ABB DBDID Process gas chromatographs

ABB DBDID  Process gas chromatographs

Description

A dielectric barrier discharge is a plasma  discharge that is obtained using a high voltage  alternating current applied to a gas such as  Helium or Argon as it flows through a dielectric  material such as quartz glass. Two electrodes are  arranged within the detector so that when the  high voltage is applied to the gas, a breakdown  occurs with a subsequent discharge from one  electrode to the other. The presence of the  dielectric barrier behaves as a capacitor in the  localized region of the discharge. The dielectric  barrier stores a substantial amount of energy for  each discharge which results in the generation of  highly excited state molecules and atoms of  Helium or Argon which is referred to as the reaction gas. As the sample components elute from  the column they are ionized by the reaction gas  and a second set of electrodes in the detector  measures the current generated from the ionized  components. The output is sent to an electrometer where it is amplified.

Application

Usage 

The Dielectric Barrier Discharge Ionization  Detector (DBDID) is used in ABB analytical process  gas chromatographs for parts-per-billion (ppb)  and parts-per-million (ppm) measurements of  the following: 

• Impurities in high purity gases  

• Halogenated hydrocarbons  

• Impurities in ethylene  

• Low levels of BTX  

• Arsine and phosgene  

• Ammonia 

• Nitric oxide

Specification

Environmental (enclosure)

The device is only suitable for use in clean dry areas.

Operation temperature range

+50 to +150 °C (122 to 302 °F)

Installation and mounting

Integrated and configured with the PGC2000 and  PGC5000 series process gas chromatographs.

Gas consumption

Reaction gas flow

Helium mode: 100 ml/min

Argon mode: 5-20 ml/min

Carrier gas flow

Packed columns: 20-60 ml/min per analytical valve

Modes of operation

Helium ionization mode

In this mode the detector is sensitive to all organic and  inorganic volatile components except neon. Operating in  this mode, sub parts per million levels of fixed gases can  be easily measured.

Argon ionization mode

In this mode the detector is not sensitive to fixed gases  and methane but it is sensitive to a wide range of organic  and inorganic volatile components. It is capable of ionizing  any component with an ionization potential less than 11.5  eV. This is an excellent detector for compounds such as  BTEX compounds.

High voltage alternating current plasma discharge

• Helium or argon ionization modes  

• New industry applications for ppm and  ppb measurements  

• Impurities in high purity gases  

• Halogenated hydrocarbons  

• Impurities in ethylene  

• Low levels of BTX  

• Arsine and phosgene  

• Ethylene oxide  

• Formaldehyde  

• Ammonia