Abstract:
An explosion tester system comprising a body, a lateral flow membrane swab unit adapted to be removeably connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/583,161 filed Jun. 24, 2004 and titled “Spot Test Kit for Explosives Detection.” U.S. Provisional Patent Application No. 60/583,161 filed Jun. 24, 2004 and titled “Spot test Kit for Explosives Detection” is incorporated herein by this reference. 
     
    
       [0002]     The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory. 
     
    
     BACKGROUND  
       [0003]     1. Field of Endeavor  
         [0004]     The present invention relates to explosives and more particularly to testing for the presence of explosives.  
         [0005]     2. State of Technology  
         [0006]     U.S. Pat. No. 5,638,166 for an apparatus and method for rapid detection of explosives residue from the deflagration signature thereof issued Jun. 10, 1997 to Herbert O. Funsten and David J. McComas and assigned to The Regents of the University of California provides the following state of the art information, “Explosives are a core component of nuclear, biological, chemical and conventional weapons, as well as of terrorist devices such as car, luggage, and letter bombs. Current methods for detecting the presence of explosives include vapor detection, bulk detection, and tagging. However, these methods have significant difficulties dependent upon the nature of the signature that is detected. See Fetterolf et al., Portable Instrumentation: New Weapons in the War Against Drugs and Terrorism,” Proc. SPIE 2092 (1993) 40, Yinon and Zitrin, in Modern Methods and Applications in Analysis of Explosions, (Wiley, N.Y., 1993) Chap. 6; and references therein. Vapor detection is achieved using trained animals, gas chromatography, ion mobility mass spectrometry, and bioluminescence, as examples. All of these techniques suffer from the inherently low vapor pressures of most explosives. Bulk detection of explosives may be performed using x-ray imaging which cannot detect the explosives themselves, but rather detects metallic device components. Another method for bulk detection involves using energetic x-rays to activate nitrogen atoms in the explosives, thereby generating positrons which are detected. This technique requires an x-ray generator and a minimum of several hundred grams of explosives. Bulk detection is also accomplished using thermal neutron activation which requires a source of neutrons and a .gamma.-radiation detector. Thus, bulk detection is not sensitive to trace quantities of explosives and requires large, expensive instrumentation. Tagging requires that all explosives be tagged with, for example, an easily detected vapor. However, since tagging is not mandatory in the United States, this procedure is clearly not reliable. It turns out that there are no technologies for performing accurate, real-time (&lt;6 sec) detection and analysis of trace explosives in situ. Only trained dogs can achieve this goal.  
         [0007]     It is known that surfaces in contact with explosives (for example, during storage, handling, or device fabrication) will readily become contaminated with explosive particulates as a result of their inherent stickiness. This phenomenon is illustrated in studies that show large persistence of explosives on hands, even after several washings (J. D. Twibell et al., “Transfer of Nitroglycerine to Hands During Contact with Commercial Explosives,” J. Forensic Science 27 (1982) 783; J. D. Twibell et al., “The Persistence of Military Explosives on Hands,” J. Forensic Science 29 (1984) 284). Furthermore, cross contamination in which a secondary surface is contaminated by contact with a contaminated primary surface can also readily occur. For example, a measurable amount of ammonium nitrate (AN) residue has been found on the lease documents for a rental truck, and significant amounts of the explosives PETN (pentaerythritol tetranitrate) and/or AN have been found on clothing and inside vehicles of suspects in two well-publicized bombings. Therefore, explosive residue will likely persist in large amounts on the explosive packaging and environs, as well as on the individuals involved in building the explosive device, which can provide an avenue for detection of the presence of explosives.  
         [0008]     U.S. Pat. No. 5,679,584 for a method for chemical detection issued Oct. 2, 1997 to Daryl Sunny Mileaf and Noe Esau Rodriquez, II provides the following state of the art information, “a method for detecting a target substance which includes collecting a substance sample; introducing the substance sample into a substance card having at least one preselected reagent responsive to the presence of the target substance and having a light-transmissive chamber; and inserting the substance card into a substance detector device having a photosensor and adapted to receive the substance card. Once the substance detector card has been inserted into the substance detector, the method continues by mixing the substance sample with the preselected reagents for a preselected mixing period, thus producing a measurand having a target substance reaction.” 
         [0009]     U.S. Pat. No. 6,470,730 for a dry transfer method for the preparation of explosives test samples issued Oct. 29, 2002 to Robert T. Chamberlain and assigned to The United States of America as represented by the Secretary of Transportation provides the following state of the art information, “ . . . method of preparing samples for testing explosive and drug detectors of the type that search for particles in air. A liquid containing the substance of interest is placed on a flexible Teflon® surface and allowed to dry, then the Teflon® surface is rubbed onto an item that is to be tested for the presence of the substance of interest. The particles of the substance of interest are transferred to the item but are readily picked up by an air stream or other sampling device and carried into the detector.” 
       SUMMARY  
       [0010]     Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.  
         [0011]     The preset invention provides an inspection tester system for testing a suspect surface for explosives. The system includes the step of providing a lateral flow membrane swab unit; providing a first explosives detecting reagent; providing a second explosives detecting reagent; swiping the suspect surface with the lateral flow membrane swab unit, delivering the first explosives detecting reagent to the lateral flow membrane swab unit, wherein if the lateral flow membrane swab unit becomes colored the test is positive for explosives and if no color appears the test for explosives is negative to this point; and delivering the second explosives detecting reagent to the lateral flow membrane swab unit, wherein if the lateral flow membrane swab unit becomes colored the test is positive for explosives and if no color appears the test for explosives is negative. The inspection tester system comprises a body, a lateral flow membrane swab unit adapted to be removable connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.  
         [0012]     The inspection tester of the present invention provides a simple, chemical, field spot-test to provide a rapid screen for the presence of a broad range of explosive residues. The inspection tester is fast, extremely sensitive, low-cost, very easy to implement, and provides a very low rate of false positives. The inspection tester for explosives provides a fast, sensitive, low-cost, very easy to implement system for testing the suspected packages. The inspection tester for explosives is inexpensive and disposable. The inspection tester for explosives has detection limits between 0.1 to 100 nanograms, depending on the type of explosives present. A large number of common military and industrial explosives can be easily detected such as HMX, RDX, NG, TATB, Tetryl, PETN, TNT, DNT, TNB, DNB and NC. The inspection tester is small enough that a number of them can fit in a pocket or brief case.  
         [0013]     The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate specific embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the specific embodiments, serve to explain the principles of the invention.  
         [0015]      FIG. 1  illustrates an embodiment of the invention.  
         [0016]      FIG. 2  shows the removable swab unit in greater detail.  
         [0017]      FIG. 3  shows the explosive tester positioned in a portable heating unit.  
         [0018]      FIG. 4  shows another embodiment of an inspection tester for explosives constructed in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Referring now to the drawings, to the following detailed description, and to incorporated materials, detailed information about the invention is provided including the description of specific embodiments. The detailed description serves to explain the principles of the invention. The invention is susceptible to modifications and alternative forms. The invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.  
         [0020]     The ability to identify unknown explosives in the field is of utmost importance to the military, law enforcement and Homeland security forces worldwide. There have been many reports of the use of spot tests for the identification of explosives, some of which are listed below. They have been used in combination with thin-layer chromatography and in forensic analysis. There are some commercial companies (Mistral, Securesearch, Duram products) who have produced explosives identification kits similar to the one Applicants propose. They have incorporated similar color reagents and have been used by the military and law-enforcement agencies. Ex-spray and Duram products are probably the best commercial test kits produced thus far. They allow the identification of nitroaromatics, nitramines, ammonium nitrate, and recently the potassium chlorate-based explosives. Their systems are available as spray kits or solution-drop kits. The Duram product will also identify the peroxide explosives. Another company produced a swab kit that incorporates either diphenylamine or Wurster&#39;s salt that turns blue when it comes in contact with nitramines, oxidizers and nitrate esters. It is easy to use but is non-specific and would give a significant number of false positives.  
         [0021]     Referring now to  FIG. 1  of the drawings, an embodiment of an inspection tester for explosives constructed in accordance with the present invention is illustrated. This embodiment of the present invention is designated generally by the reference numeral  100 . The inspection tester  100  is an all-inclusive, inexpensive, and disposable device. The inspection tester can be used anywhere as a primary screening tool by non-technical personnel to determine whether a surface contains explosives. The inspection tester  100  was developed to allow identification of explosives. This inspection tester may be used by first responders, military, law enforcement and Homeland Security.  
         [0022]     The inspection tester  100  provides a small, disposable, one use system. The inspection tester  100  uses a simple and rapid method of operation. A removable swab unit sample pad  101  is exposed to a suspect substance. This may be accomplished by the swab unit sample pad  101  being swiped across a surface containing the suspect substance or the swab unit pad  101  may be exposed to the suspect substance in other ways such as adding the suspect substance to the swab unit sample pad  101 .  
         [0023]     The inspection tester  100  comprises an explosives tester body  102  and the removable swab unit  101  adapted to be removably positioned in the explosives tester body  102 . The removable swab unit  101  includes a lateral flow membrane  111 , an area  112  so that the swab unit can be easily inserted and removed from the explosives tester body  102 . The removable swab unit  101  also includes an information area  113  and color reaction indicators  114 .  
         [0024]     The explosives tester body  102  includes a printable backing card  103  that adds stiffness and infographics. A heat seal pattern  104  adds strength to avoid warping. A section  105  of the explosives tester body  102  provides an area for printed graphics and thumb placement and step numbering. The explosives tester body  102  includes a beveled docking entry portion  106  and a tab  107  for easy docking of the removable swab unit sample pad  101 .  
         [0025]     The explosives tester body  102  also includes ampoule A  108  and ampoule B  109 . In various embodiments, ampoule A  108  and ampoule B  109  are breakable ampoules, breakable glass ampoules, squeezable ampoules, and other types of ampoules. As shown in  FIG. 1 , ampoule A  108  includes indentations  110  on the chamber which keeps glass pieces from adhering to the walls.  
         [0026]     The removable swab unit  101  is shown in greater detail in  FIG. 2 . The tab area  112  is provided so that the swab unit  101  can be easily inserted and removed from the explosives tester body  102 . The lateral flow membrane  111  makes up the bulk of the removable swab unit  101 . The lateral flow membrane  111  comprises a microporous membrane that provides migration of fluids from ampoule A  108  and fluids from ampoule B  109 . Lateral flow membranes are known for their use in other fields such as blotting techniques, enzyme-linked immunosorbent assay (ELISA) testing, and lateral-flow immunochromatographic tests. The lateral flow membrane  111  is a Porex Lateral-Flo Membrane. The lateral flow membrane  111  comprises polyethylene spheres fused into a lateral-Flo™ membrane. Applicants experimentally determined that the properties of Porex make it an ideal swipe material for the inspection tester  100 . The lateral flow membrane  111  is chemical resistant, withstands heat as high as 130° C., is durable, is inexpensive, can be cut to any size, and concentrates suspect materials along the solvent front making colorimetric detection limits. The lateral flow membrane  111  provides a high surface area swipe for sample collection.  
         [0027]     Referring now to  FIG. 3 , the removable swab unit  101  of the explosive tester  100  is shown as it would be positioned in a portable heating unit  300 . The portable heating unit  300  can be an electrical heater or, alternatively, the portable heating unit  300  can be another type of heating unit such as a chemical heater. The heating element  301  is activated and the removable swab unit  101  will be heated as hereinafter described. The details of the portable heating unit  300  are well known in the art and need not be described here.  
         [0028]     Ampoule A  108  and ampoule B  109  provide two reagent activation units. Ampoule A  108  (for reagent A) and ampoule B  109  (for reagent B) are operatively mounted on the explosives tester body  102 . The ampoule A  108  containing the first explosives detecting reagent A is positioned to deliver the first explosives detecting reagent A to the lateral flow membrane  111 . The Ampoule B  109  containing the second explosives detecting reagent B is positioned to deliver the second explosives detecting reagent B to the lateral flow membrane  111 . The reagent A contains Meisenheimer complexes. The reagent B provides a Griess reaction. The Meisenheimer complexes and Griess reaction are well known in the art and need not be described here.  
         [0029]     The structural details of embodiment of an inspection tester for explosives constructed in accordance with the present invention having been described the operation of the inspection tester  100  will now be considered. The inspection tester  400  uses a simple and rapid procedure summarized by the following four step operation:  
         [0030]     STEP 1) A suspect surface is swiped with the removable swab unit sample pad  101 . This may be accomplished by the swab unit sample pad  101  being swiped across a surface containing the suspect substance or the swab unit pad  101  may be exposed to the suspect substance in other ways such as adding the suspect substance to the swab unit sample pad  101 . This will cause any explosives residue to be collected and held by the swab unit sample pad  101 .  
         [0031]     STEP 2) The breakable or squeezable ampoule A  108  is located in a position to deliver the first explosives detecting reagent A to the lateral flow membrane  111 . The breakable or squeezable ampoule A  108  is pressed to break or squeeze it thereby dispensing reagent A onto the lateral flow membrane  111 . The regent A contacts any explosives residue that has been collected by the swab unit sample pad  101 . The lateral flow membrane  111  concentrates suspect materials along the solvent front. If the swab unit sample pad  101  becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative to this point.  
         [0032]     STEP 3) If STEP 2 is negative to this point, the inspection tester  100  is positioned in the portable heating unit  300 . The heating unit  300  is activated. This causes the swab unit sample pad  101 , reagent A, and any explosives residue to become heated. If the swab unit sample pad  101  now becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative to this point.  
         [0033]     STEP 4) The breakable or squeezable ampoule B  109  is located in a position to deliver the second explosives detecting reagent B to the lateral flow membrane  111 . If STEP 3 is negative to this point, the breakable or squeezable ampoule B  109  is pressed to brake or squeeze it thereby dispensing reagent B onto the lateral flow membrane  111 . The regent B contacts any explosives residue that has been collected by the swab unit sample pad  101 . The lateral flow membrane  111  concentrates suspect materials along the solvent front. If the swab unit sample pad  101  becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative.  
         [0034]     The inspection tester  100  provides a simple, chemical, field spot-test by to provide a rapid screen for the presence of a broad range of explosive residues. The lateral flow membrane  111  is microporous cellulose nitrate membrane that provides migration of the fluids from ampoule A  108  and ampoule B  109 . The lateral flow membrane  111  concentrates suspect materials along the solvent front. This concentration makes the explosives tester  100  more sensitive because by concentrating any explosives particles along the solvent front a larger amount of materials in one place. The color that will be produced by the reagents from ampoule A  108  and ampoule B  109  will be easier to see.  
         [0035]     The inspection tester  100  is fast, extremely sensitive, low-cost, very easy to implement, and provides a very low rate of false positives. The inspection tester for explosives  100  provides a fast, sensitive, low-cost, very easy to implement system for testing the suspected packages. The inspection tester for explosives  100  is inexpensive and disposable. The inspection tester for explosives  100  has detection limits between 0.1 to 100 nanograms, depending on the type of explosives present. A large number of common military and industrial explosives can be easily detected such as HMX, RDX, NG, TATB, Tetryl, PETN, TNT, DNT, TNB, DNB and NC. The inspection tester  100  is small enough that a number of them can fit in a pocket or brief case.  
         [0036]     Referring now to  FIG. 4  of the drawings, another embodiment of an inspection tester for explosives constructed in accordance with the present invention is illustrated. This embodiment of the present invention is designated generally by the reference numeral  400 . A removable swab unit sample pad  401  is exposed to a suspect substance. This may be accomplished by the swab unit sample pad  401  being swiped across a surface containing the suspect substance or the swab unit pad  401  may be exposed to the suspect substance in other ways such as adding the suspect substance to the swab unit sample pad  401 .  
         [0037]     The inspection tester  400  comprises an explosives tester body  402  and the removable swab unit  401  adapted to be removably positioned in the explosives tester body  402 . The removable swab unit  401  includes a lateral flow membrane  411 , an area  412  so that the swab unit can be easily inserted and removed from the explosives tester body  402 . The removable swab unit  401  also includes and information area  413  and color reaction indicators  414 .  
         [0038]     The explosives tester body  402  includes a printable backing card  403  that adds stiffness and infographics. A heat seal pattern  404  adds strength to avoid warping. A section  405  of the explosives tester body  402  provides an area for printed graphics and thumb placement and step numbering. The explosives tester body  402  includes a beveled docking entry portion  406  and a tab  407  for easy docking of the removable swab unit sample pad  401 .  
         [0039]     The explosives tester body  402  also includes three ampoules, #1 ampoule A  408 , #2 ampoule B  409 , and #3 ampoule C  410 . In various embodiments, ampoule A  408 , ampoule B  409 , and ampoule C  410  are breakable ampoules, breakable glass ampoules, squeezable ampoules, and other types of ampoules. As shown in  FIG. 4 , ampoule A  408  includes indentations  110  on the chamber which keeps glass pieces from adhering to the walls.  
         [0040]     The tab area  412  on the removable swab unit  401  allows the swab unit  401  can be easily inserted and removed from the explosives tester body  402 . The lateral flow membrane  411  makes up the bulk of the removable swab unit  401 . The lateral flow membrane  411  comprises a microporous cellulose nitrate membrane that provides migration of fluids from ampoule A  408 , fluids from ampoule B  409 , and fluids from ampoule C  410 . The lateral flow membrane  411  is a Porex Lateral-Flo Membrane. The lateral flow membrane  411  comprises polyethylene spheres fused into a Lateral-Flo™ membrane. The lateral flow membrane  411  is chemical resistant, withstands heat as high as 130° C., is durable, is inexpensive, can be cut to any size, and concentrates suspect materials along the solvent front making colorimetric detection limits. The lateral flow membrane  411  provides a high surface area swipe for sample collection.  
         [0041]     Ampoule A  408 , ampoule B  409 , and ampoule C  410  and provide three reagent activation units. Ampoule A  408  (for reagent A), ampoule B  409  (for reagent B) and ampoule C  410  (for reagent C) are operatively mounted on the explosives tester body  402 . The ampoule A  408  containing the first explosives detecting reagent A is positioned to deliver the first explosives detecting reagent A to the lateral flow membrane  411 . The ampoule B  409  containing the second explosives detecting reagent B is positioned to deliver the second explosives detecting reagent B to the lateral flow membrane  411 . The ampoule C  410  containing the third explosives detecting reagent C is positioned to deliver the third explosives detecting reagent C to the lateral flow membrane  411 . The reagent A contains Meisenheimer complexes. The reagent B provides a Griess reagent. The reagent C provides a Nesslers reagent. The Meisenheimer complexes, Griess reagent, and Nesslers reagent are well known in the art and need not be described here.  
         [0042]     The structural details of embodiment of an inspection tester for explosives constructed in accordance with the present invention having been described the operation of the inspection tester  400  will now be considered. The inspection tester  400  uses a simple and rapid procedure summarized by the following steps:  
         [0043]     STEP 1) A suspect surface is swiped with the removable swab unit sample pad  401 . This may be accomplished by the swab unit sample pad  401  being swiped across a surface containing the suspect substance or the swab unit pad  401  may be exposed to the suspect substance in other ways such as adding the suspect substance to the swab unit sample pad  401 . This will cause any explosives residue to be colleted and held by the swab unit sample pad  401 .  
         [0044]     STEP 2) The breakable or squeezable ampoule A  408  is located in a position to deliver the first explosives detecting reagent A to the lateral flow membrane  411 . The breakable or squeezable ampoule A  408  is pressed to break or squeeze it thereby dispensing reagent A onto the lateral flow membrane  411 . The regent A contacts any explosives residue that has been collected by the swab unit sample pad  401 . The lateral flow membrane  411  concentrates suspect materials along the solvent front. If the swab unit sample pad  401  becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative to this point.  
         [0045]     STEP 3) If STEP 2 is negative to this point, the breakable or squeezable ampoule B  409  is pressed to brake or squeeze it thereby dispensing reagent B onto the lateral flow membrane  411 . The breakable or squeezable ampoule B  409  is located in a position to deliver the second explosives detecting reagent B to the lateral flow membrane  411 . The regent B contacts any explosives residue that has been collected by the swab unit sample pad  401 . The lateral flow membrane  411  concentrates suspect materials along the solvent front. If the swab unit sample pad  401  becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative to this point.  
         [0046]     STEP 4) If STEP 3 is negative to this point, the breakable or squeezable ampoule C  410  is pressed to brake or squeeze it thereby dispensing reagent C onto the lateral flow membrane  411 . The breakable or squeezable ampoule C  410  is located in a position to deliver the second explosives detecting reagent C to the lateral flow membrane  411 . The regent C contacts any explosives residue that has been collected by the swab unit sample pad  401 . The lateral flow membrane  411  concentrates suspect materials along the solvent front. If the swab unit sample pad  401  becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative to this point.  
         [0047]     STEP 5) If any of the various STEPS 2, 3, and 4 are negative and greater sensitivity is desired, the inspection tester  400  can be positioned in a heating unit. This causes the swab unit sample pad  401 , reagents A, B, and/or C and any explosives residue to become heated. If the swab unit sample pad  401  now becomes colored, the test is positive for explosives. If no color appears the test for explosives is negative.  
         [0048]     The inspection tester  400  provides a simple, chemical, field spot-test by to provide a rapid screen for the presence of a broad range of explosive residues. The lateral flow membrane  411  is microporous cellulose nitrate membrane that provides migration of the fluids from ampoule A  408 , ampoule B  409 , and ampoule C  410 . The lateral flow membrane  411  concentrates suspect materials along the solvent front. This concentration makes the explosives tester  400  more sensitive because by concentrating any explosives particles along the solvent front a larger amount of materials in one place. The color that will be produced by the reagents from ampoule A  408 , ampoule B  409 , and/or ampoule C  410  will be easier to see.  
         [0049]     The inspection tester  400  is fast, extremely sensitive, low-cost, very easy to implement, and provides a very low rate of false positives. The inspection tester for explosives  400  provides a fast, sensitive, low-cost, very easy to implement system for testing the suspected packages. The inspection tester for explosives  400  is inexpensive and disposable. The inspection tester for explosives  400  has detection limits between 0.1 to 100 nanograms, depending on the type of explosives present. A large number of common military and industrial explosives can be easily detected such as HMX, RDX, NG, TATB, Tetryl, PETN, TNT, DNT, TNB, DNB and NC. The inspection tester  400  is small enough that a number of them can fit in a pocket or brief case.  
         [0050]     While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.