A dielectric barrier discharge ionization detector Includes: a dielectric tube; a high-voltage electrode connected to an AC power source and circumferentially formed on the outer wall of the dielectric tube; upstream-side and downstream-side ground electrodes and circumferentially formed above and below the high-voltage electrode; a discharging section for generating electric discharge to create plasma, from a gas containing argon; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting an ion current formed by the ionized components. The detector also satisfies one or both of the following conditions: the upstream-side ground electrode is longer than a creeping discharge initiation distance between a tube-line tip member at the upper end of the dielectric tube and the high-voltage electrode; or the downstream-side ground electrode is longer than a creeping discharge initiation distance between the high-voltage electrode and the charge-collecting section.

The dielectric barrier discharge ionization detector includes: a dielectric tube through which a plasma generation gas is passed; a high-voltage electrode formed on the outer wall of the dielectric tube; two ground electrodes and formed on the outer wall of the dielectric tube, with the high-voltage electrode in between; a voltage supplier for applying AC voltage between the high-voltage electrode and each ground electrode to generate electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas; and a charge-collecting section for detecting an ion current formed by ionized sample-component gas produced by the plasma. The distance between one ground electrode and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while the distance between the other ground electrode and the high-voltage electrode is shorter than the discharge initiation distance between these two electrodes.

The dielectric barrier discharge ionization detector includes: a dielectric tube through which a plasma generation gas is passed; a high-voltage electrode formed on the outer wall of the dielectric tube; two ground electrodes and formed on the outer wall of the dielectric tube, with the high-voltage electrode in between; a voltage supplier for applying AC voltage between the high-voltage electrode and each ground electrode to generate electric discharge within the dielectric tube and thereby generate plasma from the plasma generation gas; and a charge-collecting section for detecting an ion current formed by ionized sample-component gas produced by the plasma. The distance between one ground electrode and the high-voltage electrode is longer than a discharge initiation distance between these two electrodes, while the distance between the other ground electrode and the high-voltage electrode is shorter than the discharge initiation distance between these two electrodes.

A dielectric barrier discharge ionization detector includes: a discharging section for generating plasma from argon-containing gas by electric discharge, including a dielectric tube on the outer wall of which a high-voltage electrode connected to AC power source as well as upstream-side and downstream-side ground electrodes and are circumferentially formed; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting ion current formed by ionized components. The dielectric tube is made of a material whose resistivity is 1.010.sup.13 cm or lower. Furthermore, the detector satisfies at least one of the following conditions: the upstream-side ground electrode is longer than a ground electrode length which allows creeping discharge between the high-voltage electrode and a tube-line tip member; or the downstream-side ground electrode is longer than a ground electrode length which allows creeping discharge between the high-voltage electrode and the charge-collecting section.

A dielectric barrier discharge ionization detector includes: a discharging section for generating plasma from argon-containing gas by electric discharge, including a dielectric tube on the outer wall of which a high-voltage electrode connected to AC power source as well as upstream-side and downstream-side ground electrodes and are circumferentially formed; and a charge-collecting section for ionizing sample-gas components by the plasma and detecting ion current formed by ionized components. The dielectric tube is made of a material whose resistivity is 1.010.sup.13 cm or lower. Furthermore, the detector satisfies at least one of the following conditions: the upstream-side ground electrode is longer than a ground electrode length which allows creeping discharge between the high-voltage electrode and a tube-line tip member; or the downstream-side ground electrode is longer than a ground electrode length which allows creeping discharge between the high-voltage electrode and the charge-collecting section.

An ionization device includes a first electrode comprising a conductive member coated with a dielectric layer. The ionization device also includes a spine extending adjacent to and at least partially along the first electrode. The ionization device further includes a second electrode comprising conductive segments disposed adjacent the first electrode. Each one of the conductive segments contacts the spine at a respective contact location. The dielectric layer of the first electrode separates the conductive member of the first electrode from the spine and the second electrode. The ionization device is configured to create plasma generating locations corresponding to respective crossings of the first electrode and the second electrode.

An ionization device includes a first electrode comprising a conductive member coated with a dielectric layer. The ionization device also includes a spine extending adjacent to and at least partially along the first electrode. The ionization device further includes a second electrode comprising conductive segments disposed adjacent the first electrode. Each one of the conductive segments contacts the spine at a respective contact location. The dielectric layer of the first electrode separates the conductive member of the first electrode from the spine and the second electrode. The ionization device is configured to create plasma generating locations corresponding to respective crossings of the first electrode and the second electrode.

A method for analyzing ionic structure, including: applying a radio frequency electric field on an ion mass analyzer to cause sample ions to be excited to a motion amplitude, the motion amplitude at this moment being recorded as a primary motion amplitude; continuously feeding carrier gas into the ion mass analyzer and keeping a certain degree of vacuum in the ion mass analyzer, the sample ions being collided with the carrier gas and the motion amplitude being decreased gradually, and collecting a time domain signal of an image current generated by the sample ions during the process; and analyzing the time domain signal through a time-frequency analysis method and obtaining time-varying characteristic curves indicating corresponding relations between the motion frequencies of the ions having corresponding sizes and the collision cross sectional areas of the ions and the carrier gas, thus distinguishing among ions having different sizes.

Particulate measurement processing executed by a sensor control section of a particulate measurement system includes a step of stopping voltage conversion by a first isolation transformer and a second isolation transformer, a step of obtaining correction information B, and a step of correcting ion current A through use of the correction information B. The correction information B reflects improper current generated through particulates, etc. (soot or the like) adhering to a particulate sensor. The ion current A (signal current I.sub.esc) is corrected through use of the correction information B, and the amount of soot S is computed through use of the corrected ion current A. As a result, it is possible to measure the amount of the soot S (the amount of particulates) while suppressing the influence of the improper current.

Particulate measurement processing executed by a sensor control section of a particulate measurement system includes a step of stopping voltage conversion by a first isolation transformer and a second isolation transformer, a step of obtaining correction information B, and a step of correcting ion current A through use of the correction information B. The correction information B reflects improper current generated through particulates, etc. (soot or the like) adhering to a particulate sensor. The ion current A (signal current I.sub.esc) is corrected through use of the correction information B, and the amount of soot S is computed through use of the corrected ion current A. As a result, it is possible to measure the amount of the soot S (the amount of particulates) while suppressing the influence of the improper current.