TEST PATCH SYSTEM AND METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[001] This application claims the benefit of copending U. S. Provisional Patent Application Serial Number 60/949,737 filed July 13, 2007 and entitled "Test Patch System and Method".

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[002] The present invention relates generally to a system for surface contaminant testing and more specifically to a system and method for testing a surface for at least one property such as pH, the presence of chlorides, or conductivity as a measure of the efficacy of a surface treatment applied to said surface.

DESCRIPTION OF THE RELATED ART

[003] In industrial applications where the treatment of surfaces with protective coatings is regularly used, it is often necessary to test various portions of the treated surfaces to determine whether the protective coating has been properly applied. Alternatively, prior to the treatment of, for example, steel surfaces, the surfaces must be thoroughly cleaned of contaminants and salts such as chloride salts so that corrosion doesn't occur under a treated or painted surface. Accordingly, there are various and sundry prior art systems for determining the presence of contaminants of various types on surfaces.

proximity of steel to ocean air and water, as w as less otn ious causes such as salt treatment of ic> roads in proximity to the untreated mateπal Corrosion can occur quite rapidly after a surface is contaminated and as such, surfaces must be cleaned, tested and treated quickly m order to avoid the deleterious effects which will eventuallv appear when a contaminated surface is treated or coated Furthermore, pamtmg o\er a chloride contaminated surface causes failure in immersion service materials such as ballast tanks and the like which of course carries an enormous inconvenience and expense to repair

[005] Many prior art devices capable of testing surfaces for \ anous properties such as salmitv. pH, or conductivity are typically complex and labor intensive assemblies that require a multiplicity of steps in order Io accomplish the surface testing In one popular example, a Breslc patch or sampler has been used as a means for measuring chloπde contamination on treated surfaces The Bresle patch composes a latex membrane and a foam rubber gasket that creates a water tight sample extraction pocket m contact with a surface when a foam rubber gasket is secured to the surface \ia an adhesiv e The w atertight sample extraction pocket is then filled with distilled or deiomzed water. tvpicalrv by use of a svringe After agitating the water by rubbing the patch for a short time period, the water is removed, typically through a sjrmge or the like, then anah zed by chemical reagents for a constituent propertj such as chloπde ion content The chemical analysis is typically done by using a "kit" supplied with reagents and instructions for use The extracted water may also be anah zed for other properties such as pH, clcctncal conductivity , or the presence of chlondc ions using conventional known-m-the art meters designed for those purposes

[006] Other methods of testing a surface for a constituent propertv are also known in the art but each of them requires a large amount of time and energy to collect and analyze a single sample In many prior art systems, \ arious syringes, bottles of water and reagents, surface test patches and other equipment must be coordinated and assembled in an inhospitable industrial fabrication environment These prior art methods are quite disadvantageous when testing large surface areas, since samples must be collected at many points around the area being treated in a short time before surface treatment can proceed

[007J Accordingly, there is a need in the art for a system and method of testing for a constituent property of a surface that is capable of being conducted repeatedly and quickly by a user while yielding consistently accurate results

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[008 J Fig 1 is a plan view of a test patch system in accordance with one embodiment of the present invention

[009] Fig 2 is an exploded elevation view of a test patch system in accordance with one embodiment of the present im ention

[010] Fig 3 is an elevation view of a test patch s> stem m accordance with one embodiment of the present invention

[011] Fig 4 is a top schematic view of a test patch s> stem in accordance with one embodiment of the present invention

[012] Fig 5 is a side schematic view of a test patch system in accordance with one embodiment of the present invention

[013] Fig 6 is a top view of a tack strip m accordance with one embodiment of the present invention

[014] Fig 7 is a view of a tack strip taken along the line 7-7 in accordance with one embodiment of the present invention

[015] Fig 8 is an isometric view of a tack strip and a test patch system in accordance with one embodiment of the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[016] Referring now to Figs 1-5 and in accordance with one embodiment of the present invention, a test patch sy stem 10 for testing a surface 2 for the presence of a constituent property comprises a solvent 3 supply ampoule 20, mid a test patch 100 comprising a transition region 150. an extraction region 200 and a collection region 250 Surface 2 may be any one of a plurality of surfaces on which a constituent may be present In one embodiment of the present invention, surface 2 comprises a metal surface, used for example as a component of a marine vessel In this exemplary embodiment of the invention 10, the constituent to be detected may be a chloride, which may have deleterious effects on an unpainted or coated surface, and which must be removed pπor to painting or coating to prevent the ultimate failure of the coating

[017] Ampoule 20 contains a supply of a sohent 3, such as distilled water 3 used to saturate a media for extracting the constituent, as will be discussed further below The distilled water 3 (or other solvent as required by an individual application) contained m ampoule 20 remams separated from system 100 by a membrane 22 or stopper disposed proximate an outlet area of ampoule 20 until the system is ready to be used The

membrane 22 of ampoule 20 may be pierced b> an end portion 152 of transition region 150 when system 10 is ready for use In one embodiment of the present invention, end portion 152 may be shaped or narrowed to a point to facilitate the piercing of membrane 22 Alternatively , membrane 22 may be designed to rupture to release water into transition region 150 -when ampoule 20 is pressurized by . for example, squeezing

[018] In a yet further embodiment of the invention, a foam stopper 58 or the like may be included in an outlet portion of ampoule 20, or in transition region 150. that is ruptured or opened upon engagement of ampoule 20 with transition region 150 end portion 152 Furthermore, it should be noted that ampoule 20 may be provided as a separate and distinct component to system 10. such that a \ariety of different ampoules 20 may be employed in conjunction with the invention by inserting ampoule 20 onto or into end portion 152 of transition region 150

[019] Test patch 100 may comprise a backplane 110 upon -which the components of patch 100 are mounted or assembled Backplane 110 may comprise a watertight layer, which m an exemplary embodiment is formed of polycarbonate material Backplane 110 may extend substantially the entire length of test patch system 10 for both ease of assembly, and to provide a substrate for the mounting and positioning of the remaining elements of system 110. as discussed in detail below

[020] Referring now to Figs 1 , 4 and 5 transition region 150 may comprise a plurality of layers Backplane 110 is secured to capillar}' plastic layer 154 that is designed to transport water from ampoule 20, through transition region 150 and into extraction region 200 Additionally, a sipper lid 156. formed of a watertight plastic material, is provided as a layer co\errng capillary layer 154 such that capillars layer 154

is enclosed on the top and bottom by backplane 110 and sipper lid 156 Accordingly water 3 must flow from ampoule 20 through capillary layer 154 thence into extraction region 200 The fluid flow dynamics of the present indention are best viewed with reference to Figs 4 and 5 which depict schematically the component layers of the invention 10 and their interconnections

[021] Transition region 150 connects to and abuts extraction region 200 as seen in Figs 1, 2 and 3 through a plurality of component layers As best seen in Figs 1 and 2, the demarcation between transition region 150 and extraction region 200 is not at a single layer or surface, but rather is a transition through a plurality of material layers

[022] Extraction region 200 comprises backplane layer 1 10, which provides an upper patch surface that is oriented away from the surface 2 being tested Furthermore, backplane layer 110 provides structural support for the transition region 150, the extraction region 200, and the collection region 250 and their dimensional relationship to each other Adjacent to backplane 110 m extraction region 200 is a is a watertight closed cell foam layer 204 having an adhesive lay cr 206 thereon, which secures a flexible, watertight support layer 207 Support layer 207 may be comprised of, for example, a 010 " thick polycarbonate plastic Support layer 207 is adjacent and connected to a sample collection material 208 which is comprised of a pad of absorbent fibers which pro\ides a flow path for water 3 entering collection material 208 defined b\ the orientation of the fibers therein As long as material 208 and reseπoir 252 are not both completely saturated with water 3, material 208 pro\ides a defined flow path for water 3 while preventing water 3 leakage from side portions of material 208

Additionally, collection material 208 composes a contact region 209 that co\ers a predetermined surface area of the surface 2 bemg tested

[023] Support layer 207 may completely co\er the adjacent surface of collection material 208 and be in intimate contact therewith Additionally, an adhesn e layer may be pro\idcd between collection material 208 and support la>cr 207 to maintain intimate contact between the two layers In a yet further embodiment of the present invention, contact between support layer 207 and collection material 208 is maintained by installing collection material 208 tightly stretched across support layer 207 and securing it thereto with an adhesive, or alternatively b> mechanical compression where collection material 208 contacts backplane 110 at either end of extraction region 200

[024] Foam layer 204 is compressible but resilient to resist compressive forces Stated another way , foam layer 204 may be elastic m nature Additionally, since support layer 207 is flexible, foam layer 204 and support layer 207 work in concert to assure that, when collection material 208 is m contact with a sample surface and pressure is applied to backplane 110 proximate extraction region 200, collection material 208 conforms to a plurality of surface geometries while maintaining contact between material 208 contact region 209 and surface 2 In this fashion rough, uneven, cuπ ed, flat of irregular surfaces often found m many surface testing environments cmironments. such as untreated steel, boat hulls, pipes etc may be accurately tested since the contact region 209 (and thus the predetermined contact area) is maintained σver a broad variety of surfaces 2 The invention is therefore capable of maintaining a reproducible contact area between patch 10 and surface 2 which enables the accurate

determination of, for example, the concentration of a mass of contaminant m a predetermined unit area

[025] Sample collection material 208 may compnse a plurality of materials that are capable driving the capillary flow of water 3 through said material 208 while simultaneously extracting salts or other constituents from surface 2 m contact with contact region 209 In one embodiment of the present invention, collection material 208 comprises a lay er or la> ers of absorbent fiber material that prσv ides a flow transport mechanism from sample surface 2 to collect a constituent sample Other exemplary collection materials 208 include v arious sponge-like materials felt fiber mats, paper fiber mats, or spun fiber mats made from synthetic or natural materials that provide a suitable capillary force or action to draw the water solvent 3 across extraction region 200 while keeping water in continuous contact with the surface and that are suitable for conforming to rough uneven surfaces Collection material 208 is in fluid communication with capillary layer 154 such that material 208 is saturated with distilled water supplied by ampoule 20 Collection material 208 may have capillary and surface tension properties that enable solvent 3 (which m one embodiment is de-ionized water) to be wicked through collection material 208 to contact surface 2 through contact area 209, and further prevents solvent 3 from exiting or leaking from the edges of collection material 208 Accordingly , collection material 208 may hav e a plurality of capillary fibers oriented from transition region to collection region 250, to inhibit this aforementioned solvent 3 loss

[026] Additionally, collection material 208 may be comprised of absorbent fibers or equiv alent materials which permit fluid 3 flow from a front portion of collection

material 208 (that portion proximate transition region 150) to a rear portion thereof (that portion proximate collection region 250) and to and from any area of said surface 2 that is in contact with collection mateπal 208, while preventing fluid 3 escaping from the sides of collection material 208 and from the perimeter of an area of said surface 2 in contact w ith said collection material 208 at contact area 209 This feature of the invention ensures that fluid 3 is not "lost" or leaked away from surface 2, thereby diluting the constituents present on the surface and providing an inaccurate reading of constituent concentration In one embodiment of the invention, collection material 208 may comprise a pad of absorbent fibers for drawing water or solvent 3 into and through collection material 208

[027] Referring now to Figs 6, 7 and 8 the invention further comprises a tack strip 300 which ma> comprise a flexible strip of plastic mateπal having a lav er or coating of adhesive mateπal on one side thereof for contacting both test patch 10 and surface 2, thus securing patch 10 thereto More specifically, tack strip 300 has two ends 302 that are secured via adhesive to surface 2, while a center section 304 is secured via adhesive to backplane 110 directly over extraction region 200, as shown in Fig 8 Extraction region 200 contact area 209 is thus forced into intimate contact with surface 2 by tack strip 300, by simply pressing tack strip 300 over backplane 110 (directly over extraction region 200) and onto surface 2 Tack strip 300 is preferably oriented at right angles to a longitudinal axis of test patch 10

[028] Tack strip 300 is elastic or spring-like, such that it applies pressure across the entire extraction region 200 and maintains contact with surface 2 at end portions 302 such that contact area 209 maintains contact with surface 2 Additionally, since foam

la>cr 204 and support layer 207 act to accurately and evenly distribute force across contact area 209, tack strip 300 provides a simple and efficient mechanism for maintaining contact between collection material 208 and surface 2 One of ordinary skill will recognize that a wide variety of clamping or spring mechanisms may be used in place of tack strip 300 without departing from the scope of the present invention Additionally, in one embodiment of the present invention, tack strip 300 may be provided with an adhesive release layer 306, for example a thin plastic film, that covers tack stπp 300 to protect the adhesive thereon until tack strip 300 is ready to be used

[029J Extraction region 200 transitions into and connects to collection region 250 where the solution of water 3 (or other solvent) and extracted salts (or oilier constituent) is collected for further analysis Collection region 250 comprises a fluid reservoir 252 that may be sized to contain a greater volume of fluid than that contained in extraction region 100 This feature of the present invention permits a positive fluid flow from extraction region 200 to collection region 250. thereby providing more consistent samples In one embodiment of the invention, reservoir 252 is ten times the volume of the fluid capable of being in extraction region 200 Reservoir 252 is in contact with, and in fluid communication with collection material 208. thereby providing for fluid transport between extraction region 200 and collection region 250 The dimension and surface tension properties of capillary layer 154 and fluid reservoir 252 provide a driving force to pull solvent 3, and thus extracted salts or other constituents, out of collection material 208 into fluid reservoir 252

[030] In another embodiment of the present invention, reservoir 252 may contain collection material 208 or an equivalent fiber mat collection material to assist fluid flow

from extraction region 200 to collection region 250 and to contain the solvent 3 sample to be tested The fluid 3 collected m reservoir 252 is in contact with an electrical layer 254 that ma> comprise a substrate 256 having a plurality of electrodes 258 printed or deposited thereon for analyzing solution 3 collected in reservoir 252 Electrical layer 254 may be disposed generally between backplane 110 and reservoir 252 such that electrodes 258 are accessible to connect to a signal generator or reader (not shown) Additionally, in an alternative embodiment of the invention, elcctπcal layer 254 may be pπnted or deposited directly onto backplane 110 thereby enhancing ease of assembly and reducing material costs Finally, reservoir 252 and electrical layer 254 may be enclosed by a w atertight plastic membrane 260 to facilitate assembly of test patch 10 In one embodiment of the invention, a portion of electrodes 258 may remain unco\ ered b> membrane 260 to facilitate electrical connections to a reader (not shown)

[031] As best seen m Fig 1 , a capillary channel 270 is provided in backplane 110 and is in contact with reservoir 252 such that fluid 3 flow through capillary channel 270 and across a dye spot 272 deposited in capillary channel 270 Capillary channel 270, dye spot 272, and electrical layer 254 may be covered by a watertight plastic layer 276 through which a hole 274 is bored Hole 274 permits air to escape while reservoir 252 is filling with water Dye spot 272 may comprise a small quantity of fluorescent dye, for example At an end of capillary channel 270 a hole 274 permits air to escape while reservoir 252 is filling with water Once reservoir 252 is filled with w ater 3, water is pulled mto capillary channel 270 therein forcing dye from dye spot 272 up the capillary channel This streak or line of dye thus prov ides a v isual indication to an operator or user that reservoir 252 is full and that test patch 100 is ready to be analyzed or read In

another embodiment of the indention, electrical layer 254 may include additional electrodes 280 that are positioned across capillary layer 270 proximate each other In this embodiment of the invention, a signal can be provided across electrodes 280 to validate that the capillary channel 270 contains water and thus that test patch 100 is readj for analy sis

[032] In an alternative embodiment of the invention, a flexible wire or similar material may run longitudmall} along a substantial length of s> stem 10 to permit portions thereof to be flexed and bent into configurations amenable to surface mounting For example, ampoule 20 and a portion of transition region 150 may be oriented to ensure water flow to extraction region 200 b> simply bending the wire

[033] In operation, the system is used by inserting ampoule 20 over end 152 of transition region 150 to initiate water flow through capillary lajer 154 into extraction region 200 Adhesive release layer 306 is removed and lest patch system 10 is secured onto a surface 2 to be tested such that tack strip 300 and collection material 208 arc in contact with surface 2 Alternatively, test patch system 10 may be secured to the test surface 2 using taek stπp 300 prior to inserting ampoule 20 over end 1^2 of transition region 150 Water 3 and collected salts flow through capillary layer 154 into collection material 208. thence into reservoir 252 Once dye spot 272 indicates that capillary channel 270 contains fluid, test patch sy stem 10 is removed from the surface, whereupon electrodes 258 are electrically connected to a reader that supplies a known electrical signal thereto and calculates the conductivity of the solution contained in reservoir 252 from the attenuation detected in said signal, as is generally known in the art

[034] While the present indention has been discussed in the context of measuring salts and the conductrvitv thereof on a surface being tested, one of ordinary skill will recognize that a v aπetv of printed sensors and electrodes for measuring a pluralitv of constituents mav be employed as an electrical layer 214 in the test patch 100 of the present invention without departing from the scope thereof As one example, a thermistor may be included in electrical layer 254 to permit for temperature corrections of constituent data taken using the system and method of the present invention This is particularh useful when the measurement of constituent data is temperature sensitive, or when multiple constituents are being tested

[035] In a yet further embodiment of the present im ention reserv oir 252 or transition region 150 may be doped or infused with chemical reagents to selectively react with specific constituents in predetermined chemical reactions In one embodiment the reagents may effect a color change m the solvent being used to provide visual indicia of the presence or absence of specific constituents like chlorides Alternatrvel} the chemical reagent utilized to dope reseπ oir 252 or transition region 150 ma) modifv the properties of the extracted solution such that test patch 100 measurement is specific to a selected constituent in the extracted solution

[036] While the present inv ention has been show n and described herein in what are considered to be the preferred embodiments thereof, illustrating the results and adv antages ov er the prior art obtained through the present invention, the invention is not limited to those specific embodiments Thus, the forms of the invention shown and described herein are to be taken as illustrative onlv and other embodiments may be

selected without departing from the scope of the present invention, as set forth in the claims appended hereto