ABB DBDID Process gas chromatographs
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—
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 reac tion 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 electro meter where it is amplified.

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.—Safety area classificationNEC
Class I, Division 2 Group B, C, D with Type X-Purge T4, T3, or T2
Conforms to ATEX directive 2004/108/EC
Zone 2: CE; II 3G Ex px d [ib] ib IIB+H2 T4, T3, or T2 with
Type X-Purge—PowerVoltage
Plasma reactor 12V, 1.0A Total power consumption less
than 20 Watts.X-Purge timeout
4.6 minutes @ 60 Hz, 5.5 minutes @ 50 Hz Note
T-code and protection method are dependent
upon application.—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.
Detector sensitivity
NoteSensitivity is a function of the total application design. It
depends on the mode of operation and on the ionization
potential of the analyte. Sensitivity values are given with 4
to 1 minimum signal to noise ratios.
Helium ionization mode
Sensitive to fixed gases down to about 0.5 ng on column,
using hydrogen as the indicator.
Argon ionization mode
Sensitive to benzene down to 20 picograms.—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—Utility Specification
Helium ionization mode
Minimum of Grade 5 helium for carrier and reactor gas
supplies.
Argon ionization mode
Minimum of Grade 5 helium, nitrogen, or hydrogen for
carrier supply.
Minimum of Grade 5 or argon for carrier supply.