Planar photoionization detector and planar photoionization detector sensor

Abstract

The present invention provides a planar photoionization detector and a planar photoionization detector sensor, the planar photoionization detector comprising: a gas discharge lamp that ionizes a molecule of interest to produce ionized molecules and electrons; and a sensor having at least one opening for passage of UV light, and a conductive pattern on at least one of a top surface and a bottom surface of the plate, the conductive pattern including at least a negative potential pattern and a collector pattern. The ionized molecules may be collected by a bias electrode and electrons may be collected by a collector. The negative potential pattern includes a linear portion and a polarizing plate. The collector pattern includes a conductive line suspended across the at least one opening and a linear portion located on a surface opposite the conductive line. The conductive pattern may further include a ground potential conductive pattern having a first portion on the top surface and a second portion on the bottom surface.

Description

Technical Field

[0001] The present disclosure relates to an improved photoionization detector. More specifically, it relates to a photoionization detector sensor having a unique electrode pattern that increases the strength of the detection signal while minimizing the sensor's sensitivity to humidity. Background Art

[0002] Photoionization detectors (PIDs) are handheld, portable gas detectors used to measure volatile organic compounds (VOCs) such as benzene and other organic gases by ionizing ambient gases and measuring the resulting electrons. PIDs can produce instantaneous readings and can operate continuously, making them useful in monitoring health and safety in military, industrial, and confined work facilities. However, there are various obstacles in current technology.

[0003] In one example, a PID with high VOC gas sensitivity often amplifies unwanted system and background noise. More specifically, the electronics in the PID convert the collected electron current into a voltage, and if the PID has a high sensitivity, the burden on these electronics is reduced. To produce this high sensitivity, PIDs traditionally use transimpedance amplifiers (TIAs). However, these amplifiers increase system and background noise in addition to the VOC signal. Therefore, it is desirable to reduce the need to use a transimpedance amplifier and thus achieve a higher gain detector with improved PID signal-to-noise performance.

[0004] In another example, if a conventional PID sensor is used outside of a controlled laboratory environment, it is often affected by humidity. Since PID sensors are capable of generating current levels as low as the femtoampere range that are proportional to the concentration of the ionized gas being measured, the electrokinetic current generated in the presence of an electrolyte that bridges two conductors containing different materials is a potential source of error in PID sensors and therefore limits the sensitivity of the detector. More specifically, when exposed to UV light, humidity may generate hydroxyl molecules that can directly participate in conduction or can change the conductive properties of the material in contact with it. This conductive medium is a problem when bridging the collector node and any other node having a different potential from the collector node. Therefore, an improved sensor is needed that maximizes the gap and distance between all electrodes so that it has a minimum shared contact area and allows a more accurate and sensitive detector that can be used in more extreme (i.e., humid) environments. Summary of the invention

[0005] The present disclosure relates to a photoionization detector sensor having a unique electrode pattern that increases the strength of the detection signal while minimizing the sensor's sensitivity to humidity. In an illustrative but non-limiting example, the present disclosure provides a planar photoionization detector that may include a gas discharge lamp and a sensor that ionizes molecules of interest to produce ionized molecules and electrons, the sensor including at least one plate having at least one opening and a conductive pattern located on at least one of the top and bottom surfaces of the plate, the conductive pattern including at least a negative potential pattern and a collector pattern, wherein the collector pattern may include a wire suspended across the at least one opening. The plate may include an electrically insulating substrate, and the at least one opening may allow UV light to pass through.

[0006] In some cases, the conductive pattern may further include at least one conductive pattern maintained at an electrical ground potential. The planar photoionization detector may further include a feedthrough pin, the feedthrough pin being electrically connected to the collector pattern. The ground potential conductive pattern may be positioned on the same board surface as the negative potential pattern, and the ground potential conductive pattern may be located between the negative potential pattern and the collector feedthrough pin. Further, the planar photoionization detector may include a second ground potential conductive pattern located on a surface opposite to the ground potential conductive pattern. The second ground potential conductive pattern may be located between the collector pattern and the feedthrough pin, and the feedthrough pin may be electrically connected to the negative potential pattern. In some cases, the second ground potential conductive pattern surrounds the at least one opening.

[0007] In some embodiments in which the conductive pattern may further include at least one conductive pattern maintained at an electrical ground potential, the ground potential conductive pattern may include a first portion positioned on the same plate surface as the negative potential pattern and a second portion positioned on the plate surface opposite to the negative potential pattern, and a portion of the second portion of the ground potential conductive pattern may surround the at least one opening. Additionally, the negative potential pattern may include a polarizing plate, and a portion of the second portion of the ground potential conductive pattern surrounding the at least one opening may be aligned with the polarizing plate and a portion of the first portion of the ground potential conductive pattern.

[0008] In some cases, the negative potential pattern can be located on one of the top surface or the bottom surface. Additionally, the negative potential pattern can include a polarizing plate. Further, the polarizing plate can be adjacent to and along the length of at least one opening.

[0009] In other cases, the collector pattern may include a linear pattern located on one of the top surface or the bottom surface of the board, and the wire suspended across at least one opening may be located on the other of the top surface or the bottom surface. Further, the conductive pattern may further include at least one conductive pattern maintained at an electrical ground potential, and the ground potential conductive pattern may be interposed between the linear pattern of the collector pattern and at least one opening. In some cases, the wire may be connected to a first opening near the first side of the board at a first end, the wire may be connected to a second opening near the second side of the board at a second end, and the second opening may also be connected to the end of the linear pattern of the collector pattern, thereby connecting the wire to the linear pattern. In some cases, the wire may include multiple wires.

[0010] In some cases, at least one opening in the plate can be a single opening. In other cases, at least one opening can include a plurality of openings. The electrically insulating substrate of the plate can be polytetrafluoroethylene. In some cases, the plate can be a single hydrophobic layer having a negative potential pattern deposited on the top surface, a ground potential conductive pattern deposited on the top and bottom surfaces, and a collector pattern deposited on the bottom surface and including a suspended wire located on the top surface.

[0011] In another illustrative but non-limiting example, the present disclosure provides a planar photoionization detector sensor that may include a plate having a top surface and a bottom surface and including an electrically insulating substrate, an opening for passing UV light, a negative potential pattern including a linear portion and a polarizing plate, a collector pattern including a wire suspended across the opening, and a ground potential conductive pattern having a first portion located on the top surface and a second portion located on the bottom surface. Various additional limitations may exist. For example, the polarizing plate may be adjacent to the length of the opening and extend along the length of the opening, the ground potential conductive pattern may be inserted between the negative potential pattern and the collector feedthrough pin, the wire may be connected at its end to a wire opening positioned at either end of the opening, the ground potential conductive pattern may be inserted between the wire opening and the opening, the second portion of the ground potential conductive pattern may surround the opening, the lower portion of the second portion of the ground potential conductive pattern may be a UV blocking electrode, the UV blocking electrode is adjacent to the length of the opening and extends along the length of the opening, and the polarizing plate located on the top surface may be substantially aligned with the UV blocking electrode located on the bottom surface.

[0012] In another illustrative but non-limiting example, the present disclosure provides a planar photoionization detector sensor, which may include a board having a top surface and a bottom surface and including an electrically insulating substrate, at least one opening for allowing UV light to pass through, a negative potential pattern located on one of the top surface or the bottom surface, and a collector pattern having a wire suspended across the at least one opening, wherein the wire may be suspended across the same board surface where the negative potential pattern is located. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of a photoionization detector.

[0014] FIG. 2a is an exploded view of a prior art photoionization detector.

[0015] 2b is a bottom view of a prior art photoionization detector sensor of the detector of FIG. 2a.

[0016] Figure 3 is a schematic top view of a first embodiment of a photoionization detector sensor according to the present disclosure.

[0017] Figure 4 yes Figure 3 Schematic bottom view of a photoionization detector sensor.

[0018] Figure 5 yes Figure 3-Figure 4 Schematic cross-sectional side view of a photoionization detector sensor illustrating where UV light enters the sensor.

[0019] Figure 6 yes Figure 5 A cross-sectional view of a portion of the Figure 3-Figure 4 The electric field lines generated by the photoionization detector sensor.

[0020] Figure 7 is a schematic top view of a second embodiment of a photoionization detector sensor according to the present disclosure.

[0021] Figure 8 yes Figure 7 Schematic bottom view of a photoionization detector sensor.

[0022] Fig. 9 yes Figure 7 Side view of a cross section of a photoionization detector sensor, illustrating where UV light enters the sensor.

[0023] Fig.10 yes Fig. 9 A cross-sectional view of a portion of the Figure 7 The electric field lines generated by the photoionization detector sensor. DETAILED DESCRIPTION

[0024] The present disclosure relates to a photoionization detector (PID) sensor having a unique electrode pattern that increases the intensity of the detection signal while minimizing the sensor's sensitivity to humidity. Various embodiments of the PID sensor will be described in detail with reference to the accompanying drawings, wherein similar reference numerals represent similar parts and assemblies in several views. Reference to various embodiments does not limit the scope of the PID sensor disclosed herein. In addition, any examples set forth in this specification are not intended to limit and only set forth some of the many possible embodiments for the PID sensor. It should be understood that various omissions and substitutions of equivalents are contemplated when circumstances may indicate or present as advantageous, but these omissions and substitutions are intended to cover applications or embodiments without departing from the spirit or scope of the present disclosure. It should also be understood that the wording and terminology used herein are for illustrative purposes only and should not be considered restrictive.

[0025] Figure 1-Figure 10 Various views of elements of a photoionization detector according to the present disclosure are illustrated. Figure 1 is a schematic diagram of a photoionization detector. Figure 2a is an exploded view of a prior art photoionization detector. Figure 2b is a bottom view of a prior art photoionization detector sensor of the detector of Figure 2a. Figure 3 is a schematic top view of a first embodiment of a photoionization detector sensor according to the present disclosure. Figure 4 yes Figure 3 Schematic bottom view of a photoionization detector sensor. Figure 5 yes Figure 3-Figure 4 Schematic cross-sectional side view of a photoionization detector sensor illustrating where UV light enters the sensor. Figure 6 yes Figure 5 A cross-sectional view of a portion of the Figure 3-Figure 4 The electric field lines generated by the photoionization detector sensor. Figure 7 is a schematic top view of a second embodiment of a photoionization detector sensor according to the present disclosure. Figure 8 yes Figure 7 Schematic bottom view of a photoionization detector sensor. Fig. 9 yes Figure 7 Side view of a cross section of a photoionization detector sensor, illustrating where UV light enters the sensor. Fig.10 yes Fig. 9 A cross-sectional view of a portion of the Figure 7 The electric field lines generated by the photoionization detector sensor.

[0026] Some embodiments of the PID disclosed herein include a sensor having two or more electrodes, a gas discharge lamp, and an amplifier connected to one of the two or more electrodes. The two or more electrodes of the PID sensor may include a collector, a negative bias electrode, a ground electrode, and combinations thereof (e.g., a collector and a ground electrode). The negative bias electrode and the collector may support an electrostatic field. The ground electrode may establish a low impedance path back to the power supply to facilitate operation of the device by intercepting current that may occur between the negative bias electrode and the collector (typically configured as a guard trace) and establishing a stable ground voltage during operation.

[0027] like Figure 1 As illustrated, the gas discharge lamp 102 can ionize molecules of interest 104 (e.g., VOC gas molecules) to produce ionized molecules 106 and electrons 108. More specifically, when the UV light source in the gas discharge lamp 102 is activated, it can ionize ambient gases (e.g., VOC gases) and produce ionized molecules 106 and electrons 108. The ionized molecules 106 can be collected by the negatively biased electrode 110, and the electrons 108 can be collected by the collector electrode 112.

[0028] The collector electrode 112 may be connected to an amplifier 114, which may be a high gain transimpedance amplifier (TIA) that measures the electrons 108 generated from the ionized gas and provides a measurement proportional to the gas concentration in the environment. When the gas 104 is ionized, the generated electrons 108 may be accelerated to the collector electrode 112 by the electrostatic field formed between the negative bias electrode 110 and the collector electrode 112. The result may be sent from the amplifier to a display / recorder 116 for viewing by a user. The ionized molecules 106 may receive electrons from the negative bias electrode 110, thereby reforming the molecules of interest 104.

[0029] The efficiency of the electron collection and ion recombination process depends on the electrode area and the electric field strength. The strength of the electric field may be affected by the use and structure of the PID sensor. For example, increasing the voltage, reducing the separation distance between the collector potential and the negative potential, and / or reducing the radius of curvature of the electrode pattern can increase the electric field strength. As described above, the use of TIA increases the system and background noise in addition to increasing the VOC signal. Therefore, increasing the strength of the electric field can allow the amplifier gain to be reduced, and thus an improvement in the signal-to-noise performance of the PID can be achieved.

[0030] In general, a PID may have components contained within a cylindrical housing, as illustrated in FIG2a for a prior art PID 200. More specifically, the cylindrical housing may contain a sensor body 202 with a cover 204, wherein the sensor body and cover contain a gas discharge lamp 206 (with a UV light source), a sensor 208, a gasket 210, a filter cloth 212, and a filter 214. As illustrated in FIG2a, these components may be stacked on top of each other, and the gas discharge lamp 206 and the sensor 208 may be placed adjacent to each other.

[0031] As briefly mentioned above, the sensor can include two or more electrodes, such as but not limited to a negative bias electrode, a collector electrode, and a ground electrode. Electrodes 216, 218, 220 can be approximately circular and can be positioned in a line with each other, as illustrated in FIG2b. In some embodiments, electrode 216 can be a negative bias electrode, electrode 218 can be a ground electrode, and electrode 220 can be a collector electrode. Although the details of the PID in FIG2a and the PID sensor in FIG2b are prior art, their components and layout can be consistent with the PID and sensor described herein. More specifically, as Figure 3-Figure 4 and Figure 7-Figure 8 As illustrated, similar to the PID sensor 208 from FIG. 2 b , the ground electrode 340 / 440 on the PID sensor 300 / 400 may be positioned between the negative bias electrode 320 / 420 and the collector electrode 330 / 430 .

[0032] As illustrated in Figures 2a-2b, the prior art electrodes 216, 218 and 220 are approximately circular. Since the voltage difference between the negative bias electrode and the collector can typically be tens or hundreds of volts, a third electrode, namely a ground electrode, can be used to block surface conduction current that may occur between the negative bias electrode and the collector. The collector and the ground electrode can each include a corresponding feedthrough pin that is electrically connected. Materials commonly used in PIDs include gold-plated features and tin-containing solder. The solder can be placed over the feedthrough pins and can further cover portions of the internal traces so that the appearance of each electrode is the appearance of an internal trace with solder on top.

[0033] As mentioned above, the improvements in the present disclosure are related to the structure and geometry of the PID sensor and its electrode pattern, which is designed to concentrate the electric field to the area of ​​the ionized molecules of interest to increase gain and improve linearity. Two embodiments of the PID sensor are described herein, both of which achieve the above-mentioned objects. Both include at least three electrodes, each electrode having a feedthrough pin, and each electrode having at least a first side located on the top or bottom of the sensor board and a second side located on the other of the top or bottom of the sensor board. More specifically, at least three electrodes can be collectors and ground electrodes and negative bias electrodes positioned adjacent to each other. The electrodes can be approximately circular, and the feedthrough pins of each electrode can be approximately centered. The feedthrough pins can include materials such as bronze, brass, copper, beryllium copper, stainless steel, etc., which can be plated with nickel, gold, silver, platinum, tin-lead and tin-silver. Each feedthrough pin can be soldered in place, and the solder can surround the feedthrough pin. Connected to the electrodes can be a conductive pattern. These patterns can be located on the top and / or bottom surface of the sensor plate and can help focus the electric field to the area of ​​ionized molecules of interest.

[0034] Example 1

[0035] A first PID sensor embodiment 300 is shown in Figure 3-Figure 6 , and includes a plate 302 having conductive patterns on a top surface 304 and a bottom surface 306, wherein a negative potential pattern 318 is located on one of the top surface 304 or the bottom surface 306, a collector pattern 328 is located on the other of the top surface 304 or the bottom surface 306, and the two patterns are offset relative to each other, as shown in FIG. Figure 3-Figure 4 As shown in the figure. Figure 5 As illustrated, the plate 302 may include at least one opening 316 in order to allow ultraviolet (UV) light from a gas discharge lamp to pass through and produce ionized molecules and electrons. Figure 6 The diagram shows the concentrated electric field generated by the conductive pattern on the sensor plate.

[0036] Negative potential pattern

[0037] Typically, negative potential pattern 318 may be located on top surface 304 of plate 302 (eg, Figure 3 ), may have an approximately rectangular outer perimeter, and may be connected to a negative bias electrode 320 positioned at one of the four corners of the top surface 304 of the sensor plate 302 (eg, the lower right corner, as shown). Figure 3 The negative potential pattern 318 may include metals such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel.

[0038] The negative potential pattern 318 may be positioned along at least a portion of at least three of the four edges of the sensor 300 without contacting the at least portion, such as Figure 3 More specifically, the negative potential pattern 318 may be provided along the entire first edge of the sensor 300 (eg, Figure 3 The negative potential pattern 318 is positioned such that the length of the first edge of the negative potential pattern 318 may be substantially the same as the length of the upper edge 308 of the sensor plate 302. Further, the negative potential pattern 318 may be disposed along a portion of the second edge and the third edge of the PID sensor 300 (e.g., Figure 3 The first edge of the sensor 300 may be positioned between the second edge and the third edge of the sensor 300 so that the first end of the first edge is connected to one end of the second edge and the second end of the first edge is connected to one end of the third edge. The length of each of the second negative potential pattern edge and the third negative potential pattern edge may be half to three quarters of the length of the sensor plate side edges 312, 314.

[0039] In some embodiments, the inner portion 324 of the negative potential pattern 318 can be at least a first distance from each edge of the at least one opening 316. More specifically, the negative potential pattern 318 can include a circular void 326 located in its interior (e.g., its center), and the circular void 326 can surround the at least one opening 316. In some cases, the circular void 326 can simply be an opening in the negative potential pattern 318. Thus, the void 326 can be open to the hydrophobic material of the plate 302. In other cases, the circular void 326 can include a hydrophobic material such that the void 326 is an additional layer on top of the plate 302. The hydrophobic material can be polytetrafluoroethylene.

[0040] As described above, the outer perimeter of the negative potential pattern 318 may be approximately rectangular. Therefore, the overall appearance of the negative potential pattern 318 may be a rectangular appearance with a circular void 326 located in the center thereof. Figure 3 As shown, the rectangular perimeter may not be uniform. More specifically, at least one corner of the perimeter may be missing. As mentioned herein, the negative potential pattern 318 and the collector pattern 328 may be offset from each other. Therefore, the absence of the negative potential pattern 318 in one corner may be aligned with a portion of the collector pattern 328 on the bottom surface 306 of the plate 302.

[0041] In embodiments where at least one opening 316 is a plurality of openings, the plurality of openings may form an approximately circular shape, such as Figure 3-Figure 4As shown. In some cases, multiple openings 316 can form an approximately circular outline and can continue within the approximately circular outline so that it fills the space therein. As mentioned above, the negative potential pattern 318 can include a gap 326. In an embodiment in which there is a gap 326, the outer edge of the circular gap 326 can be equidistant from the approximate outer periphery of the circular outline of the multiple openings 316, thereby minimizing the overlap of the negative potential pattern 318 with the collector pattern 328. Therefore, the only portions of the two patterns that can overlap are the remaining corner portions of the negative potential pattern 318 (i.e., the metal material bands retained between the gaps 326 and the non-existent corners) and the portion of the collector pattern 328 that transitions from the core pattern 334 to the connecting portion pattern 336 (described in more detail below).

[0042] Collector pattern

[0043] Typically, the collector pattern 328 may be located on the bottom surface 306 of the board 302 (eg, Figure 4 ), can have a teardrop shape, and can be connected to a positive collector 330 positioned at one of the four corners of the bottom surface 306 of the sensor board 302 (eg, the lower right corner, as shown). Figure 4 Similar to the negative potential pattern 318, the collector pattern 328 may include a metal such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel.

[0044] As mentioned above, the collector pattern 328 can be offset relative to the negative potential pattern 318. More specifically, the collector pattern 328 can substantially fill the area surrounding the opening 316, while the negative potential pattern 318 includes a void 326 in a corresponding space on the opposite side (e.g., top 304) of the plate 302. Thus, the area of ​​the collector pattern 328 surrounding the opening 316 can be similar to or smaller than the space between the edges of the opening 316 and the presence of a material portion of the negative potential pattern 318.

[0045] In some embodiments, the collector pattern 328 may have an approximately teardrop shape including a core pattern 334 and a connection pattern 336. The core pattern 334 may be an approximately circular pattern surrounding at least one opening 316, and the connection pattern 336 may be an elliptical extension connecting the core pattern 334 to the positive collector 330, as shown in FIG. Figure 4 In some cases, the core pattern 334 and the connecting portion pattern 336 may comprise two separate pieces of the same or different materials. In other cases, as illustrated herein, the core pattern 334 and the connecting portion pattern 336 may be formed from the same piece of material.

[0046] The core pattern 334 can have a first diameter on at least three quarters of its side, such that the distance from the center of the core pattern 334 outward to the outer periphery is the same or similar along at least three quarters of its side / edge. The diameter of the remaining portion of the core pattern 334 can vary to accommodate the attachment / transition of the connector pattern 336. As illustrated herein, the core pattern 334 can extend beyond the outer edge of at least one opening 316 so that it comprises an uninterrupted outer circumferential continuous surface.

[0047] In order to enable the collector pattern 328 to be offset relative to the negative potential pattern 318, the outer edge of the core pattern 334 (i.e., the portion of the core pattern 334 that is an outer circumferential continuous surface) may be closer to the center of the at least one opening 316 than the inner portion 324 of the negative potential pattern 318. More specifically, as mentioned above, the negative potential pattern 318 may include a circular void 326. The outermost portion of the circular void 326 may be a shared boundary with the inner portion 324 of the negative potential pattern 318. The core pattern 334 of the collector pattern 328 may fit within the circular void 326, a minority portion of the connection portion pattern 336 of the collector pattern 328 may overlap with the material portion of the negative potential pattern 318, and a majority of the connection portion pattern 336 of the collector pattern 328 may be separated between the circular void 326 and the outside of the outermost portion of the negative potential pattern 318.

[0048] In some embodiments, at least one opening 316 may be a plurality of openings forming an approximately circular shape. Such a circular configuration of the plurality of openings 316 may be positioned within the circular void 326. Therefore, in the case where the collector pattern 328 deviates from the negative potential pattern 318, the core pattern 334 of the collector pattern 328 may substantially fill the area surrounding the plurality of circular openings 316, and may have a diameter smaller than the diameter of the circular void 326.

[0049] Ground potential conductive pattern

[0050] Generally, the ground potential conductive pattern 338 may be a conductive pattern maintained at an electrical ground potential and may be positioned on the top surface 304 of the board 302 (eg, Figure 3 ), may be an approximately angular line, and may be connected to a ground electrode 340 positioned between the collector electrode 330 and the negative bias electrode 320 on the sensor board 302 (eg, the lower middle portion, such as Figure 3 The ground potential conductive pattern 338 may include a metal such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel.

[0051] Although the negative potential pattern 318 and the collector pattern 328 of the PID sensor 300 are shaped corresponding to and configured for the at least one opening 316, the ground potential conductive pattern 338 may be a simple angle line approximately at an obtuse angle. Figure 3 As illustrated, the negative potential pattern 318 may be positioned on the same surface as the negative potential pattern 318 (e.g., the top surface 304), and may be interposed between the negative potential pattern 318 and the collector 330 and the feed-through pin 332 to minimize the surface conduction effect. More specifically, the ground potential conductive pattern 338 may have a first linear portion / segment extending at an angle (e.g., an angle between 30 degrees and 60 degrees, such as 45 degrees) and a second linear portion / segment extending parallel to two opposite edges (e.g., the upper edge 308 and the lower edge 310) of the board 302. The first end of the ground potential conductive pattern 338 may be connected to the ground electrode 340, and the second end of the ground potential conductive pattern 338 may end near the side edge 312 of the board 302. The second end may be closer to the side edge 302 than the collector 330.

[0052] Feedthrough pin and pattern positioning / location

[0053] Similar to the prior art sensor illustrated in FIG. 2a-2b, each of the electrodes (negative bias electrode 320, positive collector electrode 330, and ground electrode 340) may have feedthrough pins 322, 332, 342. These feedthrough pins 322, 332, 342 may be electrically connected to their corresponding patterns 318, 328, 338. In other words, the negative bias electrode 320 may be electrically connected to the negative potential pattern 318, the positive collector electrode 332 may be electrically connected to the collector pattern 328, and the ground electrode 340 may be electrically connected to the ground potential conductive pattern 338.

[0054] As briefly mentioned above, patterns 318, 328, 338 may be located on similar or opposing surfaces of board 302. In one embodiment, negative potential pattern 318 and ground potential conductive pattern 338 may both be located on the same surface of board 302 (e.g., top surface 304, e.g., Figure 3-Figure 4 As illustrated), and the collector pattern 328 may be positioned on an opposite surface of the board 302 (eg, the bottom surface 306).

[0055] However, this arrangement is not required. In other embodiments, the electron collection pattern 328 and the ground pattern 338 can be located on the same surface (e.g., top 304), and the negative potential pattern 318 can be located on the opposite surface (e.g., bottom 306) of the plate 302. And in some embodiments, all three patterns 318, 328, 338 can be located on the same side of the plate 302 (e.g., top 304 or bottom 306).

[0056] In addition to the relative positions of the patterns 318, 328, 338 to each other, the placement of the patterns 318, 328, 338 relative to other patterns or feedthrough pins may also be specified. Figure 3 As illustrated and as mentioned above, the ground potential conductive pattern 338 can be inserted between the negative potential pattern 318 and the collector 330 and the feedthrough pin 332. However, as with the position of the patterns, their positions relative to each other may vary. Thus, in some embodiments, the ground potential conductive pattern 338 can be inserted between the collector pattern 328 and the negative bias electrode 320 and the feedthrough pin 322 connected to the negative potential pattern 318. Further, in some embodiments, the ground potential conductive pattern 338 can include two patterns, such that one pattern can exist on opposite sides of the board 302 (e.g., top 304 and bottom 306). Thus, in such an embodiment, the ground potential conductive pattern 338 can be inserted between (1) the negative potential pattern 318 and the collector 330 and the feedthrough pin 332, and (2) the collector pattern 328 and the negative bias electrode 320 and the feedthrough pin 322.

[0057] As mentioned above, the plate 302 may include at least one opening 316 and may include an electrically insulating substrate (e.g., polytetrafluoroethylene). The at least one opening 316 may be a single opening, or it may be a plurality of openings, such as Figure 3-Figure 4 As mentioned above, in embodiments with multiple openings, the openings can be approximately circular, can collectively take the shape of a circle, and can fill a circle. Thus, the multiple openings can be in the form of a circle containing an open circle. In embodiments with a single opening, the single opening can have a diameter similar to the diameter of the embodiment with multiple openings.

[0058] PID sensor board

[0059] In general, the PID sensor board 302 may be rectangular, having a top surface 304, a bottom surface 306, an upper edge 308, a lower edge 310, and two side edges 312 and 314. The top surface 304 and the bottom surface 306 may be portions of the board 302 on which negative potential patterns 318, collector electrodes 330, and ground potential conductive patterns 338 may be deposited. Feedthrough pins 322, 332, 342 may be positioned between the top surface 304 and the bottom surface 306 and near the lower edge 310. Depending on the type of feedthrough pins and electrodes (i.e., negative bias, positive, or ground), the feedthrough pins and electrodes may be closer to one side edge 312 or 314 than the other. Alternatively, it may be centered between the two side edges 312 and 314.

[0060] In contrast to prior art sensors where the board includes two material layers and patterns are deposited on the top, bottom, and in the middle, the board 302 of the present disclosure can be limited to a single hydrophobic layer with patterns on only the outer surface. More specifically, as described above, the negative potential pattern 318 can be deposited on the top surface 304, the ground potential conductive pattern 338 can be deposited on the top surface 304, and the collector pattern 328 can be deposited on the bottom surface 306. Other pattern arrangements on the top surface 304 and / or the bottom surface 306 are described above.

[0061] Although embodiments of the PID sensor 300 may include combinations of the features described above, the embodiments themselves may vary while still improving signal-to-noise performance and maximizing the gaps and distances between all electrodes so that they have a minimum shared contact area and allow for a more accurate and sensitive detector capable of use in more extreme (i.e., wet) environments.

[0062] For example, an embodiment of the PID sensor 300 may include: a board 302 including an electrically insulating substrate, a plurality of circular openings 316 for allowing UV light to pass through, a negative potential pattern 318 located on a top surface 304 of the board 302, a collector pattern 328 located on a bottom surface 306 of the board 302, and a ground potential conductive pattern 338 located on the top surface 304 of the board 302. Multiple circular openings 316 can form an approximate circle, the negative potential pattern 318 can include a circular gap 326 located at the center thereof, the circular gap 326 can surround the multiple circular openings 316, the circular gap 326 of the negative potential pattern 318 can include a hydrophobic material, the negative potential pattern 318 can be at least a first distance from each edge of the multiple circular openings 316, the collector pattern 328 can include a core pattern 334 and a connecting portion pattern 336, the core pattern 334 of the collector pattern 328 can roughly fill the area around the multiple circular openings 316, the connecting portion pattern 336 can connect the core pattern 334 to the collector feed-through pin 332, the diameter of the core pattern 334 of the collector pattern 328 can be smaller than the diameter of the circular gap 326, and the ground potential conductive pattern 338 can be inserted between the negative potential pattern 318 and the collector feed-through pin 332.

[0063] In another example, an embodiment of the PID sensor 300 may include a board 302 including an electrically insulating substrate, at least one opening 316 for passing UV light, a negative potential pattern 318 located on a top surface 304 of the board 302, and a collector pattern 328 located on a bottom surface 306 of the board 302. Similar to the above, the negative potential pattern 318 may include a void 326 located in the center thereof, and the void 326 may surround the at least one opening 316. Additionally, the negative potential pattern 318 and the collector pattern 328 may be offset relative to each other, the negative potential pattern 318 may be positioned along at least a portion of at least three of the four edges of the sensor 300 without contacting the at least portion, the negative potential pattern 318 may be positioned along the entire first edge 308 of the sensor 300, the negative potential pattern 318 may be positioned along a portion of the second edge 312 and the third edge 314 of the sensor 300, and the first edge 308 of the sensor 300 may be located between the second edge 312 and the third edge 314 of the sensor 300.

[0064] In use, a photoionization detector with an improved geometry and architecture for sensor electrodes can be used by activating a gas discharge lamp and reading the output of an amplifier. The gas discharge lamp can have a UV light source and can ionize molecules of interest to produce ionized molecules and electrons. The ionized molecules can be collected by a negative bias electrode 320 on the sensor 300, and the electrons can be collected by a collector 330 on the sensor 300. In some embodiments, the collector 330 can be further connected to an amplifier. The sensor 300 can include a plurality of conductive patterns located on a top surface 304 and a bottom surface 306 of an electrically insulating board 302. A negative potential pattern 318 can be located on one of the top surface 304 or the bottom surface 306 of the board 302, and can have a gap 326 that causes an inner edge 324 of the negative potential pattern 318 to be at least a first distance away from an opening 316 in the board 302. The collector pattern 328 can be located on the surface of the board 302 opposite the negative potential pattern 318 and can both surround the opening 316 in the board 302 and fill a similarly sized area to the gap 326 of the negative potential pattern 318 so that the two patterns are offset relative to each other. The ground potential conductive pattern 338 on the sensor 300 can be positioned between the negative potential pattern 318 and the collector 330 and the feedthrough pin 332.

[0065] Example 2

[0066] A second PID sensor embodiment 400 is shown in Figure 7-10 , and includes a plate 402 having at least one opening 416 and conductive patterns 418, 428, 438 located on a top surface 404 and a bottom surface 406, wherein a negative potential pattern 418 is located on one of the top surface 404 or the bottom surface 406, a collector pattern 428 is located on the other of the top surface 404 or the bottom surface 406, and the collector pattern 428 includes a wire 436 suspended across the at least one opening 416, as shown in FIG. Figure 7-Figure 8 As shown in the figure. Fig. 9 As illustrated, at least one opening 416 allows ultraviolet (UV) light from a gas discharge lamp to pass through the plate 402, interact with the ionized gas proximate the wire 436, and produce ionized molecules and electrons. Fig.10 The diagram shows the concentrated electric field generated by the conductive patterns 418, 428, 438 (e.g., the polarization plate 426 of the negative potential pattern 418 and the wire 436 of the collector pattern 428) on the sensor board 402. In general, Embodiment 2 (PID sensor 400) reduces the surface on which water can be adsorbed, which is beneficial because the adsorbed water can cause leakage current between the polarization plate 426 of the negative potential pattern 418 and the wire 436 of the collector pattern 428.

[0067] Negative potential pattern

[0068] Typically, the negative potential pattern 418 may be located on, but not limited to, the top surface 404 of the board 402 (eg, Figure 7 402 ), and may include a plurality of linear sections / segments 424, a polarization plate 426, a negative bias electrode 420, and a feedthrough pin 422. In some embodiments, the linear section / segment 424 may be connected between the polarization plate 426 and the negative bias electrode 420 and the feedthrough pin 422. The negative bias electrode 420 and the feedthrough pin 422 may be positioned at one of the four corners of the top surface 404 of the sensor board 402 (e.g., the lower right portion or corner of the board 402, such as Figure 7 The negative potential pattern 418 may include metals such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel.

[0069] The plurality of linear portions / segments 424 of the negative potential pattern 418 may include three portions (although the number of portions / segments may be more or less). As mentioned above, the negative potential pattern 418 may be located on the top surface 404 of the plate 402. However, in other embodiments, the negative potential pattern 418 may be located on the bottom surface 406 of the plate 402. The first linear portion 424a of the plurality of linear portions / segments 424 may be parallel to two opposite edges of the plate 402 (e.g., side edges 412 and 414). The second linear portion 424b may be at an angle (e.g., between 30 and 60 degrees, such as 45 degrees). The third linear portion 424c may be parallel to two opposite edges of the plate 402 (e.g., side edges 412 and 414). Therefore, the first segment 424a and the third segment 424c may be parallel to each other. Additionally, the third section 424c may be closer to the middle of the plate 402, and therefore further from the side edge 414 than the first section 424a, as shown in FIG. Figure 7 As shown.

[0070] A first end of the negative potential pattern 418 may be connected to the negative bias feedthrough pin 422 and the electrode 420. A second end of the negative potential pattern 418 may be connected to the polarizing plate 426. The second end may be connected near the end of the polarizing plate 426 closest to the negative bias electrode 420, such as Figure 7As shown. Therefore, even though the third segment 424c (and the second end) may be more centered than the first segment 424a (and the first end), the third segment 424c and the second end may still be closer to the side edge 414 relative to the side edge 412. Alternatively, the second end may be connected closer to the center portion of the polarization plate 426 or connected closer to the end of the polarization plate 426 farthest from the negative bias electrode 420 (i.e., closer to the side edge 412 relative to the side edge 414). In some cases, the negative potential pattern 418 may be a single linear or curved pattern (rather than multiple segments) with two ends, wherein the first end is connected to the negative bias electrode 420 and the feedthrough pin 422, and the second end is connected to the polarization plate 426.

[0071] In some cases, polarizing plate 426 may appear as an extension of linear portion / segment 424, such that the two components are a continuation of the same material. Figure 7 As shown, the polarizing plate can be wider than the linear portion / segment 424. More specifically, the width of the first segment 424a is defined herein as Figure 7 The width of the polarizing plate 426 is defined as the distance from left to right in the material, and the widths of the second segment 424b and the third segment 424c are shown as being the same as the width of the first segment 424a, although variations are possible. Figure 7 Thus, as shown, polarizing plate 426 is wider than linear portion / segment 424.

[0072] In some embodiments, and as Figure 7 As shown, polarizing plate 426 can be adjacent to and extend along the length of at least one opening 416. In some cases, opening 416 can be wider than polarizing plate 426, where the width of opening 416 is defined herein as Figure 7-Figure 8 The distance from the top to the bottom of the middle opening 416. Further, the polarizing plate 426 can be longer than the opening 416, wherein the length of the opening 416 and the polarizing plate 426 is defined herein as Figure 7-Figure 8 Thus, the end of the polarizing plate 426 may be closer to the two side edges 412 and 414 than the opening 416, although both the opening 416 and the polarizing plate 426 may be approximately centered between the two side edges 412, 414.

[0073] Collector pattern

[0074] Typically, collector pattern 428 may be located on top surface 404 and bottom surface 406 of board 402, such as Figure 7-Figure 8402, a positive collector 430, a feedthrough pin 432, and a wire opening 437. In some embodiments, the linear pattern 434 can be connected to the positive collector 430 and the feedthrough pin 432 on one end, and to the wire opening 437 on the opposite end. The negative bias electrode 420 and the feedthrough pin 422 can be positioned at one of the four corners of the bottom surface 406 of the sensor board 402 (e.g., the lower right portion or corner of the board 402, such as Figure 8 Similar to the negative potential pattern 418, the linear pattern 434 of the collector pattern 428 may include a metal such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel. The suspended wire 436 may include a metal such as, but not limited to, gold, copper, nickel, platinum, and stainless steel.

[0075] In some embodiments, the linear pattern 434 of the collector pattern 428 may be deposited on a first surface of the board 402, and the suspended wire 436 may be suspended above a second surface of the board 402. Figure 8 As illustrated, the linear pattern 434 may be deposited on the bottom surface 406 of the board 402, while the suspended conductive lines 436 may be suspended above the top surface 404 of the board 402. In some cases, this may be reversed, and the linear pattern 434 may be deposited on the top surface 404, while the suspended conductive lines 436 may be suspended above the bottom surface 406 of the board 402. In still other embodiments, the linear pattern 434 and the suspended conductive lines 436 may be located on the same surface (e.g., both located on the top 404 or both located on the bottom 406).

[0076] The linear pattern 434 may include a plurality of linear portions / segments that connect the collector 430 and the feedthrough pin 432 to a wire opening 437 that is also connected to a first end of a wire 436 (e.g., the wire 436 may be soldered in place in the opening 437). Thus, one end of the linear pattern 434 may be connected to the collector 430 and the feedthrough pin 432, and the opposite second end of the linear pattern 434 may be connected to the wire opening 437. As mentioned above, the linear pattern 434 may include a plurality of linear portions / segments. In some cases, the plurality of linear portions / segments of the linear pattern 434 may include four segments, although as with the linear portions / segments 424 of the negative potential pattern 418, there may be fewer or more than four segments in the linear pattern 434 of the collector pattern 428.

[0077] The linear pattern 434 may include a first short segment 434a parallel to the side edges 412 and 414 of the plate 402, a second relatively short angled segment 434b (e.g., between 30 and 60 degrees, such as an angle of 45 degrees), a third segment 434c perpendicular to the side edges 412 and 414 of the plate 402 and longer than the first two segments, and a fourth segment 434d as the longest segment and parallel to the side edges 412 and 414 of the plate 402. Thus, the first segment 434a and the fourth segment 434d may be parallel to each other, and the third segment 434c may be perpendicular to the first segment 434a and the fourth segment 434d. Additionally, the segments may gradually approach the side edge 412 or 414. More specifically, the first segment 434a may be the segment closest to the middle of the plate 402 and thus the farthest segment from the side edge 412 or 414, while the fourth segment 434d may be the segment closest to the side edges 412 and 414 and thus the farthest segment from the middle of the plate 402, as shown in FIG. Figure 8 As shown, the second section 434b and the third section 434c fall between the first section 434a and the fourth section 434d.

[0078] As mentioned above, the linear pattern 434 can be connected to the connection portion electrode 430 and the feed-through pin 432 at a first end, and connected to the wire opening 437 at the other end. More specifically, the first segment 434a can be connected to the collector 430 and the feed-through pin 432 at one end, and connected to the second segment 434b at the other end. The fourth segment 434d can be connected to the wire opening 437 at one end, and connected to the third segment 434c at the other end. The second segment 434b and the third segment 434c can be connected to each other at their other ends. Although the linear pattern 434 of the collector pattern 428 is described above as being composed of several segments / portions, it does not need to be several segments, but can be a single linear or curved pattern (rather than multiple segments) with two ends, wherein the first end is connected to the connection portion electrode 430 and the feed-through pin 432, and the second end is connected to the wire opening 437.

[0079] Although one of the wire openings 437 can be connected to the linear pattern 434, it can also be connected to the wire 436. More specifically, the suspended wire 436 can include a single thin wire 436 (e.g., between 0.01 inches and 0.05 inches), which is connected to a pair of openings 437 embedded in the PID sensor board 402 at each end. This connection can be performed by, for example, welding, so that the wire 436 is kept in place. Although the wire 436 is described as a single wire in this article, the wire 436 is considered to also include a situation in which it includes multiple wires in this article. Multiple wires can be combined (i.e., twisted, braided, etc.) so that it produces a larger wire. In other cases, it can be attached to the wire opening 437 separately and adjacent to each other, but not intertwined, and therefore separated from each other. Alternatively, multiple wires can be connected at different positions on the board 402 so that there is a separate wire pin for each wire and there is space between each wire.

[0080] Conductor 436 may be parallel to upper edge 408 and lower edge 410 of board 402 (and therefore, perpendicular to side edges 412 and 414), and may span a majority of the width of board 402, such as Figure 7 As shown. Wire opening 437 can function as a feedthrough hole that enables wire 436 to be embedded in board 402 and then soldered in place. More specifically, wire opening 437 can be embedded in the upper half of board 402 (i.e., on top surface 404, and both openings are on the opposite half of top surface 404 compared to the electrodes / feedthrough pins of negative potential pattern 418, collector pattern 428, and ground potential conductive pattern 438) and close to / along side edges 412 and 414 (e.g., closer to side edges 412 and 414 than any of negative bias electrode 420, collector 430, or ground electrode 440). Although one of wire openings 437 can be connected to both linear pattern 434 and wire 436, thereby connecting wire 436 to linear pattern 434, another of wire openings 437 can be connected only to wire 436. As mentioned above, the wire 436 may be suspended above the surface of the board 402 and positioned above the opening 416. Further, only the wire 436 (and not the wire opening 437) may be positioned near the opening 416. As described in further detail below, the wire opening 437 may be separated from the opening by at least a ground potential conductive pattern 438.

[0081] Ground potential conductive pattern

[0082] Generally, the ground potential conductive pattern 438 may be a conductive pattern maintained at an electrical ground potential and may be positioned on the top 404 and bottom surface 406 of the board 402, such as Figure 7-Figure 8As shown, the sensor board 402 may include a plurality of linear sections / segments 444, 446, a UV blocking electrode 446b, a ground electrode 440, and a feedthrough pin 442. In some embodiments, the linear sections / segments 444, 446 may be connected to the ground electrode 440 and the feedthrough pin 442. The ground electrode 440 and the feedthrough pin 442 may be positioned between the collector electrode 430 and the negative bias electrode 420 on the sensor board 402 (e.g., the middle lower portion, such as Figure 7-Figure 8 The ground potential conductive pattern 438 may include a metal such as, but not limited to, copper, nickel, chromium, titanium, gold, silver, platinum, and stainless steel.

[0083] The multiple linear portions / segments 424 of the negative potential pattern 418 can include three portions (although the number of portions / segments can be more or less). The first linear portion 424a of the multiple linear portions / segments 424 can be parallel to two opposing edges of the plate 402 (e.g., the side edges 412 and 414). The second linear portion 424b can be at a certain angle (e.g., between 30 degrees and 60 degrees, such as 45 degrees). The third linear portion 424c can be parallel to two opposing edges of the plate 402 (e.g., the side edges 412 and 414). Therefore, the first segment 424a and the third segment 424c can be parallel to each other. Additionally, the third segment 424c can be closer to the middle of the plate 402, and therefore farther from the side edge 414 than the first segment 424a, as shown in FIG. Figure 7 As shown.

[0084] As mentioned above, the ground potential conductive pattern 438 may include a first portion 444 deposited on a first surface (e.g., top surface 404) of the board 402 and a second portion 446 deposited on an opposite surface (e.g., bottom surface 406) of the board 402. Alternatively, the first portion 444 may be deposited on the bottom surface 406 of the board 402, while the second portion 446 may be deposited on the top surface 404 of the board 402. In yet another embodiment, both the first portion 444 and the second portion 446 may be deposited on the same surface of the board 402 (e.g., both are deposited on the top surface 404 or both are deposited on the bottom surface 406).

[0085] The first portion 444 may be interposed between the wire opening 437 and the remaining pattern and opening 416 of the top surface 404 of the plate 402. More specifically, the first end of the ground potential conductive pattern 438 may be connected to the ground electrode 440, which may be positioned between the collector 430 and the negative bias electrode 420. The ground potential conductive pattern 438 may then be wound around at least one opening 416 in the plate 402, the polarizing plate 426, and a portion of the negative potential pattern 418, so that the wire opening 437 is positioned on the opposite side (e.g., the outside) of the ground potential conductive pattern 438 relative to these other components (e.g., may be on the inside). The second end of the ground potential conductive pattern 438 may terminate near the side edge. For example, the ground potential conductive pattern 438 may be near the side edge 414 closest to the negative potential pattern 418, thereby surrounding the polarizing plate 426 and a portion of the linear portion / segment 424 of the negative potential pattern 418, and preventing the ground potential conductive pattern 438 from crossing with the negative potential pattern 418.

[0086] Like the negative potential pattern 418 and the collector pattern 428, the first portion 444 of the ground potential conductive pattern 438 may include a plurality of linear portions / segments. Figure 7 , there may be fewer or more than six segments in the first portion 444 of the ground potential conductive pattern 438. For example, the first portion 444 may be a single meander pattern (rather than multiple segments) having two ends, wherein the first end is connected to the ground electrode 440 and the feed-through pin 442, and the second end terminates near the side edge 414.

[0087] In an embodiment of a first portion 444 having multiple segments, a first segment 444a may be connected to the ground electrode 440 and the feed-through pin 442 at a first end, and may be connected to a second segment 444b at a second end. The first segment 444a may be substantially parallel to the side edges 412 and 414, and may be substantially centered between the side edges 412 and 414.

[0088] The second segment 444b can be at an angle (e.g., between 30 and 60 degrees, such as 45 degrees) to the negative bias electrode 420 and can be connected to the third segment 444c. In some embodiments, the first segment and the second segment can be combined into a single segment that is connected to the ground electrode 440 and the feed-through pin 442 on a first end and to the next segment on a second end. In those embodiments, the combined first and second segments can be at an angle (e.g., between 30 and 60 degrees, such as 45 degrees) to the negative bias electrode 420.

[0089] The third segment 444c may be connected to the second segment 444b (or, as mentioned above, the combined first and second segments) on a first end, may be parallel to the side edges 412 and 414 of the plate 402, may span from a position closer to the lower edge 410 of the plate 402 relative to the polarizing plate 426 to a position closer to the upper edge 408 relative to the opening 416 in the plate 402, and may be connected to the fourth segment 444d on a second end. Thus, the third segment 444c may be completely interposed between the side edge 412 or 414 and the polarizing plate 426 and the opening 416. Thus, the opening 416 and the polarizing plate 426 may be positioned inside the third segment 444c (i.e., closer to the middle of the plate 402), while the wire opening 437 is positioned outside the third segment 444c (i.e., closer to the edge 412 or 414 of the plate 402).

[0090] The fourth section 444d can be connected to the third section 444c on the first end and to the fifth section 444e on the second end. The fourth section 444d can be parallel to the upper edge 408 and the lower edge 410 of the plate 402. The fourth section 444d can be longer than both the polarizing plate 426 and the opening 416 (as measured along the axis from the side edge 412 to the side edge 414). The fourth section 444d can also be shorter than the length of the suspended wire 436 of the collector pattern 428 (as measured along the axis from the side edge 412 to the side edge 414). The fourth section 444d can be positioned and deposited between the opening 416 and the upper edge 408 of the plate 402. Therefore, the opening 416 can be positioned between the polarizing plate 426 and the fourth section 444d, and all three components can be parallel to each other and to the upper edge 408 and the lower edge 410 of the plate 402.

[0091] The fifth segment 444e may be similar to the third segment 444c on the opposite end of the polarizing plate 426 and the opening 416, such that it is parallel to the side edges 412 and 414 of the plate 402, has a first upper end closer to the upper edge 408 than the opening 416 in the plate 402, and a second lower end closer to the lower edge 410 of the plate 402 than the polarizing plate 426. As mentioned above, the fifth segment 444e may be connected to one end of the fourth segment 444d at its upper end. The fifth segment 444e may be connected to the sixth segment 444f at its lower end. As with the third segment 444c, the opening 416 and the polarizing plate 426 may be located inside the fifth segment 444e (i.e., closer to the middle of the plate 402), while the wire opening 437 may be located outside the fifth segment 444e (i.e., closer to the edge 412 or 414 of the plate 402). The first section 444a, the third section 444c and the fifth section 444e may be parallel to each other. Figure 7As illustrated, the first segment 444a and the fifth segment 444e may be closer to the side edges 412 and 414 than the third segment 444c.

[0092] The last sixth segment 444f may be parallel to the upper edge 408 and the lower edge 410 of the plate 402, may be connected to the fifth segment 444e on a first end, and may terminate on a second end near the side edge 412 or 414 of the plate 402. The termination point of the sixth segment 444f may be closer to the side edge 412 or 414 than the wire opening 437. The sixth segment 444f may also be parallel to the fourth segment 444d, the opening 416, the polarizing plate 426, and the wire 436, and the opening 416, the polarizing plate 426, and the wire 436 may be positioned between the fourth segment 444d and the sixth segment 444f.

[0093] like Figure 7 As shown, the negative potential pattern 418 can be completely separated from the wire opening 437 by the ground potential conductive pattern 438. Further, the negative potential pattern 418 can be blocked by the polarizing plate 426 without being affected by the wire 436 itself, and the polarizing plate is closer to the lower edge 410 (and the negative potential pattern 418) than the opening 416 on which the wire 436 is suspended. Additionally, this first portion 444 of the ground potential conductive pattern 438 can separate the collector 430 from the negative potential pattern 418, which helps to minimize the surface conduction effect. Based on the material of the plate 402 (e.g., a hydrophilic material such as polytetrafluoroethylene), the surface conduction effect can be further reduced.

[0094] As mentioned above, the ground potential conductive pattern 438 may have a second portion 446 positioned on an opposite surface (eg, bottom surface 406) of the PID sensor board 402. The second portion 446 of the ground potential conductive pattern 438 may also include a plurality of linear portions / segments. Figure 8 , there may be fewer or more than five segments in the second portion 446 of the ground potential conductive pattern 438. For example, the second portion 446 may be a single meandering pattern (rather than multiple segments) having two ends, wherein the first end is connected to the ground electrode 440 and the feed-through pin 442, and the second end terminates on a portion of the pattern.

[0095] In an embodiment of the second portion 446 having multiple segments, the first segment 446a can be connected to the ground electrode 440 at a first end and connected to the second segment 446b at a second end (e.g., at a middle portion of the second segment 446b). The first segment 446a can be parallel to the side edges 412 and 414 of the plate 402 and can be approximately centered between the side edges 412 and 414.

[0096] The second segment 446b can be perpendicular to the first segment 446a, can be on the upper half of the plate 402, can be centered between the side edges 412 and 414, and can be connected to the third segment 446c on a first end and to the fourth segment 446d on a second end. In some embodiments, the second segment 446b can be a UV blocking electrode. Further, the second segment 446b can be longer than the opening 416 in the plate 402, such that its first end is closer to one side 412 or 414 of the plate 402 than the opening 416, and its second end is closer to the opposite side 412 or 414 of the plate 402 than the opening 416. However, as Figure 8 As shown, the second section 446b may not extend to the location of the wire opening 437; its end may terminate at a point just past the end of the opening 416. Figure 8 As illustrated, the second section 446 b may be the widest section of the second portion 446 .

[0097] The third segment 446c and the fourth segment 446d may be mirror images of each other, may both be parallel to the side edges 412 and 414 of the board 402, and may be connected at their first ends to the end of the second segment 446b and at their second ends to the end of the fifth segment 446e. The upper ends of the third segment 446c and the fourth segment 446d may terminate at a position closer to the upper edge 408 of the board 402 than the opening 416. Thus, the opening 416 may be positioned inside the third segment 446c (i.e., closer to the middle of the board 402), while the wire opening 437 may be positioned outside the third segment 446c (i.e., closer to the edge 412 or 414 of the board 402). Similarly, opening 416 may be positioned inside fourth segment 446d (ie, closer to the middle of plate 402 ), while wire opening 437 may be positioned outside fourth segment 446d (ie, closer to edge 412 or 414 of plate 402 ).

[0098] The fifth segment 446e can be similar to the second segment 446b in that it is parallel to the upper edge 408 and the lower edge 410 of the plate 402 and has a similar width as the second segment 446b. As mentioned above, the fifth segment 446e can be connected to the third segment 446c on a first end and to the fourth segment 446d on a second end.

[0099] Therefore, a portion of the second portion 446 of the ground potential conductive pattern 438 (i.e., the second segment 446b, the third segment 446c, the fourth segment 446d, and the fifth segment 446e) may surround the opening 416 in the form of a rectangular box, thereby being interposed between the opening 416 and the linear pattern 434 of the collector pattern 428, and between the opening 416 and the wire opening 437, and the first segment 446a may connect the box to the ground electrode 440 and the feed-through pin 442, which may be positioned between the collector 430 and the negative bias electrode 420. Although the second segment 446b may be a UV blocking electrode, the third segment 446c, the fourth segment 446d, and the fifth segment 446e may serve as an additional guard line surrounding at least one opening 416. This pattern 438 can align with and block UV light from passing through openings 416 and reaching negative potential pattern 418 to (1) prevent the generation of photoelectrons and (2) minimize or eliminate any spurious background signals due to photoelectrons.

[0100] In some embodiments, the first portion 444 of the ground potential conductive pattern 438 may be substantially aligned with the second portion 446 of the ground potential conductive pattern 438. More specifically, the third segment 444c, the fourth segment 444d, and the fifth segment 444e of the first portion 444 of the ground potential conductive pattern 438 may be substantially aligned with the third segment 446c, the fourth segment 446d, and the fifth segment 446e of the second portion 446 of the ground potential conductive pattern 438. Further, the polarizing plate 426 of the negative potential pattern 418 may be substantially aligned with the second segment 446b (i.e., the UV blocking electrode) of the second portion 446 of the ground potential conductive pattern 438.

[0101] Feedthrough pin and pattern positioning / location

[0102] Unless otherwise mentioned herein, the feedthrough pins in the PID sensor of embodiment 2400 share the same features as the PID sensor 300 of embodiment 1. For example, a feedthrough pin may be provided for each of the electrodes (negative bias electrode 420, positive collector electrode 430, and ground electrode 440), and these corresponding feedthrough pins 422, 432, 442 may be electrically connected to their corresponding patterns 418, 428, 438.

[0103] As briefly mentioned above, the patterns may be located on similar or opposite surfaces of the plate 402. In one embodiment, the first surface (e.g., top surface 404) of the plate 402 may include the negative potential pattern 418, the polarizing plate 426, the conductive line 436 portion of the collector pattern 428, and the first portion 444 of the ground potential conductive pattern 438, as shown in FIG. Figure 7As illustrated, the second surface (eg, bottom surface 406 ) of the board 402 may include the linear pattern 434 of the collector pattern 428 and the second portion 446 of the ground potential conductive pattern 438 , as illustrated in Table 8.

[0104] However, this arrangement is not required. In other embodiments, the wire 436 portion of the collector pattern 428 can be located on the same side as the linear pattern 434 of the collector pattern 428, or the ground potential conductive pattern 438 can be limited to a single surface (i.e., the top 404 or the bottom surface 406). And in some embodiments, all three patterns 418, 428, 438 can be located on the same side of the board 402 (e.g., the top 404 or the bottom 406).

[0105] As with the PID sensor 300 of Embodiment 1, in addition to the relative positions of the patterns of Embodiment 2, the placement of the patterns relative to other patterns or feedthrough pins may also be specified. Figure 6-Figure 7 As illustrated and as mentioned above, the ground potential conductive pattern 438 may be interposed between the two wire openings 437 and the negative potential pattern 418 on the top surface 404, between the negative potential pattern 418 and the collector 430 and feedthrough pin 432 on the top surface 404, between the collector 430 and feedthrough pin 432 and the negative bias electrode 420 and feedthrough pin 422 on the bottom surface 406, and between at least one opening 416 and the collector 430 and feedthrough pin 432 on the bottom surface 406. However, as with the location of the patterns, their locations relative to each other may vary.

[0106] PID sensor board

[0107] Typically, the PID sensor board 402 can be rectangular, having a top surface 404, a bottom surface 406, an upper edge 408, a lower edge 410, and two side edges 412 and 414. The top surface 404 and the bottom surface 406 can be portions of the board 402 on which negative potential patterns 418, collector electrodes 430, and ground potential conductive patterns 438 can be deposited. As mentioned above, the board 402 can include at least one opening 416 and can include an electrically insulating substrate (e.g., polytetrafluoroethylene). Feedthrough pins 422, 432, 442 can be positioned between the top surface 404 and the bottom surface 406 and near the lower edge 410, and can allow electrical connection to the pattern on the board 402. Depending on the type of feedthrough pins and electrodes (i.e., negative bias electrodes 420 / 422, positive electrodes 430 / 432, or ground electrodes 440 / 442), the feedthrough pins and electrodes can be closer to one side edge 412 or 414 than to another side edge. Alternatively, it may be centered between the two side edges 412 and 414 .

[0108] The at least one opening 416 of the PID sensor board 402 may be a single opening, such as Figure 7-Figure 8 As shown, or it can be a plurality of openings. The shape of a single opening 416 can be approximately oval, and can be generally parallel to the upper edge 408 and the lower edge 410 of the plate 402. The opening 416 can be centered between the two wire openings 437 (and correspondingly centered between the two side edges 412 and 414 of the plate 402) so that an equal number of openings 416 are positioned on either side of the wire 436. Thus, the opening 416 can be closer to the upper edge 408 of the plate 402 relative to the lower edge 410 of the plate 402. Further, the opening 416 can have a similar or smaller width than the polarizing plate 426. In embodiments where the opening 416 is a plurality of openings, the plurality of openings can continue to produce a generally integrally shaped elliptical opening. For example, each opening can be circular (or elliptical), and the combination of the openings can produce a larger ellipse, similar to Figure 3-Figure 4 How multiple circular openings in create a larger circle.

[0109] Fig. 9 and Fig.10 The diagram shows how the electric field is concentrated around the edge of the polarizing plate 426 of the wire 436 and the negative potential pattern 418. As shown, a high electric field is generated where UV light exists and where VOC gas is introduced. This solves the problems of high gain, linearity and time response of PID design. Due to the air gap of the large opening 416 and the long distance between the polarizing plate 426 and the components of the collector pattern 428 (i.e., the wire 436 and the wire opening 437), humidity sensitivity can also be reduced. As shown, the ground potential conductive pattern 438 can separate the collector pattern 428 (e.g., the wire 436) from the negative potential pattern 418 to minimize the surface conduction effect.

[0110] As with the PID sensor 300 of Example 1, the plate 402 of the PID sensor 400 may be limited to a single hydrophobic layer having a pattern only on the outer surface (or suspended above it in the case of the wire 436), rather than including two material layers in which electrode patterns are deposited on the top, bottom, and middle. More specifically, as described above, the negative potential pattern 418 may be deposited on the top surface 404, the ground potential conductive pattern 438 may be deposited on the top surface 404 and the bottom surface 406, and the collector pattern 428 may have a linear pattern 434 deposited on the bottom surface 406 and a suspended wire 436 located above the top surface 404. Other pattern arrangements on the top surface 404 and / or the bottom surface 406 are described above.

[0111] Therefore, the PID sensor 400 of Example 2 combines several features that improve its VOC gas detection function. The opening 416, which can be larger than the opening of the prior art, allows UV light to reach the VOC gas introduced above the detector and improves the time response. The polarizing plate 426 of the negative potential pattern 418 can be spaced near the wire 436 suspended above it. The combination of the wire 436, which can have a small diameter, and the sharp edge of the polarizing plate 426 can increase the electric field in its immediate vicinity. Also similar to the PID sensor 300 of Example 1, although the PID sensor 400 of Example 2 can include a combination of the above-mentioned features, the embodiment itself can be changed while still improving the signal-to-noise performance and maximizing the gap and distance between all electrodes so that it has a minimum shared contact area and allows a more accurate and sensitive detector that can be used in more extreme (i.e., humid) environments.

[0112] The various embodiments described above are provided by way of illustration only and should not be construed as limiting the appended claims. Those skilled in the art will readily appreciate that various modifications and changes may be made without departing from the true spirit and scope of the following claims based on the exemplary embodiments and applications illustrated and described herein.

Claims

1. A planar photoionization detector, characterized in that: The planar photoionization detector comprises: a gas discharge lamp that ionizes molecules of interest to produce ionized molecules and electrons; and A sensor comprising at least one plate comprising a top surface, a bottom surface, an electrically insulating substrate, and at least one opening for passing UV light; and a conductive pattern located on the top surface and the bottom surface, the conductive pattern including at least a negative potential pattern located on one of the top surface or the bottom surface; and a collector pattern located on the other of the top surface or the bottom surface, in The inner portion of the negative potential pattern is at least a first distance from each edge of the at least one opening, and The collector pattern substantially fills a region surrounding the opening such that the negative potential pattern and the collector pattern are offset relative to each other.

2. The planar photoionization detector according to claim 1, characterized in that: The conductive patterns further include at least one conductive pattern maintained at an electrical ground potential.

3. The planar photoionization detector according to claim 2, characterized in that: The planar photoionization detector further comprises a feedthrough pin electrically connected to the collector pattern, wherein The ground potential conductive pattern is located on the same board surface as the negative potential pattern, and The ground potential conductive pattern is interposed between the negative potential pattern and a collector feed-through pin.

4. The planar photoionization detector according to claim 3, characterized in that: The planar photoionization detector further includes a second ground potential conductive pattern located on a surface opposite to the ground potential conductive pattern, wherein the second ground potential conductive pattern is interposed between the collector pattern and a feed-through pin electrically connected to the negative potential pattern.

5. The planar photoionization detector according to claim 1, characterized in that: The at least one opening is a single opening.

6. The planar photoionization detector according to claim 1, characterized in that: The at least one opening includes a plurality of openings.

7. The planar photoionization detector according to claim 1, characterized in that: The electrically insulating substrate is polytetrafluoroethylene.

8. The planar photoionization detector according to claim 1, characterized in that: The plate is a single hydrophobic layer having the negative potential pattern deposited on the top surface, the ground potential conductive pattern deposited on the top surface, and the collector pattern deposited on the bottom surface.

9. The planar photoionization detector according to claim 1, characterized in that: The collector pattern includes a core pattern and a connection portion pattern, The core pattern is an approximately circular pattern surrounding the at least one opening, The core pattern has an uninterrupted outer circumferentially continuous surface, and The outer circumferential continuous surface of the core pattern is closer to a center of the at least one opening than the inner portion of the negative potential pattern.

10. The planar photoionization detector according to claim 1, characterized in that: The negative potential pattern is positioned along at least a portion of at least three edges of four edges of the sensor without contacting the at least portion.

11. The planar photoionization detector according to claim 10, characterized in that: The negative potential pattern is positioned along the entire first edge of the sensor.

12. The planar photoionization detector according to claim 11, characterized in that: The negative potential pattern is positioned along a portion of the second edge and the third edge of the sensor, and The first edge of the sensor is located between the second edge and the third edge of the sensor.

13. The planar photoionization detector according to claim 1, characterized in that: The negative potential pattern includes a circular void located at a center thereof, and the circular void surrounds the at least one opening.

14. The planar photoionization detector according to claim 13, characterized in that: The circular gaps of the negative potential pattern are open to the hydrophobic material of the plate.

15. The planar photoionization detector according to claim 14, characterized in that: The hydrophobic material is polytetrafluoroethylene.

16. The planar photoionization detector according to claim 13, characterized in that: The at least one opening is a plurality of openings, The plurality of openings form an approximately circular contour, and The plurality of openings continue within the approximately circular profile.

17. The planar photoionization detector according to claim 16, characterized in that: An outer edge of the circular void is equidistant from the approximately circular outline of the plurality of openings.

18. The planar photoionization detector according to claim 17, characterized in that: The collector pattern includes a core pattern and a connection portion pattern, The core pattern of the collector pattern substantially fills a region surrounding the plurality of circular openings, and The core pattern of the collector pattern has a diameter smaller than a diameter of the circular void.

19. A planar photoionization detector sensor, characterized in that: The planar photoionization detector sensor comprises a board having a top surface and a bottom surface and comprising an electrically insulating substrate, a plurality of circular openings for passing UV light therethrough, A negative potential pattern located on the top surface, a collector pattern located on the bottom surface, and a ground potential conductive pattern located on the top surface, in The plurality of circular openings form an approximate circle, The negative potential pattern comprises a circular void at its center, The circular gap surrounds the plurality of circular openings, The circular gaps of the negative potential pattern contain a hydrophobic material, The negative potential pattern is at least a first distance away from each edge of the plurality of circular openings, The collector pattern includes a core and a connection portion, the core of the collector pattern substantially fills an area surrounding the plurality of circular openings, The connection portion connects the core to the collector feed-through pin, The core of the collector pattern has a diameter smaller than a diameter of the circular void, and The ground potential conductive pattern is interposed between the negative potential pattern and a collector feed-through pin.

20. A planar photoionization detector sensor, characterized in that: The planar photoionization detector sensor comprises a board having a top surface and a bottom surface and comprising an electrically insulating substrate, at least one opening for passing UV light therethrough, a negative potential pattern on the top surface, and a collector pattern located on the bottom surface, in The negative potential pattern includes a void at the center thereof, The void surrounds the at least one opening, The negative potential pattern and the collector pattern are offset relative to each other, The negative potential pattern is positioned along at least a portion of at least three of the four edges of the sensor without contacting the at least portion, The negative potential pattern is positioned along the entire first edge of the sensor, The negative potential pattern is positioned along a portion of the second edge and the third edge of the sensor, and The first edge of the sensor is located between the second edge and the third edge of the sensor.

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