阅读说明：本技术 玻璃电极及液质测定装置 (Glass electrode and liquid quality measuring device ) 是由 雨宫秀行 鸟越义明 佐久间秋穗 大须贺淳 于 2018-06-11 设计创作，主要内容包括：玻璃电极(2)是能够测定被检测液体的阳离子浓度的玻璃电极。玻璃电极(2)具备：平坦的感应玻璃体(2a),其具有离子感应性；基体(2b),其由收纳内部液体(S1)的玻璃管形成；以及固着层(2c2),其使感应玻璃体(2a)封接于基体(2b)的端面(2b1)。固着层(2c2)的电阻值(R2c2)为感应玻璃体(2a)的电阻值(Ra)以上。液质测定装置(51)具备该玻璃电极(2)。(The glass electrode (2) is a glass electrode capable of measuring the cation concentration of the liquid to be detected. The glass electrode (2) is provided with: a flat inductive glass body (2a) having ion-inductivity; a base (2b) formed of a glass tube that houses an internal liquid (S1); and a fixing layer (2c2) for sealing the sensing glass body (2a) to the end face (2b1) of the base body (2 b). The resistance value (R2c2) of the anchor layer (2c2) is equal to or greater than the resistance value (Ra) of the sensing glass body (2 a). The liquid quality measuring device (51) is provided with the glass electrode (2).)

1. A glass electrode is characterized by comprising:

a flat sensing glass body having ion sensitivity;

a base body formed of a glass tube that accommodates an internal liquid; and

a fixing layer for sealing the induction glass body to the end face of the base body,

the glass electrode can measure the cation concentration of the detected liquid,

the resistance value of the fixation layer is more than that of the induction glass body.

2. The glass electrode according to claim 1, wherein the sensing glass body has hydrogen ion sensitivity.

3. A liquid measuring apparatus comprises a glass electrode and a liquid receiving section to be detected,

the glass electrode is provided with:

a flat sensing glass body having ion sensitivity;

a base body formed of a glass tube that accommodates an internal liquid; and

a fixing layer for sealing the induction glass body to an end face of the base body,

the bottom of the liquid receiving part to be detected is planar and is provided with a concave part for receiving the liquid to be detected,

the liquid quality measuring device measures the cation concentration of the detected liquid,

the sensing glass body is exposed at the bottom without a step.

4. The liquid quality measurement device according to claim 3, wherein the resistance value of the anchor layer is equal to or greater than the resistance value of the sensing glass body.

5. The liquid mass measurement device according to claim 3 or 4, wherein the sensing glass body has hydrogen ion sensitivity.

6. A liquid quality measuring apparatus is characterized by comprising a glass electrode and a computing unit,

the glass electrode has: a flat sensing glass body having ion sensitivity; a base body formed of a glass tube that accommodates an internal liquid; and a fixing layer for sealing the induction glass body to the end face of the base body,

the computing unit corrects the cation concentration of the liquid to be detected obtained based on the potential of the glass electrode by a correction value based on the resistance values of the sensing glass body and the fixing layer, and outputs the corrected cation concentration as a measured value,

the liquid quality measuring device measures the cation concentration of the liquid to be detected.

7. The liquid quality measurement device according to claim 6, wherein the resistance value of the anchor layer is equal to or greater than the resistance value of the sensing glass body.

8. The liquid mass measurement device according to claim 6 or claim 7, wherein the sensing glass body has hydrogen ion sensitivity.

Technical Field

The present invention relates to a glass electrode and a liquid quality measuring apparatus, and more particularly to a glass electrode having a sensing glass body such as a glass film having ion sensitivity and a liquid quality measuring apparatus for measuring a cation concentration of a liquid to be detected using the glass electrode.

Background

A liquid quality measuring apparatus is known which measures the cation concentration of a liquid to be measured using a glass electrode as a measuring electrode, wherein the glass electrode includes a glass film having ion sensitivity as a sensing glass body.

For example, there is a pH measuring apparatus that measures pH using a glass electrode having a glass film that induces hydrogen ions.

An example of a glass electrode for measuring pH used in a pH measuring apparatus is described in patent document 1.

As described in patent document 1, the glass electrode is in the form of a straight rod having a glass film at the tip end in appearance, and the glass film at the tip end of the inductor is formed to protrude as a thin film in the form of a hemispherical shell or a partial spherical shell.

When the glass electrode is used, the liquid to be detected added to the container is measured by immersing the distal end side having the glass film in the liquid to be detected.

Disclosure of Invention

Problems to be solved by the invention

In a conventional method for forming a glass film as a susceptor in a glass electrode, glass having a predetermined composition, which is a raw material of the glass film, is first melted. Then, the tip of the glass tube serving as the base body is brought into contact with the molten glass, and the molten glass is fused. Then, air is blown from the other end side of the glass tube to expand the glass to be fused into a predetermined shape such as a hemispherical shell shape or a partial spherical shell shape.

In this forming method, when a plurality of glass electrodes are manufactured, it is difficult to make the thickness and shape of the glass film uniform, and it is not suitable for mass production, and the cost is also increased.

Further, since the glass film at the tip portion is formed to protrude thinly in a hemispherical shell shape or a partial spherical shell shape, careful handling is required at the time of measurement and at the time of cleaning after the measurement.

In this way, the conventional glass electrode is desired to be improved in view of the resistance to damage and the ease of handling.

These points to be improved are not limited to the glass electrode for measuring pH, and are also pointed out in the same manner for other glass electrodes for measuring cation concentration.

Accordingly, an object of the present invention is to provide a glass electrode and a liquid quality measuring apparatus which are not easily broken and easily handled, and which can improve production efficiency and reduce cost.

Means for solving the problems

The glass electrode according to the first aspect of the present invention is a glass electrode capable of measuring a cation concentration of a liquid to be detected. The glass electrode is provided with: a flat sensing glass body having ion sensitivity; a base body formed of a glass tube that accommodates an internal liquid; and a fixing layer for sealing the induction glass body to the end face of the base body. The resistance value of the adhesive layer is more than that of the sensing glass body.

The sensing glass body may have hydrogen ion sensitivity.

A liquid quality measurement device according to a second aspect of the present invention is a liquid quality measurement device that measures a cation concentration of a liquid to be detected. The liquid quality measuring apparatus includes a glass electrode and a liquid receiving unit to be detected, the glass electrode includes: a flat sensing glass body having ion sensitivity; a base body formed of a glass tube that accommodates an internal liquid; and a fixing layer for sealing the sensing glass body to the end face of the base body, wherein the bottom of the liquid receiving portion to be detected is planar and has a recess for receiving the liquid to be detected. The sensing glass body is exposed at the bottom of the recess without a step.

A liquid mass measuring apparatus according to a third aspect of the present invention is a liquid mass measuring apparatus for measuring a cation concentration of a liquid to be detected. The liquid quality measuring apparatus includes a glass electrode and a computing unit, the glass electrode includes: a flat sensing glass body having ion sensitivity; a base body formed of a glass tube that accommodates an internal liquid; and an anchor layer sealing the sensing glass body to an end face of the base, wherein the computing unit corrects the cation concentration of the liquid to be detected obtained based on the potential of the glass electrode with a correction value based on the resistance values of the sensing glass body and the anchor layer, and outputs the correction value as a measured value.

In the liquid mass measurement device according to the second or third aspect of the present invention, the resistance value of the anchor layer may be equal to or greater than the resistance value of the sensing glass body.

In the liquid mass measurement device according to the second or third aspect of the present invention, the sensing glass body may have hydrogen ion sensitivity.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the glass electrode and the liquid quality measuring apparatus of the aspect of the present invention, it is possible to provide a glass electrode and a liquid quality measuring apparatus which are not easily broken, are easy to handle, have high production efficiency, and can achieve cost reduction.

Drawings

Fig. 1 is an external perspective view for explaining a pH meter 51 of example 1 as a liquid quality measuring apparatus according to an embodiment of the present invention.

Fig. 2 is a partial sectional view for explaining a table portion 1b in the pH meter 51.

Fig. 3 is a partial cross-sectional view for explaining a method for manufacturing a glass electrode 2 of example 1, which is a glass electrode according to an embodiment of the present invention, (a) is a view for explaining a process of applying a glass paste 2c, (b) is a view for explaining a process of placing a glass film portion 2a, and (c) is a view for explaining a state after firing of the glass paste 2 c.

Fig. 4 is a diagram illustrating the overall configuration of a pH meter 51A in example 2 of a liquid quality measurement device according to an embodiment of the present invention.

Fig. 5 is a partial sectional view for explaining the electrode portion 31 provided in the pH meter 51A.

Fig. 6 is a block diagram for explaining a measurement system of the pH meters 51 and 51A.

Fig. 7 is a first diagram for explaining a method of obtaining the correction value Mh in the pH meter 51.

Fig. 8 is a second diagram for explaining a method of obtaining the correction value Mh in the pH meter 51.

Detailed Description

The liquid quality measuring apparatus according to the embodiment of the present invention will be described with reference to the pH meter 51 of example 1 and the pH meter 52 of example 2. The pH meters 51 and 52 are devices for measuring pH indicating the hydrogen ion concentration of the liquid to be detected, as an example of a liquid quality measuring device for measuring the cation concentration of the liquid to be detected.

(example 1)

In fig. 1, the pH meter 51 is a hand-held type having a housing 1 that can be held with one hand. For convenience of explanation, the directions of the upper, lower, left, right, front, and rear are defined as the directions of arrows shown in fig. 1.

The housing 1 includes a main body 1a formed in a substantially rectangular parallelepiped shape that is thin in the vertical direction, and a base 1b that is seen in a front portion of the main body 1a so as to protrude in an upward annular shape.

A display unit 1a1 for displaying measurement results, operation modes, and the like, and an operation unit 1a2 formed of buttons and the like operated by a user are provided on the upper surface of the main body 1 a.

The table portion 1b has a receiving portion 1c for the liquid to be detected on the inner side. The liquid receiving portion 1c is a concave portion of a substantially truncated cone shape that is smoothly connected to the upper end surface of the table portion 1b with the axis line CLa extending in the vertical direction as the center and that has a diameter decreasing downward. The bottom of the liquid receiving unit 1c is a circular planar bottom surface 1c1 perpendicular to the axis CLa.

A circular glass film portion 2a provided at an end of the glass electrode 2 and an oblong end face of the liquid contact unit 3 are disposed so as to be exposed at the bottom surface portion 1c 1.

The glass film portion 2a is, for example, a flat inductive glass body having a diameter of 10mm and a thickness of 0.5 mm. The outer shape and thickness are not limited, and therefore, in the following description, the glass film portion will be referred to for convenience.

The glass membrane portion 2a is a flat plate-shaped member having ion sensitivity, and is formed of a known composition capable of obtaining hydrogen ion sensitivity, for use as the glass electrode 2 mounted on the pH meter 51.

The center of the glass film portion 2a is located slightly rearward of the axis line CLa, and the liquid contact unit 3 has an oblong shape elongated in the left-right direction and is located forward with respect to the glass film portion 2 a.

The upper surface 2a1 of the glass film portion 2a and the upper surface 3a of the liquid contact unit 3 form a surface having the same height without any step with respect to the bottom surface portion 1c 1.

An end face of a rod-shaped liquid-contacting portion 3b made of porous ceramic is exposed at the center of the upper surface 3a of the liquid-contacting unit 3.

Fig. 2 is a diagram for explaining the internal structure of the table portion 1b, and is a cross-sectional view perpendicular to the left-right direction at a position II-II in fig. 1.

As shown in fig. 1 and 2, the table portion 1b includes: an annular platform frame part 1b1 protruding upward from the upper surface of the main body part 1a of the housing 1; and a bottomed cylindrical electrode case 5 attached to the lower side of the base frame portion 1b1 inside the casing 1 and integrally formed with the base frame portion 1b 1.

The electrode case 5 has a cylindrical peripheral wall portion 5a and a top wall portion 5b provided above the peripheral wall portion 5a, and is formed in a bottomed cylindrical shape with a lower side open. The substantially lower half and the bottom face 1c1 of the liquid-to-be-detected containing section 1c are planar and form part of the top wall 5b of the electrode case 5.

A bottom cover 7 is attached to the lower end side inside the electrode case 5.

The bottom cover 7 is fixed to a lower portion of the inner surface of the peripheral wall 5a in a watertight state in which the gap is sealed by the O-ring 6 b.

The bottom cover 7 supports the rod-shaped reference electrode 8 in a vertically extending posture via the sealing member 7 b.

The electrode case 5 supports the columnar glass electrode 2 and the liquid contact unit 3 in a posture with the vertical direction as the axis.

Specifically, the glass electrode 2 is supported on both sides by the top wall portion 5b and the bottom cover 7, and the liquid contact unit 3 is supported on one side by the top wall portion 5 b.

The glass electrode 2 is attached to the top wall 5b and the bottom cover 7 in a watertight manner by sealing the gap with an O-ring 6a for the attachment hole 5b1 formed in the top wall 5b and sealing the gap with an O-ring 6c for the attachment hole 7a formed in the bottom cover 7.

Thus, an internal liquid containing chamber Vb of the reference electrode 8 is formed inside the electrode case 5, and the internal liquid containing chamber Vb is a space surrounded by the peripheral wall portion 5a, the top wall portion 5b, and the bottom cover 7, except for the glass electrode 2 and the liquid contact unit 3. The reference electrode 8 is disposed in the internal liquid receiving chamber Vb of the reference electrode 8.

Next, the glass electrode 2 and the liquid contact unit 3 will be described in detail.

(glass electrode 2)

The glass electrode 2 is formed in a cylindrical shape. Specifically, the glass electrode 2 includes: a base body 2b as a glass tube, a glass film portion 2a as an inductor attached to close one end face (upper face in fig. 2) of the base body 2b by a fixing layer 2c2, and a sealing portion 2e sealing the other end side (lower side) of the base body 2 b. The glass electrode 2 has a rod-shaped inner electrode 2d, and the inner electrode 2d is supported by the sealing portion 2e so as to face the glass film portion 2a while extending in the vertical direction.

The glass electrode 2 has an internal liquid storage chamber Va of the glass electrode 2, which is a space surrounded by the glass film portion 2a, the anchor layer 2c2, the base 2b, and the sealing portion 2 e.

The internal liquid storage chamber Va of the glass electrode 2 is filled with the internal liquid S1 (e.g., saturated KCl) of the glass electrode 2, and the tip of the inner electrode 2d is in the internal liquid S1 of the glass electrode 2.

The cable 2d1 is drawn from the inner pole 2d, and the other end of the cable 2d1 is connected to the circuit board 11 housed in the main body portion 1 a.

A method for manufacturing the glass electrode 2 will be described with reference to fig. 3.

In manufacturing the glass electrode 2, the glass film portion 2a and the base 2b are prepared.

First, as a material of the glass film portion 2a, a glass round rod having a predetermined diameter, which is a material of a hydrogen ion sensitive film and has a known composition, is produced.

Then, the glass round bar is sliced into a predetermined thickness and subjected to surface polishing as necessary to obtain a thin disk-shaped glass film portion 2a [ fig. 3(b) ].

On the other hand, the base body 2b is obtained by cutting a glass tube of a predetermined diameter and wall thickness into a predetermined length.

After the glass film portion 2a and the base 2b are prepared, as shown in fig. 3(a), the glass paste 2c is applied to one end face 2b1 of the base 2b by a dispenser 21 or the like. Here, the glass paste 2c before firing, which is so soft that it can be applied by the dispenser 21, is referred to as glass paste 2c 1.

Next, as shown in fig. 3(b), the glass film portion 2a is placed on the applied glass paste 2c1 and pressed with a predetermined force. Thereby, the glass paste 2c1 is sandwiched between the glass film portion 2a and the base 2b so as to be in close contact therewith. At this time, the end face 2b1 of the base 2b and the upper surface 2a1 of the glass film portion 2a are parallel to each other without being inclined.

Next, the substrate 2b and the glass film portion 2a adhered to the substrate 2b with the glass paste 2c1 interposed therebetween by the adhesiveness of the glass paste 2c1 are fired by using a firing profile (profile) formed by a predetermined temperature change and a predetermined time change. As a result, as shown in fig. 3(c), the glass paste 2c1 becomes a baked anchoring layer 2c 2.

The glass paste 2c1 is a so-called low-temperature firing type (firing temperature is, for example, 500 ℃ or lower), and the resistance value R2c2 after firing is equal to or higher than the resistance value Ra of the glass film portion 2 a.

Since the glass paste 2c is of a low-temperature firing type, the substrate 2b and the glass film portion 2a are sealed and integrated by the anchor layer 2c2 without undergoing alteration or the like.

The substrate 2b with the glass film portion 2a attached thereto is set in the vertical posture with the glass film portion 2a down, the internal liquid S1 of the glass electrode 2 is injected into the substrate 2b, the internal electrode 2d is immersed in the internal liquid S1, and the internal liquid S1 of the glass electrode 2 is sealed in a filled state by the sealing portion 2 e.

The glass electrode 2 was obtained by the above-described manufacturing method.

(liquid connecting unit 3)

The liquid contact unit 3 has a base body 3c formed in an elongated bottomed tubular shape with the bottom wall 3e as a bottom, a thin rod-shaped liquid contact portion 3b supported by the bottom wall 3e, and absorbent cotton 3d accommodated in an internal space Vc of the base body 3 c.

The liquid contact unit 3 is attached to the top wall portion 5b of the electrode case 5 with the bottom wall 3e upward.

The lower end side of the base body 3c is open to the inside of the internal liquid holding chamber Vb of the reference electrode 8, and the inside of the base body 3c is filled with the internal liquid S2 filled in the internal liquid holding chamber Vb of the reference electrode 8.

The liquid-contacting portion 3b is formed of a porous ceramic. The liquid-contacting portion 3b maintains the electrical connection between the liquid to be detected S3 stored in the storage portion 1c of the liquid to be detected in the table portion 1b and the internal liquid S2 of the reference electrode 8 filling the internal space Vc.

Here, the liquid connecting portion 3b and the absorbent cotton 3d may be porous resin or the like as long as the internal liquid S2 in the internal liquid storage chamber Vb of the reference electrode 8 can be guided to the internal space Vc and the liquid S3 to be detected.

The cable 8a connected to the reference electrode 8 is drawn out to the outside in a watertight state at the bottom cover 7 by the sealing member 7b, and is connected to the circuit substrate 11.

The circuit board 11 includes an arithmetic unit 12, and the arithmetic unit 12 calculates the pH value by a known method based on the potential difference between the electrically connected inner electrode 2d and the reference electrode 8.

In the above configuration, an openable and closable internal liquid injection port (not shown) is provided in the internal liquid storage chamber Vb of the reference electrode 8, and when the pH meter 51 is used, the internal liquid S2 (for example, saturated KCl) in which the reference electrode 8 is stored is filled. The injection (replenishment) of the internal liquid S2 of the reference electrode 8 may be performed by attaching and detaching the substrate 3c of the liquid junction cell 3 to and from the upper side.

The pH meter 51 described in detail above is placed on a table or the like so that the table portion 1b faces upward, and measures the pH of the liquid S3 to be detected.

Specifically, the measurement steps and the like will be described.

The liquid to be detected S3 whose pH is to be measured is added dropwise to the liquid to be detected storage section 1c of the table section 1b so that the glass film section 2a and the liquid-contacting section 3b are covered with one liquid block of the liquid to be detected S3.

The computing unit 12 of the circuit board 11 obtains the pH of the liquid S3 by a known pH computing method based on the potential difference between the internal electrode 2d and the reference electrode 8 caused by the immersion of the glass film portion 2a and the liquid-contacting portion 3b in the liquid S3.

Then, the obtained pH value is displayed on the display portion 1a 1.

The pH value may be corrected by the processing of the calculation unit 12. The process including this correction will be described in detail after the description of example 2.

The pH meter 51 as the liquid quality measuring apparatus is provided so that the upper surface 2a1 of the glass film portion 2a and the bottom surface 1c1 of the table portion 1b are flush with each other without any step. This facilitates cleaning after measurement, and the liquid S3 to be detected is almost completely removed by the cleaning without remaining.

Therefore, in the next measurement of a different liquid to be detected, the influence of the residual component of the liquid to be detected that has already been measured does not occur, and each measurement can be performed with high accuracy.

In the liquid quality measurement, the remaining of the liquid to be detected as a measured sample affects the measurement accuracy. Further, the remaining of a liquid such as water used for washing may affect the measurement result. Therefore, the portion containing the liquid to be detected must be cleaned reliably to avoid remaining.

In this respect, since the pH meter 51 has no step in the bottom surface portion 1c1, it is possible to reliably and easily perform cleaning by wiping off the liquid to be detected, the residual liquid, and the like in the storage portion 1c of the liquid to be detected including the bottom surface portion 1c1 with cloth or the like.

Since the glass film portion 2a is flat and sealed with the anchor layer 2c2 so as to be parallel to the end face 2b1 of the base 2b, it is less likely to be damaged than a thin hemispherical or partially spherical glass film protruding from the base in a conventional glass electrode.

The liquid storage section 1c is a concave section recessed in a substantially truncated cone shape, and its bottom surface section 1c1 is a flat electrode exposed surface. Therefore, the rod-shaped electrode does not need to be immersed in the liquid to be detected, and measurement can be performed even in a small amount of the liquid to be detected.

Thus, the pH meter 51 provided with the glass electrode 2 can be easily handled.

The glass film portion 2a can be obtained by mechanical slicing without manual work. That is, the thickness and shape of the glass film portion 2a can be highly uniformized, and mass production is possible.

Therefore, the pH meter 51 has a high production efficiency and can be manufactured at a low cost.

The glass electrode 2 is formed by fixing the glass film portion 2a to the base 2b with a glass paste 2c that can be fired at a temperature lower than the softening temperature of the glass film portion 2a and the base 2b, instead of welding the glass film portion 2a to itself.

Therefore, the glass film portion 2a can exhibit favorable physicochemical properties imparted to the glass film portion 2a without being affected by the firing of the glass paste on both surfaces thereof.

Further, the outer peripheral surface of the portion of the glass electrode 2 above the O-ring 6a sealing the space between the glass electrode 2 and the mounting hole 5b1 is in contact with the liquid S3 to be detected.

Specifically, the portion of the base 2b above the portion in contact with the O-ring 6a, the anchor layer 2c2 obtained by firing the glass paste 2c, and the glass film portion 2a are in contact with the liquid S3 to be detected.

Therefore, in order to prevent the resistance value R2c2 of the anchor layer 2c2 from affecting the measurement potential of the inner electrode 2d and lowering the measurement accuracy of the pH value, it is desirable that the resistance value R2c2 of the anchor layer 2c2 is equal to or greater than the resistance value Ra of the glass film portion 2 a.

(example 2)

The pH meter 51A of example 2 will be described with reference to fig. 4 and 5. Fig. 4 is a diagram for explaining the entire configuration of the pH meter 51A, and fig. 5 is a partial sectional view for explaining the configuration of the electrode portion 31 provided in the pH meter 51A.

The pH meter 51A includes a rod-shaped electrode portion 31 and a measurement body portion 34 connected to the electrode portion 31 via an electric wire 33.

The measurement main body portion 34 includes a display portion 1Aa1 for displaying measurement results, operation modes, and the like on the outer surface thereof, and an operation portion 1Aa2 formed by buttons or the like operated by a user, and includes an arithmetic portion 12A therein.

As shown in fig. 5, the electrode portion 31 includes an elongated cylindrical glass electrode 35 and an annular cylindrical portion 36 of an internal liquid storage chamber VAb having an annular reference electrode 37 formed outside the glass electrode 35. Fig. 5 shows a posture in which the electrode portion 31 stands in the vertical direction, and this posture is also a posture of the electrode portion 31 at the time of measurement.

The glass electrode 35 is formed by the same method and with the same structure as the glass electrode 2.

That is, the glass electrode 35 has: a base body 35b as a glass tube; a glass film portion 35a as a flat induction glass body attached so as to close one end surface (lower surface in fig. 5) of the base body 35 b; and a sealing portion 35e that seals the other end side (upper side in fig. 5) of the base body 35 b. The glass electrode 35 has a rod-shaped inner pole 35d, and the inner pole 35d is supported by the sealing portion 35e so as to face the glass film portion 35a while extending in the vertical direction.

The glass film portion 35a is sealed and integrated with the end face 35b1 of the base 35b via the anchor layer 35c obtained by firing the glass paste 2 c.

The glass electrode 35 has an internal liquid containing chamber VAa of the glass electrode 2, and the internal liquid containing chamber VAa is a space surrounded by the glass film portion 35a, the anchor layer 35c, the base 35b, and the sealing portion 35 e.

The internal liquid storage chamber VAa of the glass electrode 35 is filled with the internal liquid S1 (e.g., saturated KCl) of the glass electrode 35, and the tip of the inner electrode 35d is positioned in the internal liquid S1 of the glass electrode 35.

The cable 35d1 is drawn from the rear end of the inner pole 35d, and the other end of the cable 35d1 is connected to the arithmetic unit 12A (see fig. 4 and 6) of the circuit board (not shown) housed in the measurement main body unit 34.

The lower surface 36a of the annular cylindrical portion 36 is positioned above the glass film portion 35a of the glass electrode 35, and the annular cylindrical portion 36 is integrated with the glass electrode 35 in a stepped manner in which the glass electrode 35 protrudes from the lower surface 36 a.

The annular cylindrical portion 36 has an inner liquid accommodating chamber VAb of an annular reference electrode 37 formed radially outside the glass electrode 35.

A thin rod-shaped liquid-contacting portion 36b is attached to the annular cylindrical portion 36, and the liquid-contacting portion 36b is exposed on the lower surface 36a of the annular cylindrical portion 36 and extends in the vertical direction in the internal liquid-containing chamber VAb of the reference electrode 37. The liquid-contacting portion 36b is formed of, for example, porous ceramic.

In the internal liquid storage chamber VAb of the reference electrode 37, absorbent cotton 36d is stored above the liquid-contacting portion 36 b.

The upper end of the internal liquid accommodation chamber VAb of the reference electrode 37 is sealed by an annular sealing portion 36 e.

A rod-shaped reference electrode 37 is attached to the inside of the internal liquid containing chamber VAb of the reference electrode 37 in a posture extending in the vertical direction.

The internal liquid storage chamber VAb of the reference electrode 37 sealed by the sealing portion 36e is filled with the internal liquid S2 (e.g., KCL) of the reference electrode 37. Therefore, the reference electrode 37 is in a state of being immersed in the internal liquid S2 of the reference electrode 37.

A cable 37a is led upward from the reference electrode 37.

The cable 37a and the cable 35d1 from the inner pole 35d are gathered together and connected to the measurement main body portion 34 as an electric wire 33 (fig. 4) extending from the electrode portion 31.

As shown in fig. 4, the pH meter 51A measures pH by immersing the electrode portion 31 in the liquid S3 so that at least the liquid contacting portion 36b and the glass film portion 35a are immersed in the liquid S3, and the liquid S3 is put in the container 22 for the liquid S3 such as a beaker.

At this time, the liquid connecting portion 36b maintains the electric connection between the liquid S3 to be detected and the internal liquid S2 of the reference electrode 37 in the internal liquid storage chamber VAb filled with the reference electrode 37.

(correction of measurement value)

Next, the correction of the measurement values in the pH meter 51 of example 1 and the pH meter 51A of example 2 will be described.

Fig. 6 is a block diagram illustrating a measurement system of the pH meters 51 and 51A. The reference numerals corresponding to the pH meter 51A are shown in parentheses, and the measurement system is the same as the pH meter 51. In the following description, the pH meter 51 will be described as a representative.

The calculation unit 12 includes: a measuring section 12a for determining the potential difference between the internal electrode 2d and the reference electrode 8; and a determination unit 12b for calculating the pH value by a known calculation method based on the potential difference or the like obtained by the measurement unit 12 a.

The calculation unit 12 further includes: a correction unit 12c for obtaining a corrected pH value based on a correction amount Δ pH, which is measured in advance and will be described later; and a storage unit 12d for storing the correction amount Δ pH and the like.

The determination unit 12b also controls the operation of the entire pH meter 51.

The instruction input from the operation unit 1a2 by the user or the like is transmitted to the determination unit 12b and the operation is executed. The operating state and the obtained pH are output from the determination unit 12b to the display unit 1a 1.

The correction amount Δ pH is a value for correcting the individual difference in the inductance of the glass electrode 2.

The sensitivity of the glass film portion 2a and the resistance value of the anchor layer 2c2 may vary slightly among the glass electrodes 2.

By correcting the individual difference, the pH meter 51 can favorably suppress the measurement variation for each product, and can maintain high quality.

The correction amount Δ pH is obtained, for example, by the following method.

First, the resistance value Ra corresponding to the resistance value between the inner and outer surfaces of the single glass film portion 2a is obtained by the method shown in fig. 7.

Specifically, the glass electrode 2 is set in a posture in which the glass film portion 2a is located upward, the O-ring 24 having substantially the same diameter as the base 2b is placed on the glass film portion 2a, and water S4 is accumulated inside the O-ring 24.

In this state, the electrode 23 was immersed in water S4, and the resistance value between the electrode 23 and the inner electrode 2d (between P1 and P2) was measured and used as the resistance value Ra. This value is, for example, about 850(M Ω).

Next, as shown in fig. 8, the resistance value R2c2 of the anchor layer 2c2 was determined, and the resistance value R2c2 was substantially the resistance value between the liquid S3 to be detected and the internal liquid S2 of the reference electrode 37.

Specifically, in a state where the pH of the liquid to be detected S3 is measured as the pH meter 51, the resistance value between the electrode 23 and the inner electrode 2d (between P3 and P2) immersed in the liquid to be detected S3 is measured, and the resistance value is defined as the combined resistance value R. At this time, the combined resistance value R is represented by 1/R ═ 1/Ra) + (1/R2c2 from the resistance value Ra of the single glass film portion 2a and the resistance value R2c2 of the anchor layer 2c 2.

The base body 2b in contact with the liquid S3 to be detected and the internal liquid S2 of the reference electrode 37 can be substantially regarded as an insulator in the case of a glass tube. In contrast, when the anchor layer 2c2 is formed by firing the glass paste 2c adjusted to have a viscosity that can be applied at room temperature, a leakage current may flow through the anchor layer 2c2 having an outer peripheral surface in contact with the liquid S3 to be detected and an inner peripheral surface in contact with the internal liquid S2 of the reference electrode 37. That is, the combined resistance value R may be smaller than the resistance value Ra. Here, the combined resistance value R is, for example, about 700(M Ω).

As described above, the resistance value R2c2 is calculated from the measured resistance value Ra and the combined resistance value R.

The relationship between the obtained resistance value R2c2 and the correction amount Δ pH for each pH value of the resistance value R2c2, which is grasped by measurement using a standard sample solution having a predetermined pH value, is determined in advance. This relationship is stored in the storage unit 12d in advance, for example, as a correction table Tm.

Further, in the manufacturing stage of the pH meter 51, the resistance values R2c2 of the anchor layers of the respective individuals measured by the above-described method are stored in the storage portion 12d in advance.

The pH meter 51 performs the following correction processing when measuring the pH of the liquid to be detected S3.

The determination unit 12b determines the pH Q by a known pH calculation method based on the potential difference from the measurement unit 12 a.

The determination unit 12b supplies the obtained pH value Q to the correction unit 12 c.

The correction unit 12c refers to the correction table Tm stored in the storage unit 12d, reads the correction amount Δ pHq corresponding to the supplied pH value Q when the resistance value of the anchor layer 2c2 is the resistance value R2c2, and transmits the correction amount Δ pHq to the determination unit 12 b.

The determination unit 12b adds the correction amount Δ pHq transmitted from the correction unit 12c to the determined pH value Q, determines the obtained value as a corrected pH value, and displays the corrected pH value on the display unit 1a 1.

The correction processing will be specifically described.

For example, when the resistance value R2c2 of the anchor layer 2c2 of the pH meter 51 is 4000(M Ω) and the pH value Q before correction obtained by the determination unit 12b is 6.35, the correction unit 12c reads the correction amount Δ pHq when the pH value Q is 6.3 with reference to the correction amount column for each pH value when the resistance value R2c2 of the correction table Tm is 4000(M Ω).

When the correction amount Δ pHq is 0.01, the determination unit 12b determines and outputs 6.36 obtained by adding 0.01 to 6.35 of the pH value Q as the corrected pH value.

When the use time of the pH meter 51 reaches a predetermined time, the correction table Tm stored in the storage unit 12d may be updated (rewritten) by measuring again the resistance value R2c2 of the anchor layer 2c2 with a standard test solution as maintenance.

The pH meter 51(51A) has a glass electrode 2(35) in which a thin disk-shaped glass film portion 2a (35a) is fixed to a base 2b (35b) by an anchor layer 2c2(35 c). Further, since the correction unit 12c is provided to correct the individual difference of the measurement system having the above configuration when the individual difference occurs, it is possible to perform measurement with high accuracy.

Whether or not to correct the pH value Q is desirably determined based on the display resolution of the pH meter 51(51A) and the combined resistance value difference Δ R.

The embodiment of the present invention is not limited to the configuration and procedure of example 1 (example 2), and may be modified within a range not departing from the gist of the present invention.

The dispenser 21 is used as a method of applying the glass paste 2c to the base 2b (35b) of the glass electrode 2(35), but the application may be performed by another method such as screen printing.

The example of using a low-temperature-firing glass paste has been described as the anchor layer 2c2(35c) for sealing the substrate 2b (35b) and the glass film portion 2a (35a), but a low-temperature-firing glass ingot (tablet) or the like may be used. In this case, the glass frit (frit) of the low melting point glass is pressed in advance into an annular shape corresponding to the shape of the end face 2b1(35b1) of the base 2b (35b), placed on the end face 2b1(35b1), and the glass film portion 2a (35a) is placed thereon and fired.

The O-rings 6a to 6c are not limited to O-rings as long as they can maintain a watertight state.

Although the substrate 2b (35b) is described as the insulator in the description of example 1 (example 2), the substrate 2b (35b) may be capable of flowing a current slightly like the anchor layer 2c2(35 c).

In this case, the determination unit 12b determines the pH value by performing the correction based on the correction amount Δ pH of the pH value supplied from the correction unit 12c, and thereby the influence of the base 2b (35b) can be eliminated and the pH value can be obtained with high accuracy.

In practice, since the substrate 2b (35b) is a glass tube and can be regarded as an insulator, it is desirable that the resistance value R2c2 of the baked anchor layer 2c2(35c) is equal to or greater than the resistance value Ra of the glass film portion 2a (35a) with respect to the glass paste 2c as described above.

The anchor layer 2c2(35c) has a smaller contact area with the liquid S3 to be detected and the internal liquid S2 of the reference electrode 37 than the glass film 2a, and therefore the correction amount Δ pH is very small.

Depending on the accuracy required of the pH meter 51(51A), the calibration itself may not be necessary.

The determination unit 12a may output the measurement value not only by display on the display unit 1a1(1Aa1), but also by wire or wirelessly as data.

As described above, the present invention naturally includes various embodiments and the like not described herein. Therefore, the technical scope of the present invention is determined only by the specific matters of the invention according to the claims that are appropriate from the above description.

The entire contents of Japanese patent application laid-open No. 2017-115124 (application date: 6/12/2017) are incorporated herein by reference.

Industrial applicability

According to the glass electrode and the liquid quality measuring apparatus according to the embodiments of the present invention, it is possible to provide a glass electrode and a liquid quality measuring apparatus which are not easily broken and easily handled, and which have high production efficiency and can achieve cost reduction.

Description of the reference numerals

1: frame, 1 a: body portion, 1a1, 1Aa 1: display unit, 1a2, 1Aa 2: operation unit, 1 b: table portion, 1b 1: frame portion, 1 c: detected liquid storage unit, 1c 1: bottom surface portion, 2: glass electrode, 2 a: glass film portion (sensing glass body), 2a 1: upper surface, 2 b: substrate, 2b 1: end face, 2c (2c 1): glass paste, 2c 2: anchor layer, 2 d: inner pole, 2d 1: cable, 2 e: sealing portion, 3: liquid connection unit, 3 a: upper surface, 3 b: liquid-contacting portion, 3 c: base, 3 d: absorbent cotton, 3 e: bottom wall, 5: electrode casing, 5 a: peripheral wall portion, 5 b: top wall portion, 5b 1: mounting hole, 6a, 6b, 6 c: o-ring, 7: bottom cover, 7 a: mounting hole, 7 b: sealing member, 8: reference electrode, 8 a: cable, 11: circuit board, 12A: calculation unit, 12 a: measurement unit, 12 b: determination section, 12 c: correction unit, 12 d: storage unit, 21: dispenser, 22: detected liquid container, 23: electrode, 24: o-ring, 31: electrode portion, 33: electric wire, 34: measurement body, 35: glass electrode, 35 a: glass film portion (sensing glass body), 35 b: substrate, 35b 1: end face, 35 c: anchor layer, 35 e: seal portion, 35 d: inner pole, 35d 1: cable, 36: annular cylinder portion, 36 a: lower surface, 36 b: liquid-joining portion, 36 d: absorbent cotton, 36 e: seal portion, 37: reference electrode, 37 a: cable, 51A: pH meter (liquid quality measuring device), CLa: axis, Q: pH value, R: combined resistance value, Ra, Rb, R2c 2: resistance value, S1: glass electrode internal liquid, S2: reference electrode internal liquid, S3: detected liquid, S4: water, Tm: calibration tables, Va, VAa glass electrode internal liquid storage chambers, Vb, VAb: reference electrode internal liquid storage chamber, Vc: internal space, Δ R: resulting in a difference in resistance values.