PDD (Pulsed Discharge Detector)

The VICI PDD (pulsed discharge detector) utilizes a stable, low-voltage, pulsed DC discharge in helium as an ionization source. Performance is equal to or better than detectors with conventional radioactive sources.

The PDD is available in two different modes:
In the electron-capture mode (ECD-Modus) the PDD is a selective detector for monitoring high electron affinity compounds such as freons, chlorinated pesticides, and other halogen compounds. It can be operated at temperatures up to 400°C. For operation in this mode, He with CH4 or Xenon dopant is introduced just upstream from the column exit. The minimum detectable quantity (MDQ) is at the femtogram(10^-15) or picogram (10^-12)level. Therefore, the PDD is similar in sensitivity and response characteristics to a conventional radioactive ECD.

In the helium photoionization mode the PDD is a universal, non-destructive, high sensitivity detector. The response to both inorganic and organic compounds is linear over a wide range. Response to fixed gases is positive (increase in standing current), with an MDQ in the low ppb range. In this mode, the PDD is an excellent replacement for flame ionization detectors FIDin petrochemical or refinery environments, where the flame and use of hydrogen can be problematic. In addition, when the helium discharge gas is doped with a suitable noble gas, such as argon, krypton, or xenon (depending on the desired cutoff point), the PDD can function as a specific photoionization detector for selective determination of aliphatics, aromatics, amines, as well as other species.

Deliviery of the detector system: contains detector cell, pulser, controller, electrometer, and helium purifier

PDD plug-in for Agilent 6890