892J009MNAE | DBDID | 5
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1. Introduction
This service instruction is for reference when installing, operating, and servicing the ABB PGC5000
Dielectric Barrier Discharge Ionization Detector (DBDID). It is for use only by qualified personnel.
– Bodily injury. Servicing of this product shall be performed by individuals who
are knowledgeable of the procedures, precautions, and hazards associate
d with equipment
containing hazardous energy circuits.
1.1 Usage
Dielectric Barrier Discharge Ionization Detector (DBDID) is used in the ABB PGC5000 Process Gas
Chromatograph.
It is used to detect parts per billion (ppb) and parts per million (ppm) concentrations of the following
applications:
Impurities in high purity gases and products
Halogenated hydrocarbons
BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes)
Arsine and phosphine
Ethylene oxide
Ammonia
Nitric oxide in cold box applications
Ambient air applications
1.2 Measurement Principle
The dielectric barrier is a plasma discharge obtained using a high voltage alternating current applied
to a gas as it flows through a dielectric material. The gas is typically helium or argon, and the
dielectric material is a quartz or Pyrex tube.
Two electrodes are arranged within the detector. When high voltage is applied to the gas, a
breakdown occurs with a subsequent discharge from one electrode to the other electrode. The
presence of the dielectric barrier behaves as a capacitor in the localized region of the discharge. As
such, the dielectric barrier stores a substantial amount of energy for each discharge resulting in the
generation of highly excited state of the helium (or argon) atoms. This is called the reaction gas.
The sample components are ionized when they elute from the column. A second set of electrodes
measures the current generated from these ionized components. The output is sent to an
electrometer where it is amplified, measured, and displayed.
Figure 1-1: Dielectric Barrier Discharge Ionization Detector
2 Service and maintenance
The following chapter includes a list of replacement parts, instructions for replacing spare parts, and
other maintenance procedures for the Dielectric Barrier Discharge Ionization Detector (DBDID).
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