One portion of the carrier and discharge gas was copper, I replaced with stainless steel. However this did not help. I disconnected the column from the detector and plugged the detector. This did not improve the baseline neither. Any other suggestions would be useful.