Photo-ionization device with improved linearity and stability

A photo-ionization detector for testing gas, comprising:

• a gas ionization chamber having a set of stacked elements including:
• a first electrode;
• a fence electrode disposed below the first electrode;
• a second electrode disposed below the fence electrode;
• a first dielectric layer disposed between the first electrode and the fence electrode;
• and
• a second dielectric layer disposed between the fence electrode and the second electrode,
• wherein at least the first electrode, the second electrode, the first dielectric layer, and the second dielectric layer include a plurality of aligned holes forming channels configured to permit gas flow between the first electrode to the second electrode through an opening in the fence electrode, the plurality of aligned holes being arranged in a pattern having a central region with a first set of aligned holes and a peripheral region having a second set of aligned holes,
• wherein a diameter of multiple holes of the first set of aligned holes is less than or equal to about 0.5 millimeters;
• and
• a set of electrically conductive pins including:
• a first electrically conductive pin electrically connected to the first electrode;
• a second electrically conductive pin electrically connected to the fence electrode;
• and
• a third electrically conductive pin electrically connected to the second electrode, wherein the first, second, and third electrically conductive pins are arranged in a triangular pattern;
• an ionization light source positioned such that ionization light from the ionization light source is configured to pass through the plurality of the aligned holes for ionizing gas within the plurality of the aligned holes;
• and
• a circuit board electrically connected to both the ionization chamber and the ionization light source.

A photo-ionization detector for testing gas, comprising:

• a set of stacked elements including:
• a first electrode;
• a fence electrode disposed below the first electrode;
• a second electrode disposed below the fence electrode;
• a first dielectric layer disposed between the first electrode and the fence electrode;
• and
• a second dielectric layer disposed between the fence electrode and the second electrode,
• wherein at least the first electrode, the second electrode, the first dielectric layer, and the second dielectric layer include a plurality of aligned holes forming channels configured to permit gas flow between the first electrode to the second electrode through an opening in the fence electrode, the plurality of aligned holes being arranged in a pattern having a central region with a first set of aligned holes and a peripheral region having a second set of aligned holes,
• wherein a diameter of each hole of the first set of aligned holes is less than or equal to about 0.5 millimeters and a diameter of each hole of the second set of aligned holes is one of (a) less than or equal to about 0.5 millimeters or (b) greater than 0.5 millimeters;
• a first electrically conductive pin electrically connected to the first electrode;
• a second electrically conductive pin electrically connected to the fence electrode;
• a third electrically conductive pin electrically connected to the second electrode, wherein the first, second, and third electrically conductive pins are arranged in a triangular pattern;
• fourth and fifth electrically conductive pins electrically connected to the fence electrode;
• an ionization light source positioned such that ionization light from the ionization light source is configured to pass through the plurality of the aligned holes for ionizing gas within the plurality of the aligned holes,
• a circuit board electrically connected with the stacked elements via the first, second, third, fourth, and fifth pins, and electrically connected with the ionization light source, and
• a metallic enclosure with a top cap having a plurality of openings, wherein the metallic enclosure houses the ionization chamber, the ionization light source, and the circuit board, and wherein the plurality of openings allows the testing gas flowing through the ionization chamber.