Paramount 9000 GC-PDD (P9000P) is a process gas chromatograph (GC) coupled with a Pulsed Discharge Detector (PDD) specifically engineered for detecting trace level of Ar and N2 in UHP bulk gases. The core technology of this PDD is a stable helium plasma generated by a low power pulsed DC discharge. While operated in the helium photoionization mode, the PDD is an excellent ppb level GC detector for fixed gases. Every P9000P trace gas analyzer also futures a helium purged GC chamber to ensure the excellent sensitivity of PDD is not compromised

A helium gas discharge produces high energy photons

He2*         2 He + hν (13.5 eV – 17.7 eV)

Sample atoms or molecules are ionized by these high energy photons (photoionization) and the resulting electrons are collected

M + hν             M+ + e

Paramount 9000 GC-PDD