Discharge Ionization Detector Partition Design for Noise Reduction

Solution Overview

Problem

Conventional discharge ionization current detectors using low frequency alternating current exciting dielectric barrier discharge suffer from noise due to air entering through the connection portion between the tubular body and the tubule for introducing a sample gas, which affects the detector's output.

Innovation Solution

A discharge ionization current detector design featuring a partition with a through hole between the collector electrode and the gas outlet, where the tubule penetrates, and a cylindrical portion surrounding the through hole to direct the plasma-generating gas flow towards the outlet, preventing air from reaching the collector electrode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a ferrule joint is used for connecting the tubule to the tubular body, then the connection is easy to make and remove, but air may enter through the connection portion causing noise in the detector output

Engineering Contradiction:

Improveease of connectionVSAvoidnoise

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The detector is divided into two separate chambers by a partition: a plasma generation chamber and a detection chamber. The partition has a through-hole that allows the tubule to pass through, creating separate zones that prevent air leakage from affecting the detection region while maintaining connection accessibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The partition acts as an intermediary structure between the connection region and the detection region. It includes a through-hole for gas passage and a cylindrical portion that surrounds the tubule, serving as a barrier that prevents air entering at the connection point from reaching the collector electrode.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If the tubule is connected at the end of the tubular body, then the structure is simple, but air entering through the connection can reach the collector electrode and cause noise

Engineering Contradiction:

Improvestructural simplicityVSAvoidnoise

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The detector is divided into two separate chambers by a partition: a plasma generation chamber and a detection chamber. The partition has a through-hole that allows the tubule to pass through, creating separate zones that prevent air leakage from affecting the detection region while maintaining connection accessibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The partition extends in the axial direction of the tubular body, creating a spatial separation between the connection region and detection region. This dimensional arrangement ensures that air entering at the connection point is directed toward the gas outlet rather than the collector electrode.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Measurement precision

If high sensitivity detection is required, then the detector must be highly sensitive to trace gases, but this makes it more susceptible to noise from air contamination

Engineering Contradiction:

Improvedetection sensitivityVSAvoidnoise

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The detector is divided into two separate chambers by a partition: a plasma generation chamber and a detection chamber. The partition has a through-hole that allows the tubule to pass through, creating separate zones that prevent air leakage from affecting the detection region while maintaining connection accessibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The design converts the potential harmful effect of air entering at the connection point into a beneficial outcome by directing it toward the gas outlet. The partition structure ensures that air entering through the connection is channeled out through the outlet rather than reaching the collector electrode, thus preventing noise while maintaining high sensitivity.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design effectively discharges any entering air without causing noise in the detector's output, maintaining high sensitivity and allowing for easy connection and removal of the tubule using a ferrule joint.

Implementation Method 1

a discharge ionization current detector or a detector that is referred to as a barrier discharge ionization detector (BID)

Methodology Applied

Scientific EffectDielectric barrier discharge: Electric Arc

Implementation Method 2

ionizing the sample gas using plasma that has been generated by applying a low frequency, alternating current voltage to the electrode for discharge

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 3

ionizing the sample gas using plasma... and then, the component molecules of the sample gas are ionized due to the effects of the light released from the plasma or the excited species of helium

Methodology Applied

Scientific EffectIonization: Ionisation

Implementation Method 4

These ions are attracted to the bias electrode 47 to which a direct current bias voltage is applied, and furthermore are collected by the collector electrode 48

Methodology Applied

Scientific EffectIon attraction: Ion Repulsion/Attraction

Data Source

PatentUS9285344B2Discharge ionization current detector and gas chromatograph

Publication Date: 2016.03.15 SHIMADZU CORP

AI summary

To provide a discharge ionization current detector 3, where a partition 13a in which a through hole for penetrating a tubule 24 for introducing a sample gas is created is provided between a collector electrode 20 and an outlet for discharging a gas 26 so that a gas for generating plasma that has been generated by electrodes for discharge 15, 16 and 17 passes through a gap between the through hole and the tubule 24 so as to be directed towards the outlet for discharging a gas, and thus, the air that has entered from the other side 25 of the partition cannot pass through the through hole in the opposite direction.