Patent ID: 8773138

Claim:
A discharge ionization current detector for ionizing and detecting a sample component in a sample gas where the sample gas is ionized using plasma created by discharge, comprising: a) a plasma generation means causing a dielectric barrier discharge to be created by a low-frequency AC electric field in a first gas passage in which a plasma gas flows in one direction, so as to create a plasma from the plasma gas by the discharge; b) a second gas passage connected to an outlet end of the first gas passage, in which a dilution gas is caused to flow from an end opposed to the connection to the first gas passage in a direction opposite to a flow of the plasma gas; c) a sample gas introduction passage for introducing a sample gas into the second gas passage; d) an ion current detection means including an ion-collecting electrode and a bias voltage application electrode located apart from each other in a direction of the gas flow in the second gas passage, for detecting an ion current originating from the sample component in the sample gas ionized by an action of the plasma created by the plasma generation means; and e) a gas discharge passage connected to the second gas passage with an inlet end located between the ion-collecting electrode and the bias voltage application electrode, for discharging the plasma gas, the dilution gas and the sample gas from the second gas passage to an outside.