Abstract:
A method for calibrating a test instrument and a set of leads having proximal ends coupled with the test instrument is described. The method includes shorting the distal ends of the set of leads during calibration and zeroing the test instrument during the shorting. The shorting includes coupling an electrical conductor with at least two of the distal ends.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation application of U.S. patent application Ser. No. 12/749,290, filed Mar. 29, 2010, which is a divisional application of U.S. patent application Ser. No. 12/194,187, filed Aug. 19, 2008, which is hereby incorporated in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to test instruments. More particularly, the present disclosure relates to the use of a zeroing apparatus to short together a plurality of leads. 
     BACKGROUND 
     A multimeter is an electronic measuring instrument that may combine in one unit a number of functions including the ability to measure voltage, current and resistance. Typically, a multimeter can perform these functions to a very high degree of accuracy. Accordingly, multimeters are typically used to diagnose or evaluate electrical devices such as batteries, motor controls, appliances, power supplies, and wiring systems. 
     To measure continuity or loop/line impedance accurately, a multimeter is typically calibrated or “zeroed” prior to making a measurement. Insofar as the resistance of the test leads that are used with the multimeter can impact accuracy, zeroing is typically performed by shorting together the distal ends of the leads, i.e., electrically coupling together those ends of the leads that are not plugged into the multimeter. 
     The distal ends of leads typically have many different arrangements. For example, conventional leads may be arranged with relatively independent distal ends that may include probe tips, alligator clips, sockets, or other lead ends. The distal ends also may be relatively positioned in a fixed pattern, e.g., so as to mimic appliance and device plugs that get connected to a power source via a wall socket. Given that a large number of options are available for the arrangement of the distal ends, the potential for incompletely shorting together the distal ends is also large. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of an unloaded configuration of an apparatus for shorting together a plurality of leads according to an embodiment of the present disclosure. 
         FIG. 2  is a front elevation view of the apparatus shown in  FIG. 1 . 
         FIG. 3  is a side elevation view of the apparatus shown in  FIG. 1 . 
         FIG. 4  is a first perspective view of the apparatus shown in  FIG. 1 . 
         FIG. 5  is a second perspective view of the apparatus shown in  FIG. 1 . 
         FIG. 6  is a top view illustrating a loaded configuration of the apparatus shown in  FIG. 1 . 
         FIGS. 7A-7C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a first mains cord. 
         FIGS. 8A-8C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a second mains cord. 
         FIGS. 9A-9C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a third mains cord. 
         FIGS. 10A-10C  illustrate an intermediate configuration of the apparatus of shown in  FIG. 1  with respect to a fourth mains cord. 
         FIGS. 11A-11C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a fifth mains cord. 
         FIGS. 12A-12C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a sixth mains cord. 
         FIGS. 13A-13C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a seventh mains cord. 
         FIG. 14  illustrates a method according to an embodiment of the present disclosure for shorting together the distal ends of the seventh mains cord shown in  FIGS. 13A-13C . 
         FIG. 15  illustrates a method according to an embodiment of the present disclosure for shorting together independent test probes the distal ends of test leads. 
         FIG. 16  illustrates a method according to an embodiment of the present disclosure for shorting together distal ends of independent test leads. 
     
    
    
     DETAILED DESCRIPTION 
     Specific details of embodiments according to the present disclosure are described below with reference to a zeroing apparatus and methods for shorting together multimeter leads. According to embodiments of the present disclosure, multimeters can be used to measure voltage, current, resistance, temperature, or other parameters. 
     The term “coupled” can include various types of relationships between two or more components or features. Further, the phrase “electrically coupled” can include a path conductively linking two or more components or features or the phrase “mechanically coupled” may encompass a physical association or structural linking of two or more components or features. Moreover, several other embodiments of the disclosure can have configurations, components, features or procedures different than those described in this section. A person of ordinary skill in the art, therefore, will accordingly understand that the disclosure may have other embodiments with additional elements, or the disclosure may have other embodiments without several of the elements shown and described below with reference to  FIGS. 1-15 . 
       FIGS. 1-5  show an apparatus  100  according to an embodiment of the present disclosure. The apparatus  100  can short together a plurality of leads, for example, when zeroing a multimeter (not shown in  FIGS. 1-5 ). The apparatus  100  as shown in  FIGS. 1-5  is in an “unloaded configuration,” which is the nominal state following its manufacture. 
     The apparatus  100  can include an electrically conductive strip that extends between first and second ends  102   a  and  102   b . The apparatus  100  includes a first surface  104   a  and a second surface  104   b  that faces away from the first surface  104   a . The apparatus  100  further includes a first edge  106  that is spaced from a second edge  108 . The first and second edges  106  and  108  couple the first and second surfaces  104   a  and  104   b  and extend between the and second ends  102   a  and  102   b . According to embodiments of the present disclosure, the electrically conductive strip can include a beryllium copper alloy substrate that is plated with sulphamate nickel. According to other embodiments of the present disclosure, the electrically conductive strip can include a stainless steel alloy or any other material that is electrically conductive, that can be plastically formed, and that can be elastically deformed between loaded and unloaded configurations for 3,000 or more cycles. 
     The apparatus includes a central bight  110  that is disposed between the first and second ends  102   a  and  102   b . The central bight  110  has a concave contour  112  that defines a portion of the first surface  104   a . The central bight  110  also defines an outward projecting central portion  116  of the first edge  106 . The central bight  110  can be sized and shaped to resiliently surround an upstanding lead, to facilitate at least in part the elastic deformation of the apparatus  100  between unloaded and loaded configurations, and to resiliently go into an annular lead. 
     A first bight  120  is disposed between the central bight  110  and the first end  102   a . The first bight  120  has a convex contour  122  that defines a portion of the first surface  104   a . Similarly, a second bight  130  is disposed between the central bight  110  and the second end  102   b . The second bight  130  has a convex contour  132  that also defines a portion of the first surface  104   a . A first contact segment  140  is disposed between the first bight  120  and the first end  102   a , and a second contact segment  150  is disposed between the second bight  130  and the second end  102   b . The first bight  120  and the first contact segment  140  define a first portion  106   a  of the first edge  106 , and the second bight  120  and the second contact segment  150  define a second portion  106   b  of the first edge  106 . 
     The first contact segment  140  includes a first leg  142  that projects outward from the second edge  108  and the second contact segment  150  includes a second leg  152  that similarly projects outward from the second edge  108 . The first leg  142  can include a first foot  144  and the second leg  152  includes a second foot  154 . The first and second feet  144  and  154  can perpendicularly project with respect to the first and second contact segments  140  and  150 , respectively. 
     A first grip segment  160  is disposed between the first contact segment  140  and the first end  102   a , and a second grip segment  170  is disposed the second contact segment  150  and between the second end  102   b . A first intermediate segment  180  is disposed between the first contact segment  140  and the first grip segment  160 , and a second intermediate segment  190  disposed between the second contact segment  150  and the second grip segment  170 . The first intermediate segment  180  and the first grip segment  160  further define the first portion  106   a  of the first edge  106  and the second intermediate segment  190 , and the second grip segment  170  second portion further define the second portion  106   b  of the first edge  106 . According to embodiments of the present disclosure, the first and second intermediate segments  180  and  190  can include a ridge, hole, or other formation to which alligator clips of independent leads may be attached so as to avoid slippage of the alligator clips&#39; jaws. 
     A first receptacle  200  is disposed at the first end  102   a  and includes concave contour  202  that defines a portion of the first surface  104   a . A second receptacle  210  is disposed at the second end  102   b  and includes a concave contour  212  that also defines a portion of the first face  104   a . The first receptacle  200  defines a first end portion  206  of the first edge  106  and the second receptacle  210  defines a second end portion  216  of the first edge  106 . The first and second end portions  206  and  216  project outward from the first and second portions  106   a  and  106   b , respectively, of the first edge  106 . According to embodiments of the present disclosure, the first and second receptacles  200  and  210  can be sized and shaped to resiliently receive and short together test probes of independent leads. 
     Thus, according to the embodiment of the present disclosure shown in  FIGS. 1-5 , the central bight  110  is contiguously coupled to the first and second bights  120  and  130 . The first bight  110  is contiguously coupled to the first contact segment  140 , the first grip segment  160  is contiguously coupled to the first receptacle  200 , and the first intermediate segment  180  contiguously couples the first contact segment  140  to the first grip segment  160 . Similarly, the second bight  130  is contiguously coupled to the second contact segment  150 , the second grip segment  170  is contiguously coupled to the second receptacle  210 , and the second intermediate segment  190  contiguously couples the second contact segment  150  to the second grip segment  170 . Additionally, the first face  104   a  is partially defined by the concave contour  112  of the central bight  110 , the convex contours  122  and  132  of the first and second bights  120  and  130 , and the concave contours  202  and  212  of the first and second receptacles  200  and  210 . 
     With particular reference to  FIG. 1 , the first intermediate segment  180  is angularly oriented with respect to the first contact segment  140  and with respect to the first grip segment  160 . For example, the intermediate segment  180  can be orthogonally disposed with respect to the first grip segment  160  and can be obliquely disposed with respect to the first contact segment  140 . Of course, there can be different relative angles of the intermediate segments  180  with respect to the first contact segment  140  and with respect to the first grip segment  160 . The second intermediate segment  190  is also angularly oriented with respect to the second contact segment  150  and the second grip segment  170 . As shown in the  FIG. 1  embodiment, the first intermediate segment  180  is contiguously coupled to the first contact segment  140  by a convex contour  182   a  that defines a portion of the first surface  104   a  and is contiguously coupled to the first grip segment  160  by a concave contour  182   b  that also defines a portion of the first surface  104   a . Similarly, the second intermediate segment  190  is contiguously coupled to the second contact segment  150  by a convex contour  192   a  that defines a portion of the first surface  104   a  and is contiguously coupled to the second grip segment  170  by a concave contour  192   b  that defines a portion of the first surface  104   a.    
       FIG. 6  shows the “loaded” configuration of the apparatus  100 . In the present disclosure, the term “load” can refer to storing of potential energy. For example, a compressive force, such as that indicated with arrows P, elastically deforms the apparatus  100  by displacing the first and second receptacles  200  and  210  toward one another, thereby loading the apparatus  100 . A partial release of the stored potential energy is referred to in the present disclosure as an “intermediate” configuration. 
       FIGS. 7A-7C  illustrate an intermediate configuration of the apparatus shown in  FIG. 1  with respect to a first mains cord  300 . As it is used in the present disclosure, a “mains cord” refers to a plurality of leads that are fixed in a pattern. For example,  FIGS. 7A and 7B  respectively show elevation and end views of three leads arranged in a pattern that mimics a wall socket that is typically used in the United States.  FIG. 7C  is an end view similar to  FIG. 7B  that shows an intermediate configuration of the apparatus  100  that is disposed, e.g., intermingled amongst the leads, in the first mains cord  300  pattern such that the three leads are shorted together. In particular, the apparatus  100  is resiliently biased against each of the three leads and provides an electrical conductor that shorts the leads together. 
     Different mains cords can have different lead patterns.  FIGS. 8A and 8B  respectively show elevation and end views of a second mains cord  310  including three leads arranged in a pattern that mimics a wall socket that is typically used in Australia.  FIG. 8C  shows an intermediate configuration of the apparatus  100  disposed in the second mains cord  310  pattern such that the three leads are shorted together.  FIGS. 9A and 9B  respectively show elevation and end views of a third mains cord  320  including three leads arranged in a pattern that mimics a wall socket that is typically used in Denmark.  FIG. 9C  shows an intermediate configuration of the apparatus  100  disposed in the third mains cord  320  pattern such that the three leads are shorted together.  FIGS. 10A and 10B  respectively show elevation and end views of a fourth mains cord  330  including three leads arranged in a pattern that mimics a wall socket that is typically used in the United Kingdom.  FIG. 10C  shows an intermediate configuration of the apparatus  100  disposed in the fourth mains cord  330  pattern such that the three leads are shorted together.  FIGS. 11A and 11B  respectively show elevation and end views of a fifth mains cord  340  including three leads arranged in a pattern that mimics a wall socket that is typically used in Switzerland.  FIG. 11C  shows an intermediate configuration of the apparatus  100  disposed in the fifth mains cord  340  pattern such that the three leads are shorted together.  FIGS. 12A and 12B  respectively show elevation and end views of a sixth mains cord  350  including three leads arranged in a pattern that mimics a wall socket that is typically used in Italy.  FIG. 12C  shows an intermediate configuration of the apparatus  100  disposed in the sixth mains cord  350  pattern such that the three leads are shorted together.  FIGS. 13A and 13B  respectively show elevation and end views of a seventh mains cord  360  including three leads arranged in a pattern that mimics a wall socket that is typically used in Europe.  FIG. 13C  shows an intermediate configuration of the apparatus  100  disposed in the seventh mains cord  360  pattern such that the three leads are shorted together. 
     With respect to  FIGS. 13B and 13C , the central portion  116  of the central bight  110  extends into and resiliently engages an annular lead, and the first and second feet  144  and  154  can be subsequently grasped to pull the apparatus away from the seventh mains cord  360 . According to embodiments in which the apparatus is oriented such that the central portion  116  projects away from a mains cord, the first and second legs  152  and  154  project toward the mains cord. The projection of the first and second legs  152  and  154  from the second edge  108  is selected such that the first and second feet  144  and  154  can displace a safety sheath (not shown) that surrounds one or more of the leads or can maintain the apparatus  100  at a pre-selected distance away from the body of the mains cord such that the apparatus engages electrically conductive portions of the leads. 
       FIG. 14  illustrates a method according to an embodiment of the present disclosure for shorting together the distal ends of the seventh mains cord  360  shown in  FIGS. 13A-13C . An electrical conductor, e.g., apparatus  100 , is formed in an unloaded configuration. According to embodiments of the present disclosure, the forming can include plastically forming, e.g., punching, stamping, pressing, casting and/or other manufacturing operations, a substrate of beryllium copper that is plated with sulphamate nickel. The electrical conductor is elastically deformed from the unloaded configuration to a loaded configuration in which potential energy is stored. The electrical conductor is then disposed in a pattern of leads and permitted to resiliently assume an intermediate configuration at a potential energy level between the unloaded and loaded configurations. The electrical conductor in the intermediate configuration contiguously engages all three leads concurrently. As shown in  FIG. 14 , disposing the electrical conductor can include inserting a projection of the electrical conductor into a recess defined by one of the three leads. The opposite ends of the mains cord  360  can be electrically coupled to a multimeter  400  and a zeroing operation performed by the multimeter  400 . 
       FIG. 15  illustrates another method according to an embodiment of the present disclosure for shorting together the distal ends of test leads. As compared to  FIG. 14 , a set of test leads  370  include independent test probes that are not relatively fixed in a pattern. The distal ends of the test leads  370  can be resiliently received in the first and second receptacles  200  and  210  and are shorted together by the electrical conductor. 
     Specific details of the embodiments of the present disclosure are set forth in the description and in the figures to provide a thorough understanding of these embodiments. A person skilled in the art, however, will understand that the invention may be practiced without several of these details or additional details can be added to the invention. Well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present disclosure. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of including, but not limited to. Additionally, the words “herein”, “above”, “below”, and words of similar connotation, when used in the present disclosure, shall refer to the present disclosure as a whole and not to any particular portions of the present disclosure. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. 
     The above detailed description of embodiments is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. 
     The teachings of the present disclosure provided herein can be applied to systems other than the analysis systems described above. The features of the various embodiments described above can be combined or altered to provide further embodiments. 
     These and other changes can be made to the invention in light of the above Detailed Description. While the above description describes certain embodiments of the invention, and describes the best mode contemplated, no matter how detailed the above appears in text, the invention can be practiced in many ways. Details of the embodiments in the present disclosure may vary considerably in their implementation details, while still being encompassed by the invention disclosed herein. 
     The terminology used in the Detailed Description is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments according to the present disclosure. Certain terms may even be emphasized; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. In general, the terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the present disclosure, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the invention encompasses not only the embodiments disclosed in the present disclosure, but also all equivalent ways of practicing or implementing the invention under the claims. 
     While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate the various aspects of the invention in any number of claim forms. Accordingly, the inventors reserve the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention.