JP6390184B2 - Electrode member, composite electrode, and electrode member manufacturing method - Google Patents

Description

  The present invention relates to an electrode member used in electrochemical measurement using a comparative electrode such as pH measurement, ion concentration measurement, and oxidation-reduction potential (ORP) measurement, a composite electrode provided with the electrode member, and a method for producing the electrode member. Is.

  Conventionally, a pH glass electrode provided with a glass sensitive film sensitive to hydrogen ions is widely used as a measurement electrode (working electrode) for pH measurement. In the pH measurement, the measurement electrode and the reference electrode (reference electrode) are immersed in the test solution, and the pH value of the test solution is obtained from the potential difference between the two electrodes. A composite electrode for pH measurement in which a measurement electrode and a comparative electrode are integrally formed is also widely used.

  Further, as a configuration that enables measurement with higher accuracy, a differential measurement type pH composite electrode that employs a pH glass electrode as an internal electrode of a comparison electrode is known. This pH composite electrode has two pH glass electrodes, one pH glass electrode is used as a measurement electrode, and the other pH glass electrode is provided as a comparison electrode. The pH glass electrode provided in the comparison electrode is immersed in a pH buffer solution accommodated in the “electrode chamber” and passes through the “salt bridge chamber” having a liquid junction provided adjacent to the electrode chamber. Electrical continuity with the test solution is obtained. The salt bridge chamber (and its internal liquid), the electrode chamber (and its internal liquid), and the pH glass electrode in the electrode chamber constitute a comparative electrode. Then, with the liquid earth electrode in common, the potential difference between the measurement electrode and the liquid earth electrode, the potential difference between the comparison electrode and the liquid earth electrode are measured, and the potential of the liquid earth electrode is canceled and compared with the measurement electrode. A potential difference with the electrode is obtained, and a pH value is obtained from this potential difference. This pH composite electrode uses a pH glass electrode as the internal electrode of the reference electrode, so that the potential of the reference electrode is stable, and the effect of electrical noise can be reduced by measuring the potential difference with respect to the common liquid earth electrode. Therefore, more accurate measurement is possible.

  Although such a pH composite electrode enables more accurate measurement, since two pH glass electrodes are required for the measurement electrode and the comparison electrode, the configuration is easily complicated and enlarged. It has not been widely used. On the other hand, Patent Documents 1 and 2 disclose a differential measurement type pH composite electrode having a relatively simple configuration and employing a pH glass electrode as an internal electrode of a comparative electrode. The pH composite electrode described in Patent Documents 1 and 2 is provided with a pH glass sensitive film for measurement at the tip of one tubular member, and a pH glass sensitive film for comparison at the side, and the inside of this tubular member. A chamber communicating with each of the pH glass sensitive membranes, and a space between the tubular member and the outer cylinder covered on the outer side using a plurality of packings and liquid junctions to partition the electrode chamber, It forms a salt bridge room.

Japanese Patent No. 4996260 Special table 2011-501193 gazette

  However, the differential measurement type pH composite electrode employing a glass electrode as the internal electrode of the comparative electrode described in Patent Documents 1 and 2 still has a complicated structure for forming the electrode chamber and the salt bridge chamber of the comparative electrode. It is easy to enlarge. Further, since many packings and liquid junctions are used, there is a concern about the occurrence of liquid leakage.

  Further, regarding the pH glass sensitive film for comparison, Patent Document 1 describes a columnar shape and Patent Document 2 describes a patch, but a specific manufacturing method thereof is not disclosed.

  In the above, the conventional problem has been described by taking the case where the measurement target is pH as an example. However, the measurement target is an ion concentration or ORP other than hydrogen ions, and the measurement electrode is a corresponding measurement electrode (ion concentration measurement electrode, The same problem may occur when the ORP measurement electrode is used.

  Accordingly, an object of the present invention is to provide a composite electrode adopting a glass electrode as an internal electrode of a comparative electrode, and an electrode member used therefor, having a simpler configuration.

  Another object of the present invention is to provide an electrode member manufacturing method that can more easily manufacture an electrode member used for a composite electrode that employs a glass electrode as an internal electrode of a comparative electrode with a simpler configuration. Is to provide.

The above object is achieved by the electrode member, the composite electrode, and the method for manufacturing the electrode member according to the present invention. In summary, the present invention is an electrode member used for a composite electrode having a measurement electrode and a comparison electrode, and the internal electrode of the comparison electrode is a glass electrode, and is formed to be long in the axial direction and on the tip side. a first tube made of glass whose ends sealed, enclosing the at least part of the opposite side of the base end side to the tip side of the first tube in the axial direction of the front end portion A glass-made second tube whose end is welded and sealed to the first tube, and at least a part of the proximal end side of the second tube in the axial direction, and the tip portion A glass-made third tube whose end on the side is welded and sealed to the second tube, and the first tube, the second tube, and the third tube are constitute a substantially triple pipe structure disposed coaxially, not surrounded by the second tube prior Symbol first tube Measuring titration, glass-sensitive film is provided on the band, a first storage portion for storing the first measuring electrode in electrode is immersed in the measuring electrode internal solution and the measuring electrode inner liquid by the tube is formed, before Symbol A cylindrical glass-sensitive film for comparison is welded and integrated into a part of the axial direction of the region surrounded by the third tube in the second tube, and the first tube and the first tube the second housing part is formed for accommodating the second ratio Ri by the the tube compare electrode inside internal solution, the second tube and the third tube and the O Ri ratio較用glass electrode internal solution and the comparative third housing part is formed for accommodating the comparative glass electrode in electrode is immersed in use glass electrode internal liquid, the second is not surrounded by said third tube in the tube region, the second liquid junction that allows electrical connection between inside and outside of the liquid containing portion is sealed, the measuring electrode, before The glass sensitive film for measurement, the first accommodating portion, the internal solution of the measurement electrode, and the inner electrode of the measurement electrode are configured, and the comparative electrode includes the glass sensitive film for comparison, the first electrode 2 containing part, the said comparison electrode inner internal liquid, the said 3rd accommodating part, the said glass electrode internal liquid for a comparison, the said glass electrode internal electrode for a comparison, and the said liquid junction part are comprised. It is an electrode member characterized by being made .

According to another aspect of the present invention , the composite electrode includes a measurement electrode and a comparison electrode, and the internal electrode of the comparison electrode is a glass electrode, and is formed to be long in the axial direction and has an end on the tip side. A first tube made of glass that forms a first housing portion that is sealed to store the measurement electrode internal liquid, and a proximal end opposite to the distal end side of the first tube in the axial direction A second electrode that surrounds at least a part of the portion side and is sealed by sealing the end portion of the tip end portion side of the first tube to the first tube. A second tube made of glass that forms a housing portion of the second tube, and at least a part of the proximal end portion side of the second tube in the axial direction, and an end portion on the distal end side of the second tube is the second tube A third housing portion is formed which is sealed by being welded and accommodates the liquid inside the glass electrode for comparison between the second tube. A third tube made of glass, wherein the first tube, the second tube, and the third tube constitute a triple-tube structure arranged substantially coaxially, A glass-sensitive film for measurement is provided in a region of the first tube that is not surrounded by the second tube, and a portion of the region of the second tube that is surrounded by the third tube in the axial direction. A cylindrical glass-sensitive film for comparison is welded and integrated, and electricity between liquids inside and outside the second housing portion is formed in a region of the second tube that is not surrounded by the third tube. And an electrode member in which a liquid junction part enabling a general connection is sealed, and a measurement arranged in the first housing part so as to be immersed in the liquid inside the measurement electrode housed in the first housing part So as to be immersed in the electrode inner electrode and the liquid in the glass electrode for comparison housed in the third housing portion A comparative glass electrode inner pole disposed in the third housing portion, and the electrode member is disposed so as to surround the electrode member along the axial direction. A sealing part that seals the opening of the end part of the outer cylinder on the tip end side in the axial direction and exposes the glass-sensitive film for measurement to the outside. An outer liquid junction that is provided in the sealing portion and enables electrical connection between the inner and outer liquids of the fourth housing portion, and the measurement electrode includes the measurement glass-sensitive film, The first containing part, the measurement electrode internal liquid, and the measurement electrode inner electrode are configured to include the comparison electrode, the comparative glass sensitive film, the second containing part, and the comparison. The electrode inner liquid, the third container, the comparative glass electrode inner liquid, and the ratio. A composite electrode comprising a comparative glass electrode inner pole, the liquid junction, the fourth housing portion, the comparison electrode outer internal liquid, and the outer liquid junction. Is provided.

According to still another aspect of the present invention, there is provided a method for producing an electrode member comprising a measurement electrode and a comparison electrode, wherein the internal electrode of the comparison electrode is a glass electrode . A step of adhering a glass film type of the glass sensitive film so as to seal the end, and the glass film adhering to the end of the stem tube by blowing air into the stem tube having the glass film type adhering to the end A step of blowing the seed, and joining the blown glass film types of the two stem tubes with the blown glass film species attached to the end portions, and a part of the axial direction And forming a glass tubular member in which a cylindrical glass-sensitive film constituting the comparative electrode is welded and integrated, and a glass stem tube having a diameter larger than that of the tubular member. The tubular member is arranged inside the large-diameter tubular member. And by welding one end of the tubular member and one end of the large-diameter tubular member, the one end of the tubular member is opened and the one end of the large-diameter tubular member is sealed A step of producing a first part of the tube structure, and the opened one end portion of the tubular member in the first part is an end tubular member formed of a glass stem tube, and the one end portion is Opened and sealed at the other end, the one end of the end tubular member provided with the glass-sensitive film for measurement constituting the measurement electrode is connected to the inside of the tubular member and the end tubular member. The step of producing a second part by welding so as to communicate with the inside, and the small-diameter tubular member formed of a glass stem tube having a smaller diameter than the tubular member, the tubular member in the second part And the inside of the end tubular member, the small diameter tubular One end of the material is connected to the end tubular member in the second part, the inside of the small diameter tubular member and a part of the sealed end of the end tubular member in the second part Before the step of producing the second part, after the step of producing the second part, and after the step of producing the third part. Before the step of producing the third part or after the step of producing the third part, the welded portion of the first part and the end tubular member in the axial direction of the end tubular member; A liquid junction that enables electrical connection between the inner and outer liquids of the end tubular member to the end tubular member at a position between the small diameter tubular member and the welded portion of the end tubular member. A method for producing an electrode member , comprising: enclosing a portion .

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the composite electrode which employ | adopted the glass electrode as the internal electrode of a comparison electrode of a simple structure, and the electrode member used for this. Moreover, according to the manufacturing method of the electrode member of this invention, it becomes possible to manufacture more easily the electrode member used for the composite electrode which employ | adopted the glass electrode as the internal electrode of a comparison electrode.

It is sectional drawing of the composite electrode which concerns on one Example of this invention. It is sectional drawing of the electrode member which concerns on one Example of this invention. It is sectional drawing which shows the other example of a liquid junction part. It is a schematic diagram which shows the manufacturing method of the electrode member which concerns on one Example of this invention. It is a schematic diagram which shows the manufacturing method of the electrode member which concerns on one Example of this invention. It is a schematic diagram which shows the manufacturing method of the electrode member which concerns on one Example of this invention. It is a schematic diagram which shows the other example of the manufacturing method of the electrode member which concerns on one Example of this invention. It is sectional drawing of the electrode member which concerns on the other Example of this invention. It is sectional drawing of the electrode member which concerns on the other Example of this invention.

  Hereinafter, the electrode member, the composite electrode, and the electrode member manufacturing method according to the present invention will be described in more detail with reference to the drawings.

Example 1
1. Composite Electrode First, a composite electrode according to an embodiment of the present invention will be described. In this embodiment, the composite electrode is a differential composite pH composite electrode (uniaxial symmetrical differential pH measurement electrode) that employs a pH glass electrode as the internal electrode of the comparison electrode. That is, the pH composite electrode of the present example includes a glass electrode for measurement and a glass electrode for comparison.

  FIG. 1 is a cross-sectional view of the composite electrode 1 of this embodiment. Moreover, FIG. 2 is sectional drawing of the electrode member 2 of a present Example. The composite electrode 1 is formed in a long bar shape in one direction having an axis as a whole. The composite electrode 1 is normally used by being arranged such that its axial direction is along the vertical direction. Hereinafter, the direction corresponding to the up and down directions in FIGS. 1 and 2 may be described as the up and down direction for the composite electrode 1 and its elements. However, the present invention does not specify any orientation when the composite electrode 1 is used. Absent.

  The composite electrode 1 has an electrode member 2. As shown in FIG. 2, the electrode member 2 is formed long in one direction along the axial direction X connecting the upper base end 2a and the lower tip 2b opposite to the upper base end 2a. It has such a coaxial triple tube structure. That is, the electrode member 2 has a glass first tube (hereinafter also referred to as “inner tube”) 21 whose end portion on the tip end 2 b side in the axial direction X is sealed. The electrode member 2 includes a second glass tube (hereinafter referred to as “central tube”) that surrounds at least a part of the inner tube 21 on the proximal end 2a side in the axial direction X and is sealed at the end 2b side. ”) 22. Further, the electrode member 2 is a third glass tube (hereinafter referred to as “outer tube”) that surrounds at least a part of the central tube 22 on the proximal end 2a side in the axial direction X and is sealed at the distal end 2b side. ”). In this embodiment, the electrode member 2 is arranged so that the axial direction X thereof substantially coincides with the entire axial direction of the composite electrode 1.

  The inner tube 21 is a substantially linear tubular member made of glass having a substantially circular cross section perpendicular to the axial direction X. The inner tube 21 has a small-diameter portion 21a on the base end portion 2a side having a small inner diameter and an outer diameter, and a large-diameter portion 21b on the distal end portion 2b side having an inner diameter and an outer diameter larger than the small-diameter portion 21a. The small diameter portion 21a and the large diameter portion 21b are formed substantially continuously in a coaxial manner. The central tube 22 is a substantially linear tubular member formed of glass having a substantially uniform inner diameter and outer diameter with a substantially circular cross section orthogonal to the axial direction X. The central tube 22 is joined to the inner tube 21 at an end 22a on the distal end portion 2b side in the vicinity of the connecting portion 21c between the small diameter portion 21a and the large diameter portion 21b of the inner tube 21. The outer tube 23 is a substantially linear tubular member made of glass and having a substantially uniform inner diameter and outer diameter with a substantially circular cross section perpendicular to the axial direction X. The outer tube 23 has an end 23 a on the distal end 2 b side joined to a side portion 22 d at the substantially upper and lower sides of the central tube 22.

  The inner tube 21 forms a first storage portion 26 that can store a liquid. The measurement electrode internal liquid S1 is accommodated in the first accommodating portion 26 that is a stepped cylindrical space. Further, the inner tube 21 and the central tube 22 form a second storage portion 27 that can store the liquid. A pH buffer solution is accommodated in the second accommodating portion 27, which is an annular space formed by the inner tube 21 and the central tube 22, as the internal electrode S3 of the comparison electrode. The central tube 22 and the outer tube 23 form a third storage portion 28 that can store the liquid. The third storage portion 28 that is an annular space formed by the central tube 22 and the outer tube 23 stores the comparative glass electrode internal liquid S2. In the present embodiment, the inner tube 21, the central tube 22 and the outer tube 23 are arranged substantially coaxially with respect to the axis X and spaced from each other.

  A measurement glass sensitive film 24 that is a pH glass sensitive film as a measurement sensitive part is provided in a region of the inner pipe 21 that is not surrounded by the central tube 22, particularly in the present embodiment, on the end portion 2 b side of the inner pipe 21. Is provided. The glass sensitive film 24 for measurement is formed in a substantially hemispherical shape protruding downward at the end of the inner tube 21 in the axial direction, and is welded and integrated with the inner tube 21. The measuring glass sensitive film 24 constitutes the bottom of the inner tube 21. Further, a part of the central tube 22 in the axial direction X of the region surrounded by the outer tube 23 is formed by a cylindrical comparative glass sensitive film 25 which is a pH glass sensitive film. The comparative glass sensitive film 25 is fused and integrated with a part of the central tube 22 in the axial direction. In this embodiment, the comparative glass sensitive film 25 has substantially the same inner diameter and outer diameter as the other parts of the central tube 22 and is formed substantially coaxially with the central tube 22. Part of it. In addition, a liquid junction portion 29 that enables electrical connection between the liquid inside and outside the second housing portion 27 is provided in a region of the central tube 22 that is not surrounded by the outer tube 23. The liquid junction 29 is sealed so as to penetrate the central tube 22. In the present embodiment, the liquid junction portion 29 is a substantially columnar (round bar-shaped) member formed of porous ceramic which is an example of a porous member.

  As an example, the dimension of each part of the electrode member 2 of a present Example is as follows in general. In addition, the manufacturing method of the electrode member 2 is mentioned later.

Outer diameter of the small diameter portion 21a of the inner tube 21: 3.05 mm (wall thickness 0.6 mm)
Length in the axial direction X of the small diameter portion 21a of the inner tube 21: 71.4 mm
Outer diameter of the large diameter portion 21b of the inner tube 21: 7.35 mm (wall thickness 0.65 mm)
Length in the axial direction X of the large diameter portion 21b of the inner tube 21 (including the sensitive film): 25 mm
The outer diameter of the central tube 22: 7.35 mm (wall thickness 0.65 mm)
Length of the central tube 22 in the axial direction X: 70.4 mm
Length in the axial direction X of the region not covered by the outer tube 23 of the central tube 22: 31.6 mm
Outer diameter of outer tube 23: 12 mm (wall thickness 1 mm)
Length of the outer tube 23 in the axial direction X: 37.8 mm
Length of axial direction X of glass sensitive film for comparison 25: 7 mm
Distance in the axial direction X from the tip 2b to the liquid junction 29: 35 mm
Distance in the axial direction X from the tip 2b to the comparative glass sensitive film 25: 66.6 mm
Diameter of liquid junction 29: 0.75 mm

  In addition, the composite electrode 1 has a measurement electrode inner electrode 11 that is immersed in the measurement electrode internal liquid S <b> 1 accommodated in the first accommodation part 26. In this embodiment, the measurement electrode inner electrode 11 is a silver / silver chloride electrode. The composite electrode 1 also has a comparative glass electrode inner electrode 12 that is immersed in the comparative glass electrode internal liquid S <b> 2 accommodated in the third accommodating portion 28. In this embodiment, the comparative glass electrode inner electrode 12 is a silver / silver chloride electrode. Leads 14 and 15 are connected to the measurement electrode inner electrode 11 and the comparative glass electrode inner electrode 12, respectively. The base end portion 2a of the electrode member 2 contains the measurement electrode internal liquid S1, the comparative electrode inner internal liquid S3, and the comparative glass electrode internal liquid S2 in the first, second, and third storage portions 26, 27, and 28, respectively. In addition, the measurement electrode inner electrode 11 and the comparative glass electrode inner electrode 12 are arranged in the first and third housing portions 26 and 28 and sealed with the cap 7. After the leads 14 and 15 respectively connected to the measurement electrode inner electrode 11 and the comparative glass electrode inner electrode 12 are extended upward through the first accommodating portion 26 and the third accommodating portion 28, respectively, It is pulled out through the cap 7 and connected to a preamplifier 8 to be described later. In the present embodiment, the cap 7 is a packing made of silicone rubber, and the cap 7 is fixed to the base end portion 2 a of the electrode member 2. This fixing can be performed by any means such as press-fitting, screwing, and bonding. In this embodiment, the fixing is performed after press-fitting. Then, as will be described later, the electrode member 2 whose base end portion 2a is sealed with the cap 7 is disposed inside the outer cylinder 3 and fixed.

  The composite electrode 1 is disposed so as to surround the electrode member 2 along the axial direction X of the electrode member 2, and forms an outer cylinder 3 that forms a fourth storage portion 30 that can store a liquid between the electrode member 2. Have The outer cylinder 3 is a substantially linear tubular member formed of an insulating member (polysulfone resin in the present embodiment) such as resin or plastic having a substantially circular cross section perpendicular to the axial direction of the composite electrode 1. The outer cylinder 3 has an upper circuit housing portion 3b and a lower electrode housing portion 3a having an inner diameter and an outer diameter smaller than the circuit housing portion 3b. The electrode housing portion 3a and the circuit housing portion 3b are formed continuously in a substantially coaxial manner. The electrode member 2 is disposed in the electrode housing portion 3a, and the outer periphery of the cap 7 is fixed to the inner periphery of the upper end of the electrode housing portion 3a, so that the electrode member 2 is fixed inside the outer cylinder 3. The This fixing can be performed by any means such as press-fitting, screwing, and adhesion. In this embodiment, the fixing is formed on the screw portion formed on the outer periphery of the cap 7 and on the inner periphery of the electrode housing portion 3a. The screw part was screwed together and bonded. A preamplifier 8 and a connector 9 are arranged in the circuit housing portion 3 b of the outer cylinder 3. The preamplifier 8 is connected to a pH measuring device (not shown) through a connector 9 by a cable (not shown).

  The composite electrode 1 has a sealing portion 4. The sealing portion 4 seals the opening 3c at the end of the outer cylinder 3 on the tip portion 2b side in the axial direction X of the electrode member 2, and exposes the measurement glass sensitive film 24 of the electrode member 2 to the outside. . The composite electrode 1 has an outer liquid junction portion 5 that is provided in the sealing portion 4 and enables electrical connection between the inner and outer liquids of the fourth housing portion 30. The sealing portion 4 can be formed of any material that can seal the opening 3c of the outer cylinder 3, such as resin, ceramic, rubber, adhesive, glass, or the like. Here, sealing the opening 3c of the outer cylinder 3 means that the liquid stored in the fourth storage unit 30 leaks unreasonably in a state where the composite electrode 1 is not immersed in the test solution. To close so that there is no. In the present embodiment, the sealing portion 4 is formed of a porous resin that is an example of a porous member that itself functions as a liquid junction. Specifically, in the present embodiment, the sealing portion 4 has a through-hole 4a through which the distal end portion 2b of the electrode member 2 is inserted while sealing the opening 3c at the end of the outer cylinder 3. It is made into a member. The sealing portion 4 is detachable from the outer cylinder 3 along the axial direction of the outer cylinder 3. In the present embodiment, the sealing portion 4 is detachable by screwing the screw portion formed on the outer peripheral surface thereof to the screw portion formed on the inner peripheral surface in the vicinity of the opening 3 c of the outer cylinder 3. Fixed. This fixing may be performed by other arbitrary methods such as press fitting and snap fitting. The sealing part 4 includes an O-ring (outer O-ring) 4b as a sealing member for liquid-tight sealing between the outer cylinder 3 and the sealing part 4, and a gap between the electrode member 2 and the sealing part 4. An O-ring (inner O-ring) 4c is provided as a sealing member that seals liquid-tightly. The glass-sensitive film for measurement 24 at the distal end portion 2 b of the electrode member 2 is exposed to the outside of the sealing portion 4. And the outer liquid junction part 5 is embedded in the sealing part 4 so that this sealing part 4 may be penetrated. In the present embodiment, the outer liquid junction portion 5 is a substantially cylindrical (round bar-shaped) member formed of porous ceramic which is an example of a porous member.

  The fourth electrode 30 that is a tubular space formed by the electrode member 2 and the outer cylinder 3 stores the reference electrode outer internal liquid S4. In this embodiment, since the sealing portion 4 is detachable from the outer cylinder 3, the reference electrode outside internal liquid S4 can be replaced or supplemented by removing the sealing portion 4. Moreover, the sealing part 4 (and the outer liquid junction part 5 attached to this) can also be replaced.

  In addition, the composite electrode 1 is fitted and attached from the outside so as to surround a predetermined range on the lower end side of the outer cylinder 3 and functions as a common liquid earth electrode in differential measurement. Have In this embodiment, the ground tube 6 is a substantially straight line made of metal (titanium in this embodiment) having a substantially uniform inner diameter and outer diameter, with a cross section orthogonal to the axial direction of the composite electrode 1 being substantially circular. This is a tubular member. In the present embodiment, the ground tube 6 extends below the lower end of the opening 3c of the outer cylinder 3 (more specifically, the sealing portion 4 attached thereto). It reaches below the end of the glass sensitive film 24 for measurement. Thereby, the ground pipe 6 also functions as a protective member for the glass sensitive film 24 for measurement. A plurality of notches 6b are formed in the edge 6a at the lower end of the gland tube 6 to promote the flow of the test solution to the glass sensitive film 24 for measurement.

  The composite electrode 1 has a body 10 that covers the outer cylinder 3. The body 10 is attached so as to cover from the outside to a predetermined range above the ground pipe 6 from above the upper end of the outer cylinder 3. The body 10 protects the internal structure of the body 10 and provides a grip when the user operates the composite electrode 1. On the outer periphery of the upper end portion of the ground tube 6, an O-ring 6 c is provided as a seal member that seals between the ground tube 6 and the body 10 in a liquid-tight manner. Further, a temperature sensor 13 is provided in a gap between the body 10 and the outer cylinder 3 above the O-ring 6c. Further, the leads 16 and 17 connected to the temperature sensor 13 and the ground pipe 6 are extended upward through the gap between the body 10 and the outer cylinder 3, so that the inside of the circuit accommodating portion 3 b of the outer cylinder 3 Connected to the preamplifier 8.

  In the present embodiment, a measurement pH glass electrode (measurement electrode M) is formed by the measurement glass sensitive film 24, the first housing portion 26, the measurement electrode internal liquid S1, the measurement electrode inner electrode 11, and the like.

  On the other hand, a comparative pH glass electrode is formed by the comparative glass sensitive film 25, the third accommodating portion 28, the comparative glass electrode internal liquid S2, the comparative glass electrode inner electrode 12, and the like. Furthermore, using this comparative pH glass electrode as an internal electrode, the second storage part 27 (and the internal electrode S1 inside the comparison electrode) and the liquid junction part 29, and the fourth storage part 30 (and the internal part thereof) The reference electrode outer internal liquid S4), the outer liquid junction part 5 and the sealing part 4 constitute a double junction type reference electrode R. That is, the comparative pH glass electrode is immersed in the internal liquid (pH buffer solution) S3 inside the comparative electrode in the second housing portion 27 and functions as the internal electrode of the comparative electrode R. The comparative pH glass electrode includes a comparison electrode inner internal liquid S3, a liquid junction part 29, a comparison electrode outer internal liquid S4 in the fourth storage part 30, and an outer liquid junction. It is electrically connected to the test solution via the part 5 (further sealed part 4 in this embodiment). More specifically, the reference electrode inner internal liquid S3 in the second storage part 27 oozes out through the liquid junction part 29 to the comparison electrode outer internal liquid S4 in the fourth storage part 30, and this fourth storage. The reference electrode outer internal liquid S4 in the part 30 oozes out to the test liquid through the outer liquid junction part 5 (further, the sealing part 4 in this embodiment). As a result, the comparative glass electrode inner electrode 12 and the test solution are electrically connected. That is, the reference electrode R has a double junction structure having the outer liquid junction portion 5 and the liquid junction portion 29.

  The measurement electrode M generates a potential corresponding to the pH of the test liquid, and the comparison electrode R is the pH of the inner liquid S3 inside the comparison electrode (and the inter-liquid occurrence occurring at the contact interface between the outer liquid junction 5 and the test liquid). A potential corresponding to (electric power) is generated. Then, using the ground tube 6 as a common liquid earth electrode, the potential difference between the measurement electrode M and the ground tube 6 and the potential difference between the comparison electrode R and the ground tube 6 are measured, and the potential of the ground tube 6 is cancelled. Thus, the potential difference between the measurement electrode M and the comparison electrode R is obtained, and the pH value of the test solution is obtained from this potential difference.

  Here, in this example, a pH 7.0 pH buffer solution (phosphate buffer solution) was used as the measurement electrode internal solution S1. Further, a pH buffer solution (phosphate buffer solution) having a pH of 7.0 was used as the comparative glass electrode internal solution S2. Further, a pH buffer solution (phosphate buffer solution) having a pH of 7.0 was used as the reference electrode inner internal solution S3. Further, potassium chloride (KCl) is generally used as a component of the reference electrode outer internal liquid S4. In particular, a high concentration (3 mol to saturated) KCl solution is often used. In this example, a saturated KCl solution was used as the reference electrode outer internal solution S4. These internal liquids may be made into a gel or sol form by adding a thickener, if desired. Here, exuding the internal liquid through the liquid junction includes both flowing out the internal liquid as a solution and flowing out (diffusing) only the component.

  The porous ceramic material constituting the liquid junction includes various ceramics such as alumina, cerium, magnesia, and zirconia depending on the ceramic composition. Ceramic was used. Moreover, as a material of the porous resin constituting the sealing part 4 having the function of the liquid junction part, a fluororesin, a polyethylene resin, or a polypropylene resin can be used. Examples of the fluororesin include PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene propene copolymer), ETFE (ethylene-tetrafluoroethylene copolymer), and the like. In this example, PTFE was used. In this embodiment, the sealing portion 4 is made of a porous resin to have the function of a liquid junction portion, and the outer liquid junction portion 5 made of porous ceramic is separately attached. By adopting such a hybrid liquid junction, while maintaining the predetermined performance of the liquid junction by a porous ceramic with a more uniform porosity and pore diameter, the liquid contact area as a whole of the liquid junction is increased by the porous resin. There is an advantage that the life is extended. However, the present invention is not limited to such a configuration. For example, the sealing portion 4 is formed of a resin or plastic that does not have the function of a liquid junction portion instead of the porous resin in this embodiment, or sealed. The stop 4 may be formed of an adhesive or glass that is fixedly provided to the outer cylinder 3. Further, the sealing portion 4 may be formed of a material having a function of a liquid junction such as a porous resin, and the outer liquid junction 5 of the porous ceramic may not be attached separately. Also in this case, it can be said that the liquid junction part is provided in the sealing part 4. Further, the liquid junction portion 29 provided in the electrode member 2 is not limited to a ceramic type in which a porous ceramic is enclosed in a glass tube, and a through-hole provided in a glass tube well known in the art. A fiber type (FIG. 3 (a)) in which one or a plurality of fibers (glass fiber, crystal fiber, etc.) 29a are sealed in, and a pinhole type (FIG. 3) in which a small hole 29b is formed in a glass tube by high-pressure discharge or the like. (B)) may be used.

2. Next, the manufacturing method of the electrode member 2 in a present Example is demonstrated. 4-6 is a schematic diagram which shows the state of the member in each process in the manufacturing method of the electrode member 2 in a present Example.

  First, as shown in FIG. 4 (a), a part A that is the basis of the central tube 22 is a glass stem tube (support tube) having a predetermined inner diameter and outer diameter corresponding to the central tube 22, and a predetermined length. Cut into pieces.

  Next, as shown in FIG. 4B, a glass film type (molten glass) m of the comparative glass sensitive film 25 is adhered so as to seal one end of the part A, and the part A1 is attached. Make it. The method itself for attaching the glass film species is the same as the method for producing a general hemispherical or spherical glass-sensitive film. For example, a crucible containing a glass film seed m is placed in a furnace (such as an electric furnace), and the temperature inside the furnace is adjusted to an appropriate temperature while heating the part A, for example, at an appropriate speed from above in the glass film seed m. Soaked in a glass, held for an appropriate time, and then pulled up at an appropriate speed. Thereby, an appropriate amount of the glass film seed m is adhered to one end of the part A.

  Next, as shown in FIGS. 4 (c) and 4 (d), air is blown into the part A1 where the glass film seed m adheres to one end from the other end, and the glass adheres to the one end. Blow off the film seed m to produce part A2. At this time, the blown glass film seed m forms a sufficient opening and is in a state of being attached substantially uniformly in the circumferential direction.

  Next, as shown in FIG. 4D, the blown glass film seeds m of the two parts A2 to which the blown glass film seeds m adhere to the ends are joined together, and FIG. ), The glass film seed m is formed into a cylindrical shape to produce a part A2A2. In this embodiment, the part A2A2 is a glass tubular member having a cylindrical comparative glass sensitive film 25 in a part in the axial direction.

  Next, as shown in FIG. 4 (f), one end of the part A2A2 is flared to join another part in a later step, thereby producing the part AA.

On the other hand, the part B (end tubular member) that is the basis of the large-diameter portion 21b of the inner tube 21 shown in FIG. 5A is the part C that is the basis of the small-diameter portion 21a of the inner tube 21 shown in FIG. (Small-diameter tubular member) A part D that forms the basis of the outer tube shown in FIG. The method for producing the part B shown in FIG. 5A is the same as the method for producing a general hemispherical or spherical glass-sensitive film. That is, in the same manner as when the part A1 is produced at one end of a glass stem tube having a predetermined inner diameter and outer diameter corresponding to the large diameter portion 21b of the inner tube 21 and cut into a predetermined length. The glass sensitive film 24 for measurement is adhered, and air is blown into the stem tube to expand it into a hemispherical shape or a spherical shape (in this embodiment, a hemispherical shape), thereby forming the measuring glass sensitive film 24. 5B, a glass stem tube having a predetermined inner diameter and outer diameter corresponding to the small diameter portion 21a of the inner tube 21 is cut into a predetermined length, and one end portion is flared. It is a thing. A part D (large-diameter tubular member) shown in FIG. 5C is obtained by cutting a glass stem tube having a predetermined inner diameter and an outer diameter corresponding to the outer tube 23 into a predetermined length.

  Then, as shown in FIG. 6, the parts AA, B, C, and D are assembled into the electrode member 2. The left side in FIG. 6 corresponds to the base end 2a of the electrode member 2 and the right side corresponds to the front end 2b of the electrode member 2, so here the left side in FIG. Sometimes called a department.

First, as shown in FIG. 6A, the part AA is arranged inside the part D, and the flared tip part of the part AA and the tip part of the part D are welded and joined together, and the part AAD (First part) is produced. Thereby, the part AA and the part D are integrated, and the 3rd accommodating part 28 is formed.

Next, as shown in FIG. 6 (b), the distal end portion where the part AAD is opened and the proximal end portion where the part B is opened are welded and joined to produce a part AADB (second part) . . Thereby, the part AAD and the part B are integrated, and the inside of the part AA in the part AAD communicates with the inside of the part B.

Next, as shown in FIG. 6C, the part C is placed inside the part AA in the part AADB, and the flared tip of the part C is welded to a predetermined position of the part B in the part AADB. To make part AADBC (third part) . Thereby, the parts AADB and the parts C are integrated to form the first housing part 26 and the second housing part 27.

  Next, as shown in FIG. 6D, the liquid junction 29 is sealed on the side of the part B in the part AADBC. Note that the liquid junction 29 may be sealed in advance in the state of the part B shown in FIG. 5A or the state of the part AADB shown in FIG.

  Thus, the electrode member 2 is manufactured. In addition, joining of parts in each of the above steps, sealing of a liquid junction, or forming of a cylindrical comparative glass-sensitive film itself can be performed in the manner of glasswork using a Bunsen burner, for example.

  In addition, the following method is mentioned as another example of the method of producing the glass-made tubular member which has a cylindrical comparative glass sensitive film | membrane in a part of axial direction. First, as shown in FIG. 7A, a tubular member (also referred to as a “sensitive membrane tube”) is prepared in advance using the glass constituting the comparative glass sensitive membrane. This sensitive membrane tube can be made longer than the length of the comparative glass sensitive membrane in the electrode member 2 in the axial direction, and can be cut into a predetermined length for use. Then, as shown in FIG. 7B, glass stem tubes are welded and joined to both ends of the sensitive membrane tube.

  As described above, according to the present embodiment, the electrode member 2 includes the main components of the composite electrode in which the glass electrode is adopted as the internal electrode of the comparison electrode, that is, the measurement glass sensitive film 24, the comparative glass sensitive film 25, and the liquid. The entanglement portion 29 and the first to third accommodation portions 26, 27, and 28 are integrally configured to have a simple structure. Therefore, the electrode member 2 and the composite electrode 1 can be reduced in size. Further, since the structure of such main constituent elements is simple, durability and reliability can be improved. Moreover, since this composite electrode 1 does not form an “electrode chamber” and a “salt bridge chamber” using many packings and liquid junctions as in the case of the above-described conventional technology, Liquid leakage is unlikely to occur. Further, as described above, the electrode member 2 having a simple structure can be manufactured by applying a general glassworking technique to those skilled in the art if the disclosure of the present invention is disclosed. Can be easily manufactured.

Example 2
Next, another embodiment according to the present invention will be described. The basic configuration of the composite electrode in the present embodiment is the same as that of the first embodiment. Therefore, elements having the same configuration or function as those of the first embodiment or corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, the arrangement of the liquid junction portion 29 in the electrode member 2 and the arrangement of the comparative glass electrode inner electrode 12 in the composite electrode 1 are mainly different from those in the first embodiment.

  FIG. 8 is a cross-sectional view of the electrode member 2 of the present embodiment. In this embodiment, the electrode member 2 has the same triple tube structure as that of the first embodiment. That is, a measurement glass sensitive film 24 that is a pH glass sensitive film is provided at the end of the inner tube 21 on the distal end 2b side, and a part of the region surrounded by the outer tube 23 of the central tube 22 is a pH glass sensitive film. It is formed by the cylindrical comparative glass sensitive film | membrane 25 which is. However, in this embodiment, unlike the first embodiment, the liquid junction 29 is provided in the outer tube 23. In the present embodiment, the liquid junction portion 29 is provided in the vicinity of the joint portion between the outer tube 23 and the central tube 22. The liquid junction portion 29 enables electrical connection between the liquid inside and outside the third housing portion 28 formed by the outer tube 23 and the inner tube 22. In the present embodiment, the measurement glass sensitive film 24 is formed in a substantially spherical shape. Further, in the present embodiment, the outer tube 23 has an end 23 a on the distal end 2 b side joined to a side 22 d slightly below the center of the central tube 22 in the vertical direction.

  As an example, the dimension of each part of the electrode member 2 of a present Example is as follows in general. In addition, the manufacturing method of the electrode member 2 is mentioned later.

Outer diameter of the small diameter portion 21a of the inner tube 21: 3.8 mm (thickness 0.6 mm)
Length in the axial direction X of the small diameter portion 21a of the inner tube 21: 75.5 mm
Outer diameter of the large diameter part 21b of the inner tube 21: 8.15 mm (wall thickness 0.65 mm)
Length in the axial direction X of the large diameter portion 21b of the inner tube 21 (including the sensitive film): 20mm
The outer diameter of the central tube 22: 7.35 mm (wall thickness 0.65 mm)
The length of the central tube 22 in the axial direction: 73.5 mm
Length in the axial direction X of the region not covered with the outer tube 23 of the central tube 22: 20 mm
Outer diameter of outer tube 23: 12 mm (wall thickness 1 mm)
Length in the axial direction X of the outer tube 23: 53.5 mm
Length of the glass sensitive film for comparison 25 in the axial direction X: 4 mm
Distance in the axial direction X from the tip 2b to the liquid junction 29: 50 mm
Distance in the axial direction X from the tip 2b to the comparative glass sensitive film 25: 63 mm
Diameter of liquid junction 29: 0.75 mm

  In this embodiment, the measurement electrode internal liquid S1 is stored in the first storage portion 26, and the measurement electrode inner electrode 11 is immersed in the measurement electrode internal liquid S1. Further, the comparative glass electrode internal liquid S2 is stored in the second storage portion 27, and the comparative glass electrode inner electrode 12 is immersed in the comparative glass electrode internal liquid S2. Then, the reference electrode inner liquid S <b> 3 is accommodated in the third accommodating portion 28.

  In the present embodiment, a measurement pH glass electrode (measurement electrode M) is formed by the measurement glass sensitive film 24, the first housing portion 26, the measurement electrode internal liquid S1, the measurement electrode inner electrode 11, and the like. On the other hand, a comparative pH glass electrode is formed by the comparative glass sensitive film 25, the second accommodating portion 27, the comparative glass electrode internal liquid S2, the comparative glass electrode inner electrode 12, and the like. Further, with this comparative pH glass electrode as an inner pole, the third housing part 28 (and the internal liquid S3 inside the comparison electrode inside it), the liquid junction part 29, the fourth housing part 30 (and the inside comparison). A double junction type comparison electrode R is constituted by the electrode outer internal liquid S4), the outer liquid junction part 5 and the sealing part 4 (see FIG. 1). That is, the comparative pH glass electrode is immersed in the internal liquid (pH buffer solution) S3 inside the comparative electrode in the third housing portion 28 and functions as the internal electrode of the comparative electrode R. The comparative pH glass electrode includes a comparison electrode inner internal liquid S3, a liquid junction part 29, a comparison electrode outer internal liquid S4 in the fourth storage part 30, and an outer liquid junction. It is electrically connected to the test solution via the part 5 (further sealed part 4 in this embodiment). More specifically, the reference electrode inner internal liquid S3 in the third storage portion 28 oozes out through the liquid junction portion 29 to the comparison electrode outer internal liquid S4 in the fourth storage portion 30, and this fourth storage. The reference electrode outer internal liquid S4 in the part 30 oozes out to the test liquid through the outer liquid junction part 5 (further, the sealing part 4 in this embodiment). As a result, the comparative glass electrode inner electrode 12 and the test solution are electrically connected.

  Thus, even when the electrode member 2 of this embodiment is used, pH measurement can be performed in the same manner as in the first embodiment.

  Further, the electrode member 2 of the present embodiment can be manufactured by a manufacturing method substantially similar to that described in the first embodiment except that the arrangement of the liquid junction portion 29 is different.

  As described above, according to the present embodiment, as in the first embodiment, the configuration of the electrode member 2 is simplified, the electrode member 2 and the composite electrode 1 are downsized, the durability is improved, the reliability is improved, and the manufacturing is facilitated. Can be achieved.

  Here, in general, the liquid junction member 29 of the electrode member 2 is desirably provided below the gravitational direction in a normal use state. This is because even if the internal liquid is reduced, the state where the liquid junction 29 is immersed in the internal liquid can be maintained for a longer period of time, and the life and service period (maintenance is required for the composite electrode). This is because it is advantageous in terms of the period until. In this regard, in the case where the liquid junction portion 29 is provided in the central tube 22 as in the first embodiment, the liquid junction portion 29 is provided in a portion obtained by extending the central tube 22 narrower than the outer tube 23 downward, The liquid junction 29 can be provided further downward while suppressing the increase in size (increase in diameter) of the electrode member 2 and the composite electrode 1. On the other hand, when the liquid junction 29 is provided on the outer tube 23 as in the present embodiment, if the liquid junction 29 is to be provided further downward, the outer tube 23 thicker than the central tube 22 is formed. It has to be extended downward, and the volume of the fourth housing part 30 is reduced, or the composite electrode is enlarged (increased in diameter) in order to suppress the reduction of the volume. From this viewpoint, it can be said that the structure of Example 1 is more preferable.

Others While the present invention has been described with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

  In the above-described embodiments, the case where the present invention is applied to a sensor for pH measurement has been described as an example. However, the present invention is not limited to this, and an electrode member used in electrochemical measurement using a comparative electrode. The present invention can be widely applied to a composite electrode including the electrode member. Examples of the electrochemical measurement sensor using the reference electrode include pH measurement, various ion concentration measurement sensors for measuring various ion concentrations, and oxidation-reduction potential (ORP) measurement sensors. The present invention can be applied to any of these sensors.

  When the present invention is applied to an ion concentration measurement sensor for measuring ion concentrations other than hydrogen ions, the glass sensitive film for measurement as the measurement sensitive part in the above-described embodiment is used as the glass sensitive film sensitive to the measurement target ion. Instead, a corresponding measurement electrode internal solution may be used. Also, for example, in the case of adapting to ion measurement using a hardly soluble silver salt as a sensitive substance, silver is plated on the surface of a platinum electrode encapsulated in glass, and further chlorinated to form a silver-silver chloride film. It is possible to apply a method of applying a slightly soluble silver salt powder of a desired sensitive substance in a silicone rubber matrix. In addition, for example, in the case of application to ion measurement using a liquid film as a sensitive substance, the surface of a platinum electrode enclosed in glass is plated with silver and further chlorinated to form a silver-silver chloride film, where PVC is formed. A method of attaching a desired sensitive substance matrixed on (polyvinyl chloride) becomes possible. In addition, when the present invention is applied to a sensor for measuring the oxidation-reduction potential, as shown in FIG. 9, a measurement-use glass sensitive film as a measurement-sensitive part in the above-described embodiment is a metal electrode ( Instead of the platinum electrode, the gold electrode, etc.) 40, the lead 41 connected to the metal electrode may be passed through the first accommodating portion 26 without accommodating the liquid inside the measurement electrode.

  In the above-described embodiments, the case where a glass film sensitive to pH is used as the comparative glass sensitive film has been described as an example, but the present invention is not limited to this, and other ion sensitive glass films are used. Can be used. For example, the comparative glass sensitive film can be a sodium ion sensitive film. In this case, the internal solution for the glass electrode for comparison may be a sodium ion-containing solution containing sodium ions having a predetermined concentration, and the internal solution for the reference electrode and the internal solution for the outside of the reference electrode may each be a potassium chloride (KCl) solution.

DESCRIPTION OF SYMBOLS 1 Composite electrode 2 Electrode member 3 Outer cylinder 4 Sealing part 5 Outer liquid junction 6 Ground tube 11 Measuring electrode inner electrode 12 Glass electrode inner electrode 21 for comparison 21 Inner tube (first tube)
22 Central pipe (second pipe)
23 Outer pipe (third pipe)
24 Glass sensitive film for measurement 25 Glass sensitive film for comparison 29 Liquid junction S1 Measurement electrode internal liquid S2 Comparative glass electrode internal liquid S3 Comparative electrode inner internal liquid S4 Comparative electrode outer internal liquid

Claims (8)

An electrode member used for a composite electrode comprising a measurement electrode and a comparative electrode, wherein the internal electrode of the comparative electrode is a glass electrode ,
A first tube made of glass that is elongated in the axial direction and sealed at the end on the tip side;
Is熔着 sealed at least in part surrounds the distal end side tube end the first of the opposite side of the base end side to the tip side of the first tube in the axial direction A second glass tube,
A third glass tube that surrounds at least a part of the base end side of the second pipe in the axial direction and is sealed by being welded to the end of the end side of the second pipe. When,
Have
The first tube, the second tube, and the third tube constitute a triple tube structure arranged substantially coaxially,
Before SL said second measurement in enclosed non regions to the tube titration, glass-sensitive film is provided in the first tube,
First storage portion for storing the first measuring electrode in electrode is immersed in the measuring electrode internal solution and the measuring electrode inner liquid by the tube is formed,
Before SL and the third region surrounded by the tube of the axial part a tubular comparative glass-sensitive film of the second tube are integrated is熔着,
The second housing part is formed for accommodating the O Ri comparisons electrode inside internal solution in said second tube and said first tube,
Third receiving portion formed for accommodating the second tube and the third tube and the O Ri ratio較用glass electrode internal solution and the comparative glass electrode in electrode is immersed in the comparative glass electrode internal liquid And
In the region of the second tube that is not surrounded by the third tube, a liquid junction that enables electrical connection between the liquid inside and outside the second storage unit is enclosed,
The measurement electrode is configured to include the measurement glass-sensitive film, the first accommodating portion, the measurement electrode internal liquid, and the measurement electrode inner electrode,
The comparative electrode includes the comparative glass sensitive film, the second accommodating portion, the comparative electrode inner internal liquid, the third accommodating portion, the comparative glass electrode internal liquid, and the comparative glass. An electrode member comprising an electrode inner electrode and the liquid junction . The electrode member according to claim 1 , wherein the comparative glass sensitive film is a pH glass sensitive film. The measuring glass-sensitive film, the electrode member according to claim 1 or 2, characterized in that the pH glass-sensitive film. A composite electrode comprising a measurement electrode and a comparative electrode, wherein the internal electrode of the comparative electrode is a glass electrode,
A first tube made of glass which is formed in a long axis in the axial direction and whose first end is sealed to store a measurement electrode internal liquid , and the first tube in the axial direction. said first tube being熔着to at least an end portion of the part surrounding the tip side of the first tube opposite the base end side is sealed and the front end portion of the first tube comparison and glass second tube electrodes inside internal solution to form a second housing part that will be housed, at least a portion of the proximal end of the second tube in the axial direction between the end of the front end portion forms a third housing portion comparative glass electrode internal liquid Ru housed between the second is the熔着the tubes sealed with the second tube surrounds a third tube made of glass, the said first tube, said second tube and said third tube disposed substantially coaxially three Constitute the tubular structure, wherein the first said in the tube second measurement the enclosed non regions to the tube titration, glass sensing film is formed, surrounded by the third tube in the second tube region wherein a portion of the axial direction the tubular comparative glass-sensitive film are integrated is熔着, area before Symbol second not surrounded by said third tube in the second tube An electrode member in which a liquid junction that enables electrical connection between liquids inside and outside the housing portion is enclosed ;
A measurement electrode inner electrode disposed in the first housing part so as to be immersed in the measurement electrode internal liquid housed in the first housing part;
A comparative glass electrode inner electrode arranged in the third housing part so as to be immersed in the liquid in the comparative glass electrode housed in the third housing part;
An outer cylinder forming the in the axial direction are disposed surrounding the electrode member, the fourth housing part reference electrode outside the internal fluid Ru housed between the electrode member,
A sealing portion that seals the opening of the end portion of the outer cylinder on the tip end side in the axial direction and exposes the glass-sensitive film for measurement to the outside;
An outer liquid junction that is provided in the sealing portion and enables electrical connection between liquids inside and outside the fourth housing portion;
Have
The measuring electrode, the measurement for the glass-sensitive film, said first housing portion, wherein the measuring electrode internal liquid, the measurement electrode in the electrode, the configured Nde including,
The comparative electrode includes the comparative glass sensitive film, the second accommodating portion, the comparative electrode inner internal liquid, the third accommodating portion, the comparative glass electrode internal liquid, and the comparative glass. and the electrode inner electrode, and the liquid junction, the fourth receiving portion, and the reference electrode outside the internal liquid, a composite electrode wherein the outer liquid junction, the characterized in that it is configured Nde free. 5. The composite electrode according to claim 4 , wherein the comparative glass sensitive film is a pH glass sensitive film. Before SL measuring glass-sensitive film, the composite electrode according to claim 4 or 5, characterized in that a pH glass-sensitive film. Furthermore, it arranged to surround the outer cylinder, according to any one of claims 4-6, characterized in that it has a tubular member constituting a common liquid earth electrode of the measuring electrode and the reference electrode Composite electrode. A method for producing an electrode member comprising a measurement electrode and a comparative electrode, and used for a composite electrode in which the internal electrode of the comparative electrode is a glass electrode,
A step of attaching a glass film type of a glass sensitive film so as to seal an end of a glass stem tube;
Blowing the air into the stem tube with the glass film seed attached to the end portion and blowing the glass film seed attached to the end portion of the stem tube; and
The blown glass film seeds of the two stem tubes having the blown glass film seeds attached to the end portions are joined to each other, and the reference electrode is configured in a part of the axial direction. A step of producing a glass tubular member in which a cylindrical glass-sensitive film is fused and integrated ;
The tubular member is disposed inside a large-diameter tubular member formed of a glass stem tube having a larger diameter than the tubular member, and one end of the tubular member and one end of the large-diameter tubular member are welded together And producing a first part of a double-pipe structure in which the one end of the tubular member is opened and the one end of the large-diameter tubular member is sealed;
The open end of the tubular member in the first part is an end tubular member formed of a glass stem tube, wherein one end is opened and the other end is sealed, and the measurement electrode The end of the end tubular member provided with the glass-sensitive film for measurement that constitutes the second end is welded so that the inside of the tubular member and the end of the end tubular member communicate with each other. The process of making parts of
A small-diameter tubular member formed of a glass stem tube having a smaller diameter than the tubular member is disposed inside the tubular member and the end tubular member in the second part, and one end of the small-diameter tubular member is The end tubular member in the second part communicates with the inside of the small-diameter tubular member and a portion of the sealed end of the end tubular member in the second part. Producing a third part of the triple-pipe structure by welding;
Before the step of producing the second part, after the step of producing the second part and before the step of producing the third part, or after the step of producing the third part, In the axial direction of the end tubular member, the position between the welded portion of the first part and the end tubular member and the welded portion of the small diameter tubular member and the end tubular member Enclosing a liquid junction that enables electrical connection between the liquid inside and outside the end tubular member in the end tubular member;
A method for producing an electrode member, comprising:

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