Test lead, measuring instrument, and measuring unit

Abstract

A test lead (1) comprises a sense-side plug (2) having a high-side sense terminal (4H) and a low-side sense terminal (4L), a source-side plug (3) having a high-side source terminal (6H) and a low-side source terminal (6L), a high-side contact portion (8H) including a high-side contact (9H) for contacting an object being measured, a low-side contact portion (8L) including a low-side contact (9L) for contacting the object being measured, and a wiring portion (11) including first wiring (12) that connects the high-side sense terminal and the high-side contact, second wiring (13) that connects the high-side source terminal and the high-side contact, third wiring (14) that connects the low-side sense terminal and the low-side contact, and fourth wiring (15) that connects the low-side source terminal and the low-side contact, wherein the appearance of the high-side sense terminal and the appearance of the low-side sense terminal differ from one another, and the appearance of the high-side source terminal and the appearance of the low-side source terminal differ from one another.

Description

Test leads, measuring instruments, and measuring units

[0001] The present invention relates to a test lead, a measuring instrument, and a measuring unit, and more particularly to a test lead for electrically connecting a measuring instrument and an object to be measured, a measuring instrument to which the test lead is connected, and a measuring unit including the test lead and the measuring instrument.

[0002] Generally, when measuring the electrical characteristics of a device under test (hereinafter also referred to as a DUT), a test lead is used to electrically connect the measuring instrument and the DUT.

[0003] For example, Patent Document 1 discloses a four-pin test lead compatible with measuring electrical characteristics using a four-terminal measurement method. Generally, a test lead compatible with measuring electrical characteristics using a four-terminal measurement method includes high-side and low-side source terminals for applying a DC or AC measurement signal (voltage or current) to a DUT, and high-side and low-side sense terminals for detecting a voltage drop across the DUT when the measurement signal is applied to the DUT.

[0004] For example, when measuring the resistance of a DUT using the above-mentioned four-pin test lead, the high-side source terminal and high-side sense terminal are connected to one end of the DUT, and the low-side source terminal and low-side sense terminal are connected to the other end of the DUT. The measuring instrument then supplies a measurement signal from the high-side source terminal to the low-side source terminal via the DUT, and detects the voltage between the high-side sense terminal and low-side sense terminal (the voltage across the DUT) and the current flowing through the DUT, thereby enabling measurement of the resistance of the DUT using the four-terminal measurement method.

[0005] U.S. Pat. No. 5,508,621

[0006] The inventors of the present invention have considered developing a new four-pin test lead.

[0007] Fig. 11 is a diagram showing a four-pin test lead that the inventors of the present application investigated prior to filing this application. For ease of explanation, Fig. 11 shows only the terminal of the test lead that connects to the measuring instrument.

[0008] As shown in FIG. 11 , the test lead 90 includes a two-pin plug with two high-side terminals paired together and a two-pin plug with two low-side terminals paired together. Specifically, in the test lead 90, a high-side source terminal 93H and a high-side sense terminal 94H form a paired two-pin plug 91H, and a low-side source terminal 93L and a low-side sense terminal 94L form a paired two-pin plug 91L. Furthermore, the end of the test lead 90 opposite the two-pin plug 91H and the two-pin plug 91L is provided with a high-side contact portion and a low-side contact portion (not shown) for contacting the DUT. Specifically, the high-side contact portion of the test lead 90 has two portions, one of which is connected to the high-side source terminal 93H and the other of which is connected to the high-side sense terminal 94H. Similarly, the low-side contact portion has two portions, one of which is connected to the low-side source terminal 93L and the other of which is connected to the low-side sense terminal 94L.

[0009] Here, a case will be described in which the resistance value of a DUT is measured by a four-terminal measurement method using a test lead 90 shown in FIG.

[0010] First, the two-pin plugs 91H and 91L of the test leads 90 are inserted into the terminals of the measuring instrument. Next, the high-side contact and low-side contact (not shown) on the opposite side of the two-pin plugs 91H and 91L of the test leads 90 are in contact with two points (usually both ends) of the DUT. The measuring instrument then outputs an AC measurement signal and applies it to the DUT. This causes an AC current to flow between the high-side source terminal and the low-side source terminal through the DUT. At this time, as shown in FIG. 7 , a loop is formed by the wire 95H extending from the high-side two-pin plug 91H and the wire 95L extending from the low-side two-pin plug 91L, and this loop functions as a coil.

[0011] When performing AC measurements using test lead 90 in this way, if metal (conductor) comes close to one or both of the two-pin plugs 91H and 91L of test lead 90, eddy currents will be generated in the metal, causing measurement errors. Specifically, when AC current flows through the coil (loop) passing through wiring 95H (or 95L), a magnetic field will be generated that penetrates the coil. If metal is placed close to or around the coil, the magnetic field generated by the coil will generate eddy currents on the metal's surface. These eddy currents will further generate a magnetic field, generating an induced current in the loop. This induced current may cause measurement errors in the measuring instrument.

[0012] Therefore, the inventors of the present application considered changing the combination of terminals that make up the two-pin plug of a test lead in order to suppress the reduction in measurement errors caused by eddy currents. That is, they considered developing a test lead with a configuration that can suppress the generation of eddy currents. Specifically, they developed an improved test lead that includes a two-pin plug with a pair of two source terminals, one for the high side and one for the low side, and a two-pin plug with a pair of two sense terminals, one for the high side and one for the low side. They found that this improved test lead generates almost no eddy currents.

[0013] However, it has become clear that this improved test lead has the following problem. Specifically, each of the two-pin plugs of the improved test lead has a high terminal and a low terminal. Therefore, when connecting the test lead to a measuring instrument, it has become clear that there is a problem in that the user is more likely to make an incorrect connection than with a conventional test lead that has a two-pin plug with only the high terminals combined and a two-pin plug with only the low terminals combined. For example, there is a possibility that the user may mistakenly connect the high terminal of the improved test lead to the low input terminal of the measuring instrument, or the low terminal of the test lead to the high input terminal of the measuring instrument.

[0014] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a test lead that can suppress the generation of eddy currents while reducing the occurrence of incorrect connection to a measuring instrument by a user.

[0015] A test lead according to a representative embodiment of the present invention comprises a sense-side plug having a high-side sense terminal and a low-side sense terminal, a source-side plug having a high-side source terminal and a low-side source terminal, a high-side contact portion including a high-side contactor for contacting an object to be measured, a low-side contact portion including a low-side contactor for contacting the object to be measured, and a wiring portion including a first wire connecting the high-side sense terminal and the high-side contactor, a second wire connecting the high-side source terminal and the high-side contactor, a third wire connecting the low-side sense terminal and the low-side contactor, and a fourth wire connecting the low-side source terminal and the low-side contactor, wherein the high-side sense terminal and the low-side sense terminal have mutually different appearances, and the high-side source terminal and the low-side source terminal have mutually different appearances.

[0016] The test lead according to the present invention can suppress the generation of eddy currents and reduce the occurrence of incorrect connections to measuring instruments by users.

[0017] FIG. 2 is a diagram schematically illustrating the configuration of a test lead according to an embodiment of the present invention. FIG. 3 is a diagram schematically illustrating the configuration of a sense side plug of the test lead shown in FIG. 1. FIG. 4 is a diagram schematically illustrating the configuration of a sense side plug of the test lead shown in FIG. 1. FIG. 5 is a diagram schematically illustrating the configuration of a sense side plug of the test lead shown in FIG. 1. FIG. 6 is a diagram schematically illustrating the configuration of a source side plug of the test lead shown in FIG. 1. FIG. 7 is a diagram schematically illustrating the configuration of a source side plug of the test lead shown in FIG. 1. FIG. 8 is a diagram schematically illustrating the configuration of a source side plug of the test lead shown in FIG. 1. FIG. 9 is a diagram schematically illustrating the configuration of a source side plug of the test lead shown in FIG. 1. FIG. 10 is a diagram schematically illustrating the appearance of a measuring instrument according to an embodiment. FIG. 11 is a diagram schematically illustrating the appearance of a measurement unit according to an embodiment. FIG. 12 is a diagram for explaining a method of connecting the test lead shown in FIG. 1 to the measuring instrument. FIG. 13 is a diagram schematically illustrating the flow of current when measuring the electrical characteristics of a DUT by a four-terminal measurement method using the test lead shown in FIG. 1. FIG. 14 is a diagram schematically illustrating the configuration of a test lead according to another embodiment of the present invention. FIG. 15 is a diagram schematically illustrating the configuration of a test lead according to another embodiment of the present invention. Fig. 10 is a diagram schematically showing the configuration of a sense-side plug of the test lead shown in Fig. 9. Fig. 11 is a diagram schematically showing the configuration of a source-side plug of the test lead shown in Fig. 9. Fig. 12 is a diagram schematically showing a 4-pin test lead that the inventor of the present application studied prior to filing the present application.

[0018] 1. Overview of the Embodiments First, an overview of representative embodiments of the invention disclosed in this application will be described. Note that in the following description, as an example, reference numerals in the drawings corresponding to components of the invention are written in parentheses.

[0019] [1] A test lead (1) according to a representative embodiment of the present invention comprises a sense-side plug (2) having a high-side sense terminal (4H) and a low-side sense terminal (4L), a source-side plug (3) having a high-side source terminal (6H) and a low-side source terminal (6L), a high-side contact portion (8H) including a high-side contactor (9H) for contacting an object to be measured, a low-side contact portion (8L) including a low-side contactor (9L) for contacting the object to be measured, and a contact between the high-side sense terminal and the high-side contactor (9L). The high-side sense terminal and the low-side sense terminal have different appearances, and the high-side source terminal and the low-side source terminal have different appearances.

[0020] [2] In the test lead described in [1] above, the high-side sense terminal and the low-side sense terminal may have a surface color different from each other, and the high-side source terminal and the low-side source terminal may have a surface color different from each other.

[0021] [3] In the test lead described in [1] above, the high-side sense terminal and the low-side sense terminal may have different shapes or dimensions, and the high-side source terminal and the low-side source terminal may have different shapes or dimensions.

[0022] [4] In the test lead described in [2] or [3] above, the high-side sense terminal, the low-side sense terminal, the high-side source terminal, and the low-side source terminal may each be formed in a male shape, the sense-side plug may support one end of the high-side sense terminal and may further have a sense-side main body (5) that supports one end of the low-side sense terminal, the source-side plug may support one end of the high-side source terminal and may further have a source-side main body (7) that supports one end of the low-side source terminal, and a first display section (57) of the same color as the surface of the high-side sense terminal may be formed in an area on the high-side sense terminal side of the surface of the sense-side main body, and a second display section (77) of the same color as the surface of the high-side source terminal may be formed in an area on the high-side source terminal side of the surface of the source-side main body.

[0023] [5] In the test lead described in [4] above, the high-side sense terminal, the low-side sense terminal, the high-side source terminal, and the low-side source terminal each have a rod-shaped metal terminal (40H, 40L, 60H, 60L) and a cylindrical cover member (41H, 41L, 61H, 61L) that is coaxial with the metal terminal and covers the periphery of the metal terminal, the cover member of the high-side sense terminal and the sense-side main body part have a surface color different from each other, the cover member of the high-side source terminal and the source-side main body part have a surface color different from each other, the sense-side main body part holds the cover member of the high-side sense terminal in a state where one end side of the cover member of the high-side sense terminal is inserted into the sense-side main body part, and the source-side main body part holds the cover member of the high-side sense terminal in a state where one end side of the cover member of the high-side source terminal is inserted into the source-side main body part. the cover member of the high-side source terminal is held in the inserted state, a first opening (51) is formed in a region of the sense-side main body that overlaps with one end of the cover member of the inserted high-side sense terminal when viewed from a direction intersecting with the direction in which the cover member of the high-side sense terminal extends, and a second opening (71) is formed in a region of the source-side main body that overlaps with one end of the cover member of the inserted high-side source terminal when viewed from a direction intersecting with the direction in which the cover member of the high-side source terminal extends, the first display unit may be formed by the first opening and a part (410) of the cover member of the high-side sense terminal that is visible from the first opening, and the second display unit may be formed by the second opening and a part (610) of the cover member of the high-side source terminal that is visible from the second opening.

[0024] [6] In the test lead described in [5] above, the sense side body portion and the source side body portion are each formed in a rectangular parallelepiped shape, the sense side body portion has a first main surface (50a), a first back surface (50b) opposite to the first main surface, a first top surface (50c) that intersects the first main surface and the first back surface and from which the high-side sense terminal and the low-side sense terminal are arranged to protrude, a first bottom surface (50d) opposite to the first top surface and through which the first wiring and the second wiring are inserted, and two first side surfaces (50e, 50f) that intersect the first main surface, the first back surface, the first top surface, and the first bottom surface, The semiconductor device may have a second back surface (70b) opposite to the second main surface, a second top surface (70c) that intersects the second main surface and the second back surface and has the high-side source terminal and the low-side source terminal protruding therefrom, a second bottom surface (70d) opposite to the second top surface and through which the third wiring and the fourth wiring are inserted, and two second side surfaces (70e, 70f) that intersect the second main surface, the second back surface, the second top surface, and the second bottom surface, and the first opening may be formed in at least one of the first main surface and the first back surface in the sense side body portion, and the second opening may be formed in at least one of the second main surface and the second back surface in the source side body portion.

[0025] [7] In the test lead described in [6] above, the two first side surfaces may be formed in arc shapes recessed in the direction facing each other, and the two second side surfaces may be formed in arc shapes recessed in the direction facing each other.

[0026] [8] In the test lead according to [6] or [7] above, when viewed from a direction perpendicular to the first main surface side, an imaginary line that passes through the center of the sense side main body portion and is parallel to the direction in which the high-side sense terminal extends is defined as a first center line, and when viewed from a direction perpendicular to the second main surface side, an imaginary line that passes through the center of the source side main body portion and is parallel to the direction in which the high-side source terminal extends is defined as a second center line, A distance (L1) from the second center line to the end (54a) on the first top surface side of one of the first side surfaces is longer than a distance (L2) from the first side surfaces to the end (54b) on the first bottom surface side of the two first side surfaces, and when viewed from a direction perpendicular to the second main surface, a distance (L3) from the second center line to the end (74a) on the second top surface side of the two second side surfaces of the source side main body portion may be longer than a distance (L4) from the second center line to the end (74b) on the second bottom surface side of the two second side surfaces.

[0027] [9] In the test lead described in any one of [6] to [8] above, a predetermined mark (53) may be formed on the surface of the sense side main body portion or the surface of the source side main body portion.

[0028]

[10] In the test lead described in [9] above, the predetermined mark may be formed on the first upper surface of the sense side main body portion or the second upper surface of the source side main body portion.

[0029]

[11] An apparatus according to one embodiment of the present invention is a measuring instrument (200) for measuring electrical characteristics of an object to be measured. The measuring instrument comprises a measuring unit (207) that generates a measurement signal to be applied to the object to be measured and measures the electrical characteristics of the object to be measured based on a detection signal when the measurement signal is applied to the object to be measured, a measuring instrument main body (201) including a housing (205) that houses the measurement unit, a high-side output terminal (210H) and a low-side output terminal (210L) that are arranged on one surface of the housing and output the measurement signal, and a high-side input terminal (211H) and a low-side input terminal (211L) that are arranged on the one surface of the housing and input the detection signal, and a first guide frame (221) that is formed on the one surface so as to surround the high-side output terminal and the low-side output terminal, and a second guide frame (222) that is formed so as to surround the high-side input terminal and the low-side input terminal.

[0030]

[12] A measurement unit (300) according to one embodiment of the present invention comprises the test lead (1) described in any one of [1] to

[10] above and the measurement instrument (200) described in

[11] above, and is characterized in that the high-side sense terminal is configured to be connectable to the high-side input terminal, the low-side sense terminal is configured to be connectable to the low-side input terminal, the high-side source terminal is configured to be connectable to the high-side output terminal, and the low-side source terminal is configured to be connectable to the low-side output terminal.

[0031] 2. Specific Examples of Embodiments Specific examples of embodiments of the present invention will be described below with reference to the drawings. In the following description, components common to the embodiments will be designated by the same reference numerals, and repeated description will be omitted.

[0032] FIG. 1 is a diagram schematically illustrating the configuration of a test lead 1 according to an embodiment.

[0033] FIG. 1 shows a case where test lead 1 is arranged on the XY plane so that test lead 1 extends along the Z axis in a three-dimensional Cartesian coordinate system consisting of the X axis, Y axis, and Z axis.

[0034] The test lead 1 is a device for electrically connecting a measuring instrument and a device under test (DUT). For example, the test lead 1 is a four-pin lead that is compatible with measuring electrical characteristics using a four-terminal measurement method.

[0035] Examples of the measuring instrument include an LCR meter, an ohm meter, a battery tester, etc. that measure electrical characteristics such as the impedance of the DUT. Details of the measuring instrument (measuring instrument 200) will be described later.

[0036] As shown in FIG. 1 , the test lead 1 includes a high-side sense terminal 4H, a low-side sense terminal 4L, a high-side source terminal 6H, a low-side source terminal 6L, a high-side contact portion 8H, a low-side contact portion 8L, and a wiring portion 11.

[0037] The high-side sense terminal 4H, the low-side sense terminal 4L, the high-side source terminal 6H, and the low-side source terminal 6L are terminals for electrically connecting the test lead to a measuring instrument. The high-side sense terminal 4H, the low-side sense terminal 4L, the high-side source terminal 6H, and the low-side source terminal 6L are each formed in a male shape. For example, the test lead 1 can be electrically connected to the measuring instrument by inserting the high-side sense terminal 4H, the low-side sense terminal 4L, the high-side source terminal 6H, and the low-side source terminal 6L into female connectors formed on the measuring instrument.

[0038] The high-side sense terminal 4H and the low-side sense terminal 4L are integrally formed as a pair of two-pin plugs. Similarly, the high-side source terminal 6H and the low-side source terminal 6L are integrally formed as a pair of two-pin plugs. In this embodiment, the two-pin plug having the high-side sense terminal 4H and the low-side sense terminal 4L is referred to as the "sense-side plug 2," and the two-pin plug having the high-side source terminal 6H and the low-side source terminal 6L is referred to as the "source-side plug 3."

[0039] The sense side plug 2 includes a high side sense terminal 4H, a low side sense terminal 4L, and a sense side main body 5. The sense side main body 5 supports the high side sense terminal 4H and the low side sense terminal 4L. Specifically, the sense side main body 5 supports one end of the high side sense terminal 4H and one end of the low side sense terminal 4L. The high side sense terminal 4H and the low side sense terminal 4L are spaced apart and arranged to protrude from the sense side main body 5.

[0040] The high-side sense terminal 4H and the low-side sense terminal 4L have different appearances. For example, the surface color of the high-side sense terminal 4H and the surface color of the low-side sense terminal 4L are different from each other. Furthermore, a first indicator 57 of the same color as the surface of the high-side sense terminal 4H is formed in an area on the surface of the sense-side main body 5 on the high-side sense terminal 4H side. The high-side sense terminal 4H, the low-side sense terminal 4L, and the first indicator 57 will be described in detail below.

[0041] The source-side plug 3 includes a high-side source terminal 6H, a low-side source terminal 6L, and a source-side body portion 7. The source-side body portion 7 supports the high-side source terminal 6H and the low-side source terminal 6L. Specifically, the source-side body portion 7 supports one end of the high-side source terminal 6H and one end of the low-side source terminal 6L. The high-side source terminal 6H and the low-side source terminal 6L are spaced apart from each other and arranged to protrude from the source-side body portion 7.

[0042] The high-side source terminal 6H and the low-side source terminal 6L have different appearances. For example, the surface colors of the high-side source terminal and the low-side source terminal are different from each other. Furthermore, a second display portion 77 of the same color as the surface of the high-side source terminal 6H is formed in the area on the high-side source terminal 6H side of the surface of the source-side main body portion 7. The high-side source terminal 6H, the low-side source terminal 6L, and the second display portion 77 will be described in detail later.

[0043] Test lead 1 is configured to be connectable to measuring instrument 200, which will be described later. As will be described in detail later, high-side sense terminal 4H is configured to be connectable to high-side input terminal 211H of measuring instrument 200, low-side sense terminal 4L is configured to be connectable to low-side input terminal 211L, high-side source terminal 6H is configured to be connectable to high-side output terminal 210H, and low-side source terminal 6L is configured to be connectable to low-side output terminal 210L.

[0044] The sense side main body portion 5 and the source side main body portion 7 also function as handles (gripping portions) for the test lead 1 when the user connects (inserts) the high side sense terminal 4H, the low side sense terminal 4L, the high side source terminal 6H, and the low side source terminal 6L to the terminals of the measuring instrument.

[0045] A first wire 12 is connected to the high-side sense terminal 4H, and a third wire 14 is connected to the low-side sense terminal 4L. The first wire 12 connects the high-side sense terminal 4H and the high-side contactor 9H. The third wire 14 connects the low-side sense terminal 4L and the low-side contactor 9L.

[0046] A second wiring 13 is connected to the high-side source terminal 6H, and a fourth wiring 15 is connected to the low-side source terminal 6L. The second wiring 13 is a wiring that connects the high-side source terminal 6H and the high-side contactor 9H. The fourth wiring 15 is a wiring that connects the low-side source terminal 6L and the low-side contactor 9L.

[0047] The first wiring 12 and a portion of the third wiring 14 are routed while being housed within the sense side body 5. Specifically, one end of the first wiring 12 is connected to the high side sense terminal 4H within the sense side body 5, and the other end of the first wiring 12 is drawn out from the inside of the sense side body 5 to the outside. One end of the third wiring 14 is connected to the low side sense terminal 4L within the sense side body 5, and the other end of the third wiring 14 is drawn out from the inside of the sense side body 5 to the outside.

[0048] The second wiring 13 and a portion of the fourth wiring 15 are routed while being housed within the source side body 7. Specifically, within the source side body 7, one end of the second wiring 13 is connected to the high side source terminal 6H, and the other end of the second wiring 13 is drawn out from the inside of the source side body 7 to the outside. Within the source side body 7, one end of the fourth wiring 15 is connected to the low side source terminal 6L, and the other end of the fourth wiring 15 is drawn out from the inside of the source side body 7 to the outside. The detailed configurations of the sense side plug 2 and the source side plug 3 will be described later.

[0049] The wiring portion 11 is a functional portion for routing the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 together as a wiring group between the sense-side plug 2 and the source-side plug 3 and the high-side contact 8H and the low-side contact 8L. As shown in FIG. 1 , the wiring portion 11 includes, for example, the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 and a routing portion 16.

[0050] Each of the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 includes a lead wire having a core wire made of metal and a coating made of an insulating material that covers the core wire. Note that each of the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 is not limited to a structure formed of only one lead wire, but may also have a structure in which multiple lead wires are connected in series via other metal materials such as a connector.

[0051] The first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 are connected to the sense side plug 2, the source side plug 3, the high side contact 9H, and the low side contact 9L by a known connection method such as crimp terminals or soldering.

[0052] The routing portion 16 accommodates, for example, the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 together, and branches off one end of each of the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 to lead to the sense-side plug 2 and the source-side plug 3, and branches off the other end of each of the first wiring 12, the second wiring 13, the third wiring 14, and the fourth wiring 15 to lead to the high-side contact 8H and the low-side contact 8L. The routing portion 16 is formed of an insulating material such as rubber or resin.

[0053] The high-side contact portion 8H and the low-side contact portion 8L are functional portions for contacting the DUT when measuring the electrical characteristics of the DUT. In this embodiment, the high-side contact portion 8H and the low-side contact portion 8L have, for example, a so-called probe-type shape.

[0054] The high-side contact portion 8H has a high-side contactor 9H for contacting the DUT and a gripping portion 10H for supporting the high-side contactor 9H and for the user to grip during measurement. The high-side contactor 9H includes, for example, two probes.

[0055] The gripping portion 10H is formed in a tubular (e.g., cylindrical) shape. Fig. 1 shows, as an example, a case in which the gripping portion 10H is arranged so that the axis of the gripping portion 10H is parallel to the Y-axis direction.

[0056] A first wiring 12 and a second wiring 13 are inserted inside the gripping portion 10H. Specifically, one end of the first wiring 12 is pulled out from inside the gripping portion 10H to one end in the axial direction of the gripping portion 10H (the positive side of the Y axis in FIG. 1 ) and connected to the high-side sense terminal 4H via a wiring portion 16. The other end of the first wiring 12 is connected to one of the probes constituting the high-side contactor 9H inside the gripping portion 10H. One end of the second wiring 13 is pulled out from inside the gripping portion 10H to one end in the axial direction of the gripping portion 10H and connected to the high-side source terminal 6H via a wiring portion 16. The other end of the second wiring 13 is connected to the other probe constituting the high-side contactor 9H inside the gripping portion 10H.

[0057] The low-side contact portion 8L has the same configuration as the high-side contact portion 8H. Specifically, the low-side contact portion 8L has a low-side contactor 9L for contacting the DUT and a gripping portion 10L that supports the low-side contactor 9L and is held by the user during measurement. The low-side contactor 9L includes two probes. The gripping portion 10L is cylindrical, similar to the gripping portion 10H.

[0058] A third wiring 14 and a fourth wiring 15 are inserted inside the gripping portion 10L. Specifically, one end of the third wiring 14 is pulled out from inside the gripping portion 10L to one end in the axial direction of the gripping portion 10L (the positive side of the Y axis in FIG. 1 ) and connected to the low-side sense terminal 4L via a wiring portion 16. The other end of the third wiring 14 is connected to one of the probes constituting the low-side contactor 9L inside the gripping portion 10L. One end of the fourth wiring 15 is pulled out from inside the gripping portion 10L to one end in the axial direction of the gripping portion 10L and connected to the low-side source terminal 6L via a wiring portion 16. The other end of the fourth wiring 15 is connected to the other probe constituting the low-side contactor 9L inside the gripping portion 10L.

[0059] The surface color of the high-side grip portion 10H and the surface color of the low-side grip portion 10L are preferably different from each other. Furthermore, the surface color of the grip portion 10H is preferably the same as or similar to the surface color of the high-side sense terminal 4H and the high-side source terminal 6H, which will be described later. For example, it is preferable that the surface of the high-side grip portion 10H is colored red, and the surface of the low-side grip portion 10H is colored a color other than red (for example, black).

[0060] Here, the configuration of the sense-side plug 2 will be described in detail.

[0061] 2A to 2D are diagrams schematically showing the configuration of the sense side plug 2 of the test lead 1 shown in Fig. 1. Fig. 2A shows a perspective view of the sense side plug 2, Fig. 2B shows a plan view of the sense side plug 2 seen from the main surface side, Fig. 2C shows a plan view of the sense side plug 2 seen from the top surface side, and Fig. 2D shows a plan view of the sense side plug 2 seen from the bottom surface side. Note that for convenience of illustration, parts of the first wiring 12 and the third wiring 14 are omitted from Figs. 2A to 2D.

[0062] 2A to 2D , the sense side body 5 is formed, for example, from an insulating material (e.g., resin). The sense side body 5 is formed, for example, in the shape of a rectangular parallelepiped and has six faces. The sense side body 5 can be formed, for example, by known injection molding techniques. Specifically, the sense side body 5 has a main surface 50a, a back surface 50b, a top surface 50c, a bottom surface 50d, and side surfaces 50e and 50f.

[0063] The main surface 50a is, for example, the surface with the largest area among the six surfaces constituting the sense side main body 5. The back surface 50b is the surface opposite to the main surface 50a. In this embodiment, as an example, as shown in FIG. 2B , the surface on the positive side in the Z axis direction is the main surface 50a, and the surface on the negative side in the Z axis direction is the back surface 50b. Note that in this embodiment, as an example, the main surface 50a and the back surface 50b have the same shape.

[0064] The top surface 50c intersects with the main surface 50a and the back surface 50b and is a surface on which the high-side sense terminal 4H and the low-side sense terminal 4L are protruding. The bottom surface 50d is opposite the top surface 50c and is a surface through which the first wiring 12 and the third wiring 14 are inserted. In the present embodiment, as an example, as shown in Figures 2C and 2D, the surface on the positive side in the Y-axis direction is the top surface 50c and the surface on the negative side in the Y-axis direction is the bottom surface 50d.

[0065] The side surface 50e and the side surface 50f are surfaces that intersect with the main surface 50a, the back surface 50b, the top surface 50c, and the bottom surface 50d. In the present embodiment, as an example, as shown in Figures 2B to 2D, the surface on the positive side in the X-axis direction is the side surface 50e, and the surface on the negative side in the X-axis direction is the side surface 50f.

[0066] 2A and 2C, the high-side sense terminal 4H and the low-side sense terminal 4L are formed to protrude from the upper surface 50c of the sense-side main body portion 5. For example, the high-side sense terminal 4H and the low-side sense terminal 4L protrude from the upper surface 50c in a direction perpendicular to the upper surface 50c (positive direction of the Y-axis).

[0067] 2C , the high-side sense terminal 4H includes a rod-shaped metal terminal 40H made of metal and a cover member 41H. The metal terminal 40H is fixed to the sense-side main body 5 in a state where it protrudes from the top surface 50c in a direction perpendicular to the top surface 50c (the positive direction of the Y axis). One axial end of the metal terminal 40H has a shape that allows it to be inserted into, for example, a female terminal of a measuring instrument (a high-side input terminal 211H of a measuring instrument 200, described below). The other axial end of the metal terminal 40H is fixed inside the sense-side main body 5 and is connected to the first wiring 12 by a crimp terminal, soldering, or the like.

[0068] The cover member 41H is formed, for example, from an insulating material (e.g., resin). As shown in FIG. 2C , the cover member 41H is formed in a cylindrical shape. For example, the cover member 41H is formed by a known injection molding technique. The inner diameter of the cover member 41H is larger than the maximum outer diameter of the rod-shaped metal terminal 40H. The cover member 41H is arranged to cover the periphery of the metal terminal 40H. That is, the cover member 41H is arranged coaxially with and spaced apart from the metal terminal 40H. One end of the cover member 41H, i.e., the end on the Y-axis direction negative side, is inserted into the sense side main body 5 and supported by the sense side main body 5.

[0069] Here, it is preferable that the color of the surface of the cover member 41H is different from the color of the surfaces (principal surface 50a and back surface 50b) of the sense side main body portion 5. For example, the cover member 41H is colored red, and the principal surface 50a and back surface 50b of the sense side main body portion 5 are colored black (a color other than red).

[0070] Like the high-side sense terminal 4H, the low-side sense terminal 4L includes a rod-shaped metal terminal 40L made of metal and a cover member 41L. The metal terminal 40L is fixed to the sense-side main body 5 in a state where it protrudes from the top surface 50c in a direction perpendicular to the top surface 50c (the positive direction of the Y axis). One end of the metal terminal 40L has a shape that allows it to be inserted into, for example, a female terminal of a measuring instrument (a low-side input terminal 211L of the measuring instrument 200, described below). The other end of the metal terminal 40L is fixed inside the sense-side main body 5 and is connected to the third wiring 14 by a crimp terminal, soldering, or the like.

[0071] The cover member 41L is formed into a cylindrical shape from an insulating material (e.g., resin). For example, the cover member 41L and the sense side main body 5 are integrally molded by known injection molding technology. The inner diameter of the cover member 41L is larger than the maximum outer diameter of the rod-shaped metal terminal 40L. The cover member 41L is arranged to cover the periphery of the metal terminal 40L. In other words, the cover member 41L is arranged coaxially with and spaced apart from the metal terminal 40L.

[0072] As with the high-side cover member 41H, the cover member 41L and the sense side main body 5 may be formed separately, and the end of the cover member 41L on the negative side of the Y axis direction may be inserted into the sense side main body 5 and fixed in place.

[0073] Furthermore, it is preferable that the color of the surface of the cover member 41L is the same as or similar to the color of the surface (principal surface 50a and back surface 50b) of the sense side main body portion 5. For example, the cover member 41L is colored black, and the principal surface 50a and back surface 50b of the sense side main body portion 5 are colored black.

[0074] As described above, the sense side main body 5 has a first display unit 57 formed therein. Specifically, the sense side main body 5 has an opening (through hole) 51 formed therein that allows a portion of the high-side sense terminal 4H inserted into the sense side main body 5 to be visible. For example, as shown in FIGS. 2A and 2B , the opening 51 is formed in a region of the sense side main body 5 that overlaps with one end of the inserted cover member 41H when viewed from a direction intersecting the direction in which the cover member 41H extends (e.g., the Z-axis direction). That is, the first display unit 57 is formed by the opening 51 and a portion 410 of the cover member 41H that is visible through the opening 51.

[0075] Here, the opening 51 is formed on at least one of the main surface 50 a and the back surface 50 b of the sense side main body 5. In the present embodiment, as an example, the opening 51 is formed on both the main surface 50 a and the back surface 50 b, so that a part of the inserted high-side sense terminal 4H of the sense side main body 5 is visible when looking at either the main surface 50 a or the back surface 50 b.

[0076] 2A , a portion of the high-side sense terminal 4H that is visible through the opening 51 may be formed to protrude outward from the opening 51. That is, a protrusion may be formed on the outer peripheral surface of the cover member 41H of the high-side sense terminal 4H that is formed in a cylindrical shape, and the protrusion may protrude outward from the opening 51 of the sense-side main body 5 when one end of the cover member 41H is inserted into the sense-side main body 5.

[0077] At least one of the main surface 50a, the back surface 50b, and the bottom surface 50d of the sense-side main body 5 may be provided with information (mark) indicating that it is a sense-side plug. For example, as shown in FIGS. 2A and 2B , a mark 55 indicating "SENSE" may be provided on the main surface 50a and the back surface 50b. Furthermore, an "H" mark indicating a high-side terminal and an "L" mark indicating a low-side terminal may be provided on both sides of the mark 55 in the X-axis direction.

[0078] A predetermined mark 53 may also be formed on the surface of the sense-side main body 5. The mark 53 indicates that the sense-side plug 2 is the “sense side.” For example, the mark 53 indicating the sense side is formed on at least one of the main surface 50a, the back surface 50b, the top surface 50c, the bottom surface 50d, and the two side surfaces 50e and 50f of the sense-side main body 5. For example, as shown in FIGS. 2A and 2D , the mark 53 is formed on the bottom surface 50d. Here, the mark 53 is preferably formed on the high-side sense terminal 4H side. The mark 53 is preferably the same shape as the mark (mark 240, described below) formed around the female connector of the meter. While not particularly limited, the mark 53 may be, for example, a geometric shape or a letter. FIG. 2D shows an example in which the mark 53 is polygonal (triangular).

[0079] Furthermore, sense side main body 5 may have a shape that facilitates insertion and removal of sense side plug 2 into and from a measuring instrument. Specifically, as shown in Figures 2A and 2B, two side surfaces 50e, 50f of sense side main body 5 are formed in arc shapes that are recessed in the directions facing each other.

[0080] 2A and 2B , when sense side main body 5 is viewed in a direction perpendicular to main surface 50 a (Z-axis direction), an imaginary line that passes through the center of sense side main body 5 and is parallel to the direction in which high-side sense terminal 4H extends (Y-axis direction) is defined as a first center line S1. In this case, when viewed in the direction perpendicular to main surface 50 a (Z-axis direction), it is preferable that a distance L1 from first center line S1 to end portions 54 a of two side surfaces 50 e, 50 f of sense side main body 5 on the top surface 50 c side is longer than a distance L2 from first center line S1 to end portions 54 b of two side surfaces 50 e, 50 f on the bottom surface 50 d side. In other words, when the direction away from the first center line S1 along the X-axis direction is defined as the height direction of the side surfaces 50e and 50f, the curvature of the two side surfaces 50e and 50f may be set so that the end portion 54a, which is the vertex of the two side surfaces 50e and 50f on the top surface 50c side, is higher than the end portion 54b, which is the vertex of the two side surfaces 50e and 50f on the bottom surface 50d side.

[0081] Furthermore, a plurality of protrusions 80 may be formed and spaced apart from each other on the two side surfaces 50 e, 50 f of the sense-side main body 5. For example, as shown in Fig. 2A, the protrusions 80 are formed to protrude from the side surfaces 50 e, 50 f in a direction perpendicular to the side surfaces 50 e, 50 f (the X-axis direction) and extend in the Z-axis direction. The plurality of protrusions 80 are formed and spaced apart from each other in the direction in which the high-side sense terminal 4H and the low-side sense terminal 4L extend (the Y-axis direction).

[0082] Next, the configuration of the source-side plug 3 will be described in detail.

[0083] 3A to 3D are diagrams schematically showing the configuration of the source-side plug 3 of the test lead 1 shown in Fig. 1. Fig. 3A shows a perspective view of the source-side plug 3, Fig. 3B shows a plan view of the source-side plug 3 seen from the main surface side, Fig. 3C shows a plan view of the source-side plug 3 seen from the top surface side, and Fig. 3D shows a plan view of the source-side plug 3 seen from the bottom surface side. Note that for convenience of illustration, part of the second wiring 13 and the fourth wiring 15 are omitted from Figs. 3A to 3D.

[0084] The source-side plug 3 differs in appearance from the sense-side plug 2 in that it does not have the mark 53, but in other respects it is similar to the sense-side plug 2. A specific description will be given below.

[0085] 3A to 3D , the source-side body 7 is formed into a rectangular parallelepiped shape from an insulating material (resin) by known injection molding technology, for example, similar to the sense-side body 5, and has six surfaces. Specifically, the source-side body 7 has a main surface 70 a, a back surface 70 b, a top surface 70 c, a bottom surface 70 d, and side surfaces 70 e and 70 f.

[0086] The main surface 70a is, for example, the surface with the largest area among the six surfaces constituting the source-side main body portion 7. The back surface 70b is the surface opposite the main surface 70a. In the present embodiment, as an example, as shown in FIG. 3B , the surface on the positive side in the Z-axis direction is the main surface 70a, and the surface on the negative side in the Z-axis direction is the back surface 70b. The top surface 70c intersects with the main surface 70a and the back surface 70b, and the high-side source terminal 6H and the low-side source terminal 6L are protruding and disposed thereon. The bottom surface 70d is opposite the top surface 70c, and is the surface through which the second wiring 13 and the fourth wiring 15 are inserted. In the present embodiment, as an example, as shown in FIGS. 3C and 3D , the surface on the positive side in the Y-axis direction is the top surface 70c, and the surface on the negative side in the Y-axis direction is the bottom surface 70d. The side surfaces 70e and 70f are surfaces that intersect with the main surface 70a, the back surface 70b, the top surface 70c, and the bottom surface 70d. 3B to 3D, as an example, the surface on the positive side in the X-axis direction is referred to as side surface 70e, and the surface on the negative side in the X-axis direction is referred to as side surface 70f. Note that in this embodiment, as an example, the main surface 70a and the back surface 70b have the same shape.

[0087] As shown in FIGS. 3A and 3C , the high-side source terminal 6H and the low-side source terminal 6L protrude from the top surface 70c of the source-side main body 7 in a direction perpendicular to the top surface 70c (the positive direction of the Y-axis). The high-side source terminal 6H includes a rod-shaped metal terminal 60H made of metal and a cover member 61H. The metal terminal 60H is fixed to the source-side main body 7 while protruding from the top surface 70c in a direction perpendicular to the top surface 70c (the positive direction of the Y-axis). For example, one end of the metal terminal 60H in the extension direction has a shape that allows it to be inserted into a female terminal of a meter (the high-side output terminal 210H of the meter 200, described below). The other end of the metal terminal 60H in the extension direction is fixed inside the source-side main body 7 and connected to the second wiring 13 by a crimp terminal, soldering, or the like.

[0088] The cover member 61H is formed of the same insulating material (e.g., resin) as the cover member 41H, for example, by known injection molding technology. As shown in FIG. 3C , the cover member 61H is formed in a cylindrical shape. The inner diameter of the cover member 61H is larger than the maximum outer diameter of the rod-shaped metal terminal 60H. The cover member 61H is disposed coaxially with and spaced apart from the metal terminal 60H. One end of the cover member 61H, i.e., the end on the Y-axis direction negative side, is inserted into the source-side main body 7 and supported by the source-side main body 7.

[0089] Here, it is preferable that the color of the surface of the cover member 61H is different from the color of the surfaces (principal surface 70a and back surface 70b) of the source-side main body portion 7. For example, the cover member 61H is colored red, and the principal surface 50a and back surface 50b of the source-side main body portion 7 are colored black (a color other than red).

[0090] Like the high-side source terminal 6H, the low-side source terminal 6L includes a rod-shaped metal terminal 60L made of metal and a cover member 61L. The metal terminal 60L is fixed to the source-side main body 7 in a state where it protrudes from the upper surface 70c in a direction perpendicular to the upper surface 70c (the positive direction of the Y-axis). For example, one axial end of the metal terminal 60L has a shape that allows it to be inserted into a female terminal of a measuring device (a low-side output terminal 210L of the measuring device 200, described below). The other axial end of the metal terminal 60L is fixed inside the source-side main body 7 and is connected to the fourth wiring 15 by a crimp terminal, soldering, or the like.

[0091] The cover member 61L is formed into a cylindrical shape from an insulating material (e.g., resin). For example, the cover member 61L and the source-side main body 7 are integrally molded by known injection molding technology. The inner diameter of the cover member 61L is larger than the maximum outer diameter of the rod-shaped metal terminal 60H. The cover member 61L is disposed coaxially with and spaced apart from the metal terminal 60L.

[0092] As with the high-side cover member 61H, the cover member 61L and the source-side main body portion 7 may be formed separately, and the end of the cover member 61L on the negative side of the Y axis direction may be inserted into the source-side main body portion 7 and fixed in place.

[0093] Furthermore, it is preferable that the color of the surface of the cover member 61L is the same as or similar to the color of the surface (principal surface 70a and back surface 70b) of the source-side main body portion 7. For example, the cover member 61L is colored black, and the principal surface 70a and back surface 70b of the source-side main body portion 7 are colored black.

[0094] As described above, the source-side body portion 7 has a second display portion 77 formed therein. Specifically, similar to the sense-side body portion 5, the source-side body portion 7 has an opening (through-hole) 71 formed therein, through which a portion of the high-side source terminal 6H can be seen. For example, as shown in FIGS. 3A and 3B , the opening 71 is formed in a region of the source-side body portion 7 that overlaps with one end of the inserted high-side source terminal 6H when viewed from a direction intersecting the direction in which the cover member 61H extends (e.g., the Z-axis direction). That is, the opening 71 and a portion 610 of the cover member 61H that can be seen through the opening 71 form the second display portion 77. Here, the opening 71 may be formed in at least one of the main surface 70a and the back surface 70b of the source-side body portion 7. In the present embodiment, as an example, the opening 71 is formed in both the main surface 70a and the back surface 70b.

[0095] 3A , a portion of the high-side source terminal 6H visible through the opening 71 may be formed to protrude outward from the opening 71. That is, a protrusion may be formed on the outer peripheral surface of the cover member 61H of the high-side source terminal 6H formed in a cylindrical shape, and the protrusion may protrude outward from the opening 71 of the source-side main body 7 when one end of the cover member 61H is inserted into the source-side main body 7.

[0096] Furthermore, information (mark) indicating that it is a source-side plug may be provided on at least one of the main surface 70a, the back surface 70b, and the bottom surface 70d of the source-side body portion 7. For example, as shown in FIGS. 3A and 3B , a mark 75 meaning "SOURCE" may be provided on the main surface 70a and the back surface 70b. Furthermore, for example, an "H" mark indicating a high-side terminal and an "L" mark indicating a low-side terminal may be provided on both sides of the mark 75 in the X-axis direction.

[0097] As shown in FIGS. 3A and 3D, it is preferable that the mark 53 is not provided on the source-side main body portion 7 (upper surface 70c).

[0098] Similar to the sense side body portion 5, the source side body portion 7 may have a shape that facilitates insertion and removal of the source side plug 3 into and from a measuring instrument. Specifically, the two side surfaces 70e, 70f of the source side body portion 7 are formed in arc shapes that are recessed in the directions facing each other.

[0099] 3A and 3B , when the source-side body portion 7 is viewed in a direction perpendicular to the main surface 70a (Z-axis direction), an imaginary line that passes through the center of the source-side body portion 7 and is parallel to the direction in which the high-side source terminal 6H extends (Y-axis direction) is defined as a second center line S2. In this case, when viewed in the direction perpendicular to the main surface 70a (Z-axis direction), a distance L3 from the second center line S2 to end portions 74a of the two side surfaces 70e, 70f of the source-side body portion 7 on the top surface 70c side is preferably longer than a distance L4 from the second center line S2 to end portions 74b of the two side surfaces 70e, 70f on the bottom surface 70d side. In other words, when the direction away from the second center line S2 along the X-axis direction is defined as the height direction of the side surfaces 70 e, 70 f, the curvatures of the two side surfaces 70 e, 70 f may be set so that the end portions 74 a, which are the vertices of the two side surfaces 70 e, 70 f on the top surface 70 c side, are higher than the end portions 74 b, which are the vertices of the two side surfaces 70 e, 70 f on the bottom surface 70 d side. Furthermore, similar to the sense-side body 5, a plurality of protrusions 80 may be formed on the two side surfaces 70 e, 70 f of the source-side body 7 at a distance from each other.

[0100] Fig. 4 is a diagram schematically illustrating the appearance of measuring instrument 200 according to an embodiment. Fig. 5 is a diagram schematically illustrating the appearance of measuring unit 300 according to an embodiment. Fig. 6 is a diagram for explaining a method for connecting test lead 1 shown in Fig. 1 to measuring instrument 200. Fig. 7 is a diagram schematically illustrating the flow of current when measuring the electrical characteristics of a DUT by a four-terminal measurement method using test lead 1 shown in Fig. 1.

[0101] For convenience of explanation, FIG. 7 representatively shows the sense-side plug 2 and source-side plug 3 of the test lead 1.

[0102] As described above, measuring instrument 200 shown in Fig. 4 is a device that measures electrical characteristics such as the impedance of a DUT, and is, for example, an LCR meter, an ohm meter, a battery tester, etc. Fig. 4 shows the external appearance of measuring instrument 200 as a battery tester as an example.

[0103] Measuring instrument 200 includes measuring instrument main body 201, high-side output terminal 210H, low-side output terminal 210L, high-side input terminal 211H, and low-side input terminal 211L. Measuring instrument main body 201 includes measuring unit 207, operation unit 204, display device 202, and housing 205. Measuring unit 207 is housed in housing 205. Measuring unit 207 is a functional unit for measuring physical quantities of a DUT. Measuring unit 207 generates measurement signals to be applied to the DUT and measures the electrical characteristics of the DUT based on detection signals obtained when the measurement signals are applied to the DUT. For example, measurement unit 207 includes a generation circuit (e.g., a voltage source and a current source) that generates a measurement signal (voltage or current) and supplies it to high-side output terminal 210H and low-side output terminal 210L, and various sensors (e.g., a voltage sensor and a current sensor) that detect the voltage or current input from high-side input terminal 211H and low-side input terminal 211L via the DUT. Measurement unit 207 also includes an A / D converter that converts the sensor detection signal into a digital signal, and a program processor (e.g., a microcomputer) that calculates physical quantities related to the DUT based on the digital signal and displays the measurement results on display device 202. The program processor controls the generation circuit, the sensor, the A / D converter, and display device 202 in response to, for example, an operation input to operation unit 204 or a command signal from an external device (e.g., a personal computer) connected to measuring instrument 200, thereby measuring the DUT and providing overall control of measuring instrument 200.

[0104] The housing 205 is formed, for example, in the shape of a rectangular parallelepiped. The housing 205 is made, for example, of a metal material. One surface of the housing 205 is provided with feet 206 for supporting the measuring device 200 on a flat surface such as a laboratory table. In the following description, the surface on which the feet 206 are located is referred to as the bottom surface of the housing 205 (the measuring device main body 201), and the surface opposite the bottom surface is referred to as the top surface of the housing 205 (the measuring device main body 201). Furthermore, the surface that intersects the top and bottom surfaces and on which the display screen of the display device 202 is located is referred to as the front surface of the housing 205 (the measuring device main body 201).

[0105] As shown in FIG. 4, on one face (front face) 201A of rectangular parallelepiped housing 205, for example, there are arranged high-side output terminal 210H, low-side output terminal 210L, high-side input terminal 211H, low-side input terminal 211L, display device 202 such as an LCD, power switch 203 for switching between starting and stopping measuring instrument 200, and operation unit 204 consisting of a group of switches for switching between various functions.

[0106] The high-side output terminal 210H and the low-side output terminal 210L are terminals that output a measurement signal to be applied to the DUT. Here, the measurement signal is a DC or AC signal (voltage or current). The high-side input terminal 211H and the low-side input terminal 211L are terminals that input a detection signal when the measurement signal is applied to the DUT. The detection signal is a signal that corresponds to the voltage generated in the DUT or the current that flows through the DUT when the measurement signal is applied to the DUT.

[0107] The high-side output terminal 210H, the low-side output terminal 210L, the high-side input terminal 211H, and the low-side input terminal 211L are each formed, for example, as a female connector. The high-side output terminal 210H, the low-side output terminal 210L, the high-side input terminal 211H, and the low-side input terminal 211L are arranged on one surface of the housing 205. For example, the high-side output terminal 210H and the low-side output terminal 210L are arranged side by side in a direction from the top surface to the bottom surface of the housing 205 (Y-axis direction), and the high-side input terminal 211H and the low-side input terminal 211L are arranged side by side in a direction from the top surface to the bottom surface of the housing 205 (Y-axis direction).

[0108] 4 shows a case where the high-side output terminal 210H and the low-side output terminal 210L are arranged on the negative side of the X axis direction, and the high-side input terminal 211H and the low-side input terminal 211L are arranged on the positive side of the X axis direction, but this is not limiting. For example, the high-side output terminal 210H and the low-side output terminal 210L may be arranged on the positive side of the X axis direction, and the high-side input terminal 211H and the low-side input terminal 211L may be arranged on the negative side of the X axis direction.

[0109] One surface (front) of the housing 205 is formed with a first guide frame 221 for visually guiding the connection destination of the source side plug 3 of the test lead 1 in the measuring instrument 200, and a second guide frame 222 for visually guiding the connection destination of the sense side plug 2 of the test lead 1 in the measuring instrument 200.

[0110] 4 , the first guide frame 221 is formed to surround the high-side output terminal 210H and the low-side output terminal 210L, and the second guide frame 222 is formed to surround the high-side input terminal 211H and the low-side input terminal 211L. For example, the first guide frame 221 and the second guide frame 222 may be a continuous or discontinuous rectangular or elliptical line drawing (print) drawn on one surface 201A of the housing 205, or may be a continuous or discontinuous rectangular groove, protrusion, or the like formed on one surface of the housing 205.

[0111] 4, the word "SOURCE" may be written on surface 201A of housing 205 adjacent to first guide frame 221 or overlapping with a portion of first guide frame 221. Similarly, the word "SENSE" may be written on surface 201A of housing 205 adjacent to second guide frame 222 or overlapping with a portion of the second guide frame.

[0112] Furthermore, a mark 240 having a shape corresponding to the mark 53 formed on the test lead 1 may be formed adjacent to the second guide frame 222 or overlapping with part of the second guide frame 222. For example, Fig. 4 shows a case in which a triangular mark 240 is formed in an area on the high-side input terminal 211H side that overlaps with part of the second guide frame 222.

[0113] As shown in FIG. 5 , the test lead 1 and the measuring instrument 200 constitute a single measurement unit 300. When measuring the electrical characteristics of a DUT using the four-terminal measurement method in the measurement unit 300, the high-side source terminal 6H and the low-side source terminal 6L of the source-side plug 3 are connected to the high-side output terminal 210H and the low-side output terminal 210L, respectively, within the first guide frame 221 of the measuring instrument 200, as shown in FIG. 6 . Also, the high-side sense terminal 4H and the low-side sense terminal 4L of the sense-side plug 2 of the test lead 1 are connected to the high-side input terminal 211H and the low-side input terminal 211L, respectively, within the second guide frame 222 of the measuring instrument 200. At this time, the user simply connects the sense-side plug 2 to the measuring instrument 200 so that the mark 53 formed on the sense-side plug 2 corresponds to the triangular mark 240 formed on the surface 201A of the measuring instrument 200.

[0114] Consider the case shown in FIG. 6 where the test lead 1 is connected to the measuring instrument 200 and the electrical characteristics of the DUT are measured using an AC measurement signal by a four-terminal measurement method. In this case, the measurement signal output from the measuring instrument 200 is input to the high-side source terminal 6H and the low-side source terminal 6L of the source-side plug 3. At this time, as shown in FIG. 7 , the current of the AC measurement signal flows through the second wiring 13 and the fourth wiring 15, and the current of the detection signal flows through the first wiring 12 and the third wiring 14. Therefore, unlike the test lead 90 of the previously studied example, a loop is not formed between the first wiring 12 and the third wiring 14 and the second wiring 13 and the fourth wiring 15. This prevents large eddy currents from being generated in the metal, as was the case with the test lead 90 of the previously studied example, even when metal is disposed around the sense-side plug 2 and the source-side plug 3. Although loops are formed between the first wiring 12 and the third wiring 14 and between the second wiring 13 and the fourth wiring 15, these loops are small, so even if eddy currents are generated, it is considered that their effect on the measurement can be ignored.

[0115] That is, the test lead 1 according to the embodiment includes the sense plug 2, which pairs the high-side sense terminal 4H and the low-side sense terminal 4L, and the source plug 3, which pairs the high-side source terminal 6H and the low-side source terminal 6L, and therefore can suppress the generation of eddy currents when measuring the electrical characteristics of a DUT using the four-terminal measurement method, thereby enabling more accurate measurements.

[0116] Furthermore, in test lead 1, the high-side sense terminal 4H and the low-side sense terminal 4L have different appearances (colors), and the high-side source terminal 6H and the low-side source terminal 6L have different appearances (colors). This allows the user, when connecting test lead 1 to meter 200, to easily recognize which of the two terminals of sense plug 2 is the high-side sense terminal 4H, and which of the two terminals of source plug 3 is the high-side source terminal 6H. This reduces the occurrence of incorrect connection of test lead 1 to meter 200 by the user.

[0117] 6 , after test lead 1 is connected to meter 200, high-side sense terminal 4H, low-side sense terminal 4L, high-side source terminal 6H, and low-side source terminal 6L are inserted into meter 200, making it difficult for a user to see these terminals from the outside. However, as described above, test lead 1 has a first indicator 57 of the same color as the surface of high-side sense terminal 4H formed in the area on the surface of sense side main body 5 facing high-side sense terminal 4H, and a second indicator 77 of the same color as the surface of high-side source terminal 6H formed in the area on the surface of source side main body 7 facing high-side source terminal 6H. This allows a user to easily distinguish between the high-side terminals and the low-side terminals of sense side plug 2 and source side plug 3, even after test lead 1 is connected to meter 200.

[0118] As described above, the first display unit 57 is made up of the opening 51 formed in the sense side body unit 5 and a part of the high side sense terminal 4H visible through the opening 51, and the second display unit 77 is made up of the opening 71 formed in the source side body unit 7 and a part of the high side source terminal 6H visible through the opening 71. This makes it possible to easily realize the first display unit 57 and the second display unit 77, for example, by simply forming the openings 51, 71 when forming the sense side body unit 5 and the source side body unit 7 by injection molding.

[0119] Furthermore, a mark 53 is provided on the bottom surface 50d of the sense side plug 2. This allows the user to easily identify which plug is the sense side plug 2 when connecting the test lead 1 to the measuring instrument 200, thereby further reducing the occurrence of incorrect connection of the test lead 1 to the measuring instrument 200 by the user.

[0120] 4 and 6 , a first guide frame 221 that surrounds the high-side input terminal 211H and the low-side input terminal 211L, and a second guide frame 222 that surrounds the high-side output terminal 210H and the low-side output terminal 210L are formed on one surface 201A of meter 200. This allows the user to connect the sense-side plug 2 and the source-side plug 3 of test lead 1 to meter 200 by following the first guide frame 221 and the second guide frame 222, thereby reducing the occurrence of incorrect connection of test lead 1 to meter 200.

[0121] Furthermore, as shown in FIG. 6 , by forming mark 53 on the side of high-side sense terminal 4H on bottom surface 50d of test lead 1, the user can simply connect sense-side plug 2 to meter 200 so that mark 53 on sense-side plug 2 corresponds to displayed mark 240 formed on surface 201A of meter 200, thereby making it possible to more reliably prevent incorrect connection.

[0122] Furthermore, the two side surfaces 50 e, 50 f of the sense side body 5 are formed in arc shapes recessed in the direction facing each other, and the two side surfaces 70 e, 70 f of the source side body 7 are formed in arc shapes recessed in the direction facing each other. This makes it easier for the user to grip the sense side plug 2 and the source side plug 3, and makes it easier for the user to apply force to the sense side plug 2 and the source side plug 3 when inserting or removing the sense side plug 2 and the source side plug 3 into or from the measuring instrument.

[0123] In addition, in the sense-side body 5, when viewed from a direction perpendicular to the main surface 50a, a distance L1 from the first center line S1 to the ends 54a of the two side surfaces 50e, 50f of the sense-side body 5 on the top surface 50c side is longer than a distance L2 from the first center line S1 to the ends 54b of the two side surfaces 50e, 50f on the bottom surface 50d side. Similarly, in the source-side body 7, when viewed from a direction perpendicular to the main surface 70a, a distance L3 from the second center line S2 to the ends 74a of the two side surfaces 70e, 70f of the source-side body 7 on the top surface 70c side is longer than a distance L4 from the second center line S2 to the ends 74b of the two side surfaces 70e, 70f on the bottom surface 70d side. This makes it easier for the user to hook their fingers onto the sense side main body portion 5 and the source side main body portion 7 when removing the test lead 1 from the measuring instrument 200, making it even easier for the user to remove the sense side plug 2 and the source side plug 3 from the measuring instrument 200.

[0124] <<Extending the Embodiments>> The invention made by the inventor of the present application has been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited thereto and can be modified in various ways without departing from the spirit of the invention.

[0125] For example, in the above embodiment, the high-side contact portion 8H and the low-side contact portion 8L of the test lead 1 are shaped like probes, but various shapes can be adopted for the high-side contact portion 8H and the low-side contact portion 8L. For example, as shown in FIG. 8, the high-side contact portion 8Ha and the low-side contact portion 8La may be shaped like a clip (pinch).

[0126] FIG. 8 is a diagram schematically illustrating the configuration of a test lead 1A according to another embodiment of the present invention.

[0127] Specifically, in the test lead 1A, the high-side contact portion 8Ha has a high-side contactor 31H consisting of two probes and a pair of gripping portions 32H that control the opening and closing of the two probes that make up the high-side contactor 31H. Similarly, the low-side contact portion 8La has a low-side contactor 31L consisting of two probes and a pair of gripping portions 32L that control the opening and closing of the two probes that make up the low-side contactor 31L. The gripping portions 32H, 32L have biasing means such as springs.

[0128] For example, in the high-side contact portion 8Ha, when no external force is applied to the gripping portion 32H, a force from the biasing means of the gripping portion 32H is applied in a direction that moves the pair of probes constituting the high-side contactor 31H closer to each other, thereby closing the high-side contactor 31H. On the other hand, when a user operates the high-side contact portion 8Ha and applies a force to the gripping portion 32H in a direction that moves the pair of gripping portions 32H closer to each other, a force is applied in the opposite direction to the force from the biasing means of the gripping portion 32H, causing the pair of probes constituting the high-side contactor 31H to move away from each other, thereby opening the high-side contactor 31H. The low-side contact portion 8La is operated in a similar manner. The test lead 1A shown in FIG. 8 , like the test lead 1 described above, can suppress the generation of eddy currents while reducing the occurrence of incorrect connection to a measuring instrument by the user.

[0129] Furthermore, in the above embodiment, the first indicator 57 is configured by the opening 51 formed in the sense-side main body 5 and a part of the high-side sense terminal 4H visible through the opening 51, and the second indicator 77 is configured by the opening 71 formed in the source-side main body 7 and a part of the high-side source terminal 6H visible through the opening 71, but this is not limiting. For example, without forming the opening 51, the first indicator 57 may be formed by forming a protrusion or a geometric pattern in the same color as the high-side sense terminal 4H (cover member 41H) on the surface of the sense-side main body 5 on the side of the high-side sense terminal 4H. The same applies to the second indicator 77.

[0130] In the above embodiment, the appearances of the high-side sense terminal 4H and the low-side sense terminal 4L are made different from each other by making the surface colors of the high-side sense terminal 4H and the low-side sense terminal 4L different from each other, but this is not limited to this. Specifically, the appearances of the high-side sense terminal 4H and the low-side sense terminal 4L may be made different from each other by making the shapes of the high-side sense terminal 4H and the low-side sense terminal 4L different from each other. For example, the cover member 61H for the high-side sense terminal 4H may be polygonal tubular, and the cover member 61L for the low-side sense terminal 4L may be cylindrical.

[0131] Furthermore, the dimensions of the high-side sense terminal 4H and the low-side sense terminal 4L may be different from each other, thereby making the appearances of the high-side sense terminal 4H and the low-side sense terminal 4L different from each other. For example, in the sense-side plug 2, the length of the portion of the high-side sense terminal 4H protruding from the sense-side main body 5 (the length of the high-side sense terminal 4H in the Y-axis direction) may be different from the length of the portion of the low-side sense terminal 4L protruding from the sense-side main body 5 (the length of the low-side sense terminal 4L in the Y-axis direction). For example, the length of the high-side sense terminal 4H in the Y-axis direction may be shorter (or longer) than the length of the low-side sense terminal 4L in the Y-axis direction. Similarly, in the source-side plug 3, the length of the high-side source terminal 6H in the Y-axis direction may be shorter (or longer) than the length of the low-side source terminal 6L.

[0132] When the high-side sense terminal 4H and the low-side sense terminal 4L have different shapes or dimensions as described above, the color of the cover member 61H of the high-side sense terminal 4H may be different from the color of the cover member 61L of the low-side sense terminal 4L, as in the above embodiment. The same applies to the high-side source terminal 6H and the low-side source terminal 6L.

[0133] Furthermore, in the above embodiment, a predetermined mark 53 is formed on the surface of the sense side body portion 5, but it may be formed on either the sense side body portion 5 or the source side body portion 7. For example, the mark 53 indicating the source side may be formed on the surface of the source side body portion 7. For example, the mark 53 may be formed on at least one of the main surface 70a, the back surface 70b, the top surface 70c, the bottom surface 70d, and the two side surfaces 70e and 70f, but it is preferable that the mark 53 be formed on the bottom surface 70d on the side of the high-side source terminal 6H. In this case, for example, it is preferable that a mark 240 having a shape corresponding to the mark 53 formed on the test lead 1 is formed adjacent to or overlapping a part of the first guide frame 221.

[0134] Furthermore, in the above embodiment, the case where the openings (through holes) 51, 71 are formed in the sense side body portion 5 and the source side body portion 7, respectively, has been exemplified, but instead of (or in addition to) the openings (through holes) 51, 71, the surfaces of the sense side body portion 5 and the source side body portion 7 may be color-coded. This will be explained below with reference to the drawings.

[0135] Fig. 9 is a diagram schematically showing the configuration of a test lead 1B according to another embodiment of the present invention. Fig. 10A is a diagram schematically showing the configuration of a sense-side plug 2B of the test lead 1B shown in Fig. 9. Fig. 10B is a diagram schematically showing the configuration of a source-side plug 3B of the test lead 1B shown in Fig. 9.

[0136] The test lead 1B shown in FIG. 9 differs from the test leads 1 and 1A in that the area on the high-side sense terminal 4H side and the area on the low-side sense terminal 4L side of the sense-side main body 5 are colored different colors, and the area on the high-side source terminal 6H side and the area on the low-side source terminal 6L side of the source-side main body 7 are colored different colors.

[0137] For example, if the first center line S1 of the sense side main body portion 5 is used as a reference to define the region 5BA_1 on the high side sense terminal 4H side, and the first center line S1 of the sense side main body portion 5 is used as a reference to define the region 5BA_2 on the low side sense terminal 4L side, the region 5BA_1 on the high side sense terminal 4H side is colored red, and the region 5BA_2 on the low side sense terminal 4L side is colored black.

[0138] For example, if the region 7BA_1 on the high-side source terminal 6H side is defined based on the second center line S2 of the source-side main body portion 7, and the region 7BA_2 on the low-side source terminal 6L side is defined based on the second center line S2 of the source-side main body portion 7, the region 7BA_1 on the high-side source terminal 6H side is colored red, and the region 7BA_2 on the low-side source terminal 6L side is colored black.

[0139] At least one of the main surface 50a, the back surface 50b, and the bottom surface 50d of the sense-side body portion 5 may be marked with information (marks) indicating that it is a sense-side plug. For example, as shown in FIG. 10A , a mark 58 indicating "SENSE" may be marked on the bottom surface 50d. As shown in FIG. 9 , the main surface 50a and the back surface 50b may be marked with an "H" mark indicating a high-side terminal and an "L" mark indicating a low-side terminal. Similarly, at least one of the main surface 70a, the back surface 70b, and the bottom surface 70d of the source-side body portion 7 may be marked with information (marks) indicating that it is a source-side plug. For example, as shown in FIG. 10B , a mark 59 indicating "SOURCE" may be marked on the bottom surface 70d. As shown in FIG. 9 , the main surface 70a and the back surface 70b may be marked with an "H" mark indicating a high-side terminal and an "L" mark indicating a low-side terminal.

[0140] As described above, according to the test lead 1B of the embodiment, the region 5BA_1 on the high-side sense terminal 4H side and the region 5BA_2 on the low-side sense terminal 4L side in the sense-side main body 5 are colored in different colors, and the region 7BA_1 on the high-side source terminal 6H side and the region 7BA_2 on the low-side source terminal 6L side in the source-side main body 7 are colored in different colors. As a result, even when the test lead 1B is connected to the measuring instrument 200, it is possible to easily identify which of the plugs of the test lead 1B is the high-side terminal.

[0141] In the above embodiment, the two side surfaces 50e, 50f of the sense side body 5 are formed so that the distance L1 from the first center line S1 to the end portions 54a of the two side surfaces 50e, 50f on the top surface 50c side is longer than the distance L2 from the first center line S1 to the end portions 54b of the two side surfaces 50e, 50f on the bottom surface 50d side (L2<L1). However, this is not limited to this. For example, the two side surfaces 50e, 50f of the sense side body 5 may be formed so that L1=L2 or L1<L2. The same applies to the two side surfaces 70e, 70f of the source side body 7 (L3=L4 or L4<L3).

[0142] REFERENCE SIGNS LIST 1, 1A, 1B... test lead, 2... sense side plug, 3... source side plug, 4H... high side sense terminal, 4L... low side sense terminal, 5... sense side main body portion, 6H... high side source terminal, 6L... low side source terminal, 7... source side main body portion, 8H, 8Ha... high side contact portion, 8L, 8La... low side contact portion, 9H, 31H... high side contactor, 9L, 31L... low side contactor, 10H, 10L, 32H, 32L... grip portion, 11... wiring portion, 12... first wiring, 13... second wiring, 14... third wiring, 15... fourth wiring, 16... routing portion, 40H, 40L, 60H, 60L... metal terminal, 41H, 41L, 61H, 61L... cover member, 50a, 70a... main surface, 50 b, 70b...back surface, 50c, 70c...top surface, 50d, 70d...bottom surface, 50e, 50f, 70e, 70f...side surface, 51, 71...opening, 53, 55...mark, 57...first display unit, 77...second display unit, 54a, 54b, 74a, 74b...end portion, 200...measuring instrument, 201...measuring instrument main body, 205...housing, 207...measuring unit, 210H...high side output terminal, 210L...low side output terminal, 211H...high side input terminal, 211L...low side input terminal, 221...first guide frame, 222...second guide frame, 300...measuring unit, 410...part of cover member, 610...part of cover member, L1, L2, L3, L4...distance, S1...first center line, S2...second center line.

Claims

1. A test lead comprising: a sense-side plug having a high-side sense terminal and a low-side sense terminal; a source-side plug having a high-side source terminal and a low-side source terminal; a high-side contact portion including a high-side contactor for contacting an object to be measured; a low-side contact portion including a low-side contactor for contacting the object to be measured; and a wiring portion including a first wiring connecting the high-side sense terminal and the high-side contactor, a second wiring connecting the high-side source terminal and the high-side contactor, a third wiring connecting the low-side sense terminal and the low-side contactor, and a fourth wiring connecting the low-side source terminal and the low-side contactor, wherein the high-side sense terminal and the low-side sense terminal have mutually different appearances, and the high-side source terminal and the low-side source terminal have mutually different appearances.

2. A test lead as claimed in claim 1, wherein the high-side sense terminal and the low-side sense terminal have a surface colour that is different from each other, and the high-side source terminal and the low-side source terminal have a surface colour that is different from each other.

3. A test lead as claimed in claim 1, wherein the high-side sense terminal and the low-side sense terminal have different shapes or dimensions, and the high-side source terminal and the low-side source terminal have different shapes or dimensions.

4. A test lead as defined in claim 2, wherein the high-side sense terminal, the low-side sense terminal, the high-side source terminal, and the low-side source terminal are each formed in a male shape, the sense-side plug supports one end of the high-side sense terminal and further has a sense-side main body that supports one end of the low-side sense terminal, the source-side plug supports one end of the high-side source terminal and further has a source-side main body that supports one end of the low-side source terminal, a first display section of the same color as the surface of the high-side sense terminal is formed in an area on the surface of the sense-side main body facing the high-side sense terminal, and a second display section of the same color as the surface of the high-side source terminal is formed in an area on the surface of the source-side main body facing the high-side source terminal.

5. A test lead according to claim 4, wherein the high-side sense terminal, the low-side sense terminal, the high-side source terminal, and the low-side source terminal each have a rod-shaped metal terminal and a tubular cover member coaxial with the metal terminal and covering the periphery of the metal terminal; the surface color of the cover member of the high-side sense terminal is different from the surface color of the sense-side main body; the surface color of the cover member of the high-side source terminal is different from the surface color of the source-side main body; the sense-side main body holds the cover member of the high-side sense terminal with one end of the cover member of the high-side sense terminal inserted into the sense-side main body; the source-side main body holds the cover member of the high-side source terminal with one end of the cover member of the high-side source terminal inserted into the source-side main body; a first opening is formed in a region of the sense-side main body that overlaps with the one end of the cover member of the inserted high-side sense terminal when viewed from a direction intersecting the direction in which the cover member of the high-side sense terminal extends; A test lead in which a second opening is formed in a region of the source side main body that overlaps with one end side of the cover member of the inserted high side source terminal when viewed from a direction intersecting the direction in which the cover member of the high side source terminal extends, the first display unit is composed of the first opening and a part of the cover member of the high side sense terminal that is visible from the first opening, and the second display unit is composed of the second opening and a part of the cover member of the high side source terminal that is visible from the second opening.

6. A test lead according to claim 5, wherein the sense side body portion and the source side body portion are each formed in a rectangular parallelepiped shape, and the sense side body portion has a first main surface, a first back surface opposite to the first main surface, a first top surface that intersects with the first main surface and the first back surface and from which the high side sense terminal and the low side sense terminal are disposed so as to protrude, a first bottom surface opposite to the first top surface and through which the first wiring and the second wiring are inserted, and two first side surfaces that intersect with the first main surface, the first back surface, the first top surface, and the first bottom surface; the source side body portion has a second main surface, a second back surface opposite to the second main surface, a second top surface that intersects with the second main surface and the second back surface and from which the high-side source terminal and the low-side source terminal are protruding, a second bottom surface opposite to the second top surface and through which the third wiring and the fourth wiring are inserted, and two second side surfaces that intersect with the second main surface, the second back surface, the second top surface, and the second bottom surface; in the sense side body portion, the first opening is formed in at least one of the first main surface and the first back surface; and in the source side body portion, the second opening is formed in at least one of the second main surface and the second back surface.

7. A test lead according to claim 6, wherein the two first side surfaces are formed in arc shapes recessed in the direction facing each other, and the two second side surfaces are formed in arc shapes recessed in the direction facing each other.

8. A test lead as defined in claim 7, wherein, when viewed in a direction perpendicular to the first main surface, an imaginary line passing through the center of the sense side body and parallel to the direction in which the high-side sense terminal extends is defined as a first center line, and when viewed in a direction perpendicular to the second main surface, an imaginary line passing through the center of the source side body and parallel to the direction in which the high-side source terminal extends is defined as a second center line, when viewed in a direction perpendicular to the first main surface, the distance from the first center line to the ends of the two first side surfaces of the sense side body on the first top surface side is longer than the distance from the first center line to the ends of the two first side surfaces on the first bottom surface side, and when viewed in a direction perpendicular to the second main surface, the distance from the second center line to the ends of the two second side surfaces of the source side body on the second top surface side is longer than the distance from the second center line to the ends of the two second side surfaces on the second bottom surface side.

9. The test lead according to claim 6, wherein a predetermined mark is formed on the surface of the sense side body portion or the surface of the source side body portion.

10. A test lead according to claim 9, wherein the predetermined mark is formed on the first upper surface of the sense side body portion or the second upper surface of the source side body portion.

11. A measuring instrument for measuring the electrical characteristics of an object to be measured, comprising: a measuring unit that generates a measurement signal to be applied to the object to be measured and measures the electrical characteristics of the object to be measured based on a detection signal when the measurement signal is applied to the object to be measured; a measuring unit main body including a housing that houses the measurement unit; high-side output terminals and low-side output terminals that are arranged on one surface of the housing and output the measurement signal; and high-side input terminals and low-side input terminals that are arranged on the one surface of the housing and input the detection signal; and a first guide frame is formed on the one surface in a manner that surrounds the high-side output terminal and the low-side output terminal, and a second guide frame is formed in a manner that surrounds the high-side input terminal and the low-side input terminal.

12. A measurement unit comprising the test lead of any one of claims 1 to 10 and the measuring instrument of claim 11, wherein the high-side sense terminal is configured to be connectable to the high-side input terminal, the low-side sense terminal is configured to be connectable to the low-side input terminal, the high-side source terminal is configured to be connectable to the high-side output terminal, and the low-side source terminal is configured to be connectable to the low-side output terminal.

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