JP2009257854A - Electrochemical sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochemical sensor capable of acquiring the extent of the consumption of a reagent. <P>SOLUTION: An electrochemical sensor causes an electrochemical reaction to be developed between an electrode 4 and an electrode 5 arranged in a reagent, measures a physical quantity of a measuring liquid 1 by detecting a current I generated between the electrodes, and consumes a reagent 3 in the measurement. The electrochemical sensor includes a consumption calculation part 11 which obtains an integrated value of the current I and calculates the consumption amount of the reagent 3 on the basis of the integrated value. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrochemical sensor, and more specifically, an electrochemical reaction is caused between electrodes arranged in a measurement object or a reagent, and a physical quantity of the measurement object is measured by detecting a current or voltage generated between the electrodes. In addition, the present invention relates to an electrochemical sensor that consumes a reagent during measurement.

  FIG. 5 is a view showing a diaphragm type galvanic cell dissolved oxygen meter as an example of a conventional electrochemical sensor. The dissolved oxygen meter is a measuring device that measures the amount of oxygen dissolved in water (dissolved oxygen amount DO).

  The measurement liquid 1 is accommodated in the container A. The reagent 3 is accommodated in the container B. A diaphragm 2 is formed on the bottom wall of the container B. The lower part of the container B is in contact with the measurement liquid 1. The dissolved oxygen meter includes a diaphragm 2, a reagent 3 isolated from the measurement liquid 1 through the diaphragm 2, an indicator electrode 4 and a counter electrode 5 disposed in the reagent 3, and a cable 61 connected to the indicator electrode 4. The cable 62 connected to the counter electrode 5, the temperature sensor 7 for measuring the temperature of the diaphragm 2, and the other ends of the cables 61 and 62 are connected to measure the current flowing between the indicator electrode 4 and the counter electrode 5. And an oxygen concentration calculation unit 9 that calculates the dissolved oxygen amount DO in the measurement liquid 1 based on the current, and a display unit 10 that displays the calculated dissolved oxygen amount DO.

  The diaphragm 2 is a Teflon (registered trademark) (registered trademark) membrane having high permeability to oxygen. The indicator electrode 4 is a silver electrode, and the counter electrode 5 is a lead electrode. The indicator electrode 4 is disposed close to the diaphragm 2. The counter electrode 5 is disposed at a position away from the diaphragm 2 and the indicator electrode 4. Reagent 3 is an electrolytic solution of potassium hydroxide (KOH).

The measurement of the dissolved oxygen amount DO of the measurement liquid 1 is performed by decomposing oxygen in the measurement liquid 1 by an oxidation-reduction reaction and measuring an oxidation-reduction current generated at that time.
When oxygen in the measurement liquid 1 reaches the diaphragm 2, the following electrochemical reaction occurs at the indicator electrode 4 and the counter electrode 5.
Counter electrode 5: 2Pb + 4 (OH) - + 2KOH → 2K + + 2HPbO 2 - + 2H 2 O + 4e - ( Equation 1)
Indicator electrode 4: O ₂ + 2H ₂ O + 4e ⁻ → 4 (OH) ⁻ (Formula 2)

  That is, oxygen that has reached the diaphragm 2 is decomposed at the indicator electrode 4, and the oxidation-reduction current I flows through the cables 61 and 62. The redox current I is proportional to the amount of decomposed oxygen. The redox current I is proportional to the amount of oxygen that has permeated through the diaphragm 2. Therefore, by measuring the oxidation-reduction current I, the dissolved oxygen amount DO of the measurement liquid 1 can be obtained. The oxygen concentration calculation unit 9 receives the measurement value of the ammeter 8 and calculates the dissolved oxygen amount DO based on the oxidation-reduction current I. Note that the oxygen permeability of the Teflon (registered trademark) film varies depending on the temperature. The temperature of the diaphragm 2 is measured by the temperature sensor 7, and the value of the dissolved oxygen amount DO is corrected. The obtained dissolved oxygen amount DO is displayed on the display unit 10.

  As can be seen from the above formulas 1 and 2, two potassium hydroxide molecules are consumed at the counter electrode 5 when one oxygen molecule is decomposed at the indicator electrode 4. Therefore, when the amount of dissolved oxygen DO is measured, potassium hydroxide molecules contained in the reagent 3 are consumed by the electrochemical reaction and reduced. When all the potassium hydroxide in the reagent 3 is consumed, the dissolved oxygen amount DO cannot be measured. Therefore, the reagent 3 needs to be periodically replaced or filled. Patent Document 1 below discloses a dissolved oxygen meter having a reagent reservoir.

JP-A-60-125556

  However, the conventional dissolved oxygen meter does not have an index indicating the degree of consumption of the reagent 3. For this reason, there is a problem that the reagent 3 that can still be used is replaced at the time of periodic replacement, and the purchase cost and replacement time of the reagent 3 are wasted. On the other hand, when the reagent 3 is completely consumed before the regular replacement, there is a problem that a period during which normal measurement cannot be performed occurs.

  It is an object of the present invention to realize an electrochemical sensor that can eliminate the problems of the prior art and grasp the degree of reagent consumption.

In order to achieve the above object, the invention of claim 1
Electrochemical reaction between the electrodes placed in the measurement target or reagent, and the physical quantity of the measurement target is measured by detecting the current or voltage generated between the electrodes, and the reagent consumes the reagent during the measurement. In the sensor
It is characterized in that a consumption amount calculation unit for obtaining an integrated value of current or voltage and calculating a consumption amount or a residual amount of the reagent based on the integration value is provided.

The invention of claim 2
A diaphragm that separates the measurement target from the reagent;
An indicator electrode disposed in the reagent and disposed in proximity to the diaphragm;
A counter electrode disposed via a reagent between the indicator electrode and
An ammeter that detects the current flowing between the indicator electrode and the counter electrode;
In an electrochemical sensor for measuring a physical quantity to be measured,
The present invention is characterized in that a consumption amount calculation unit is provided which calculates an integrated value of the current value detected by the ammeter and calculates a consumption amount or a residual amount of the reagent based on the integration value.

The invention of claim 3
The electrochemical sensor according to claim 2, wherein the reagent, the diaphragm, the indicator electrode, and the cartridge container containing the counter electrode,
The cartridge container is provided with a detachable receptacle.

The invention of claim 4
4. The electrochemical sensor according to claim 1, wherein the consumption amount calculation unit outputs a signal indicating the consumption amount or remaining amount of the reagent.

The invention of claim 5
5. The electrochemical sensor according to claim 1, wherein the consumption amount calculation unit outputs a signal indicating the consumption of the reagent when the consumption amount of the reagent exceeds a predetermined value.

The invention of claim 6
The electrochemical sensor according to any one of claims 1 to 5, wherein a prediction for predicting a time when the reagent consumption exceeds a predetermined value is made based on an output of the consumption calculator and an elapsed time from the use start time of the reagent. It has the part.

The invention of claim 7
The electrochemical sensor according to claim 6, further comprising a display unit that displays at least one of a consumption amount or a residual amount of the reagent or a time when the consumption amount of the reagent exceeds a predetermined value.

The invention of claim 8
8. The electrochemical sensor according to claim 1, wherein the physical quantity to be measured is a dissolved oxygen quantity.

Thus, according to the invention of claim 1,
By providing a consumption calculation unit that calculates the current consumption or voltage between the electrodes placed in the measurement target or reagent and calculates the reagent consumption based on this integration value, the degree of reagent consumption can be reduced. An electrochemical sensor that can be grasped can be realized.

According to the invention of claim 2,
An electrochemical sensor that can determine the level of reagent consumption by providing a consumption calculation unit that calculates an integrated value of the current flowing between the indicator electrode and the counter electrode, and calculates the reagent consumption based on the integrated value. Can be realized.

According to the invention of claim 3,
Since the reagent, the diaphragm, the indicator electrode, and the counter electrode are formed into a cartridge, the cartridge can be replaced when the reagent is consumed.

According to the invention of claim 4,
Since the consumption amount calculation unit outputs a signal indicating the consumption amount or the remaining amount of the reagent, this signal can be used for communication. When used for communication, the electrochemical sensor user can grasp the level of reagent consumption while at a remote location.

According to the invention of claim 5,
Since the consumption amount calculation unit outputs a signal indicating the consumption of the reagent when the consumption amount of the reagent exceeds a predetermined value, this signal can be used for communication or an alarm alarm.

According to the invention of claim 6,
Since the prediction unit for predicting the time when the consumption amount of the reagent exceeds the predetermined value is provided, the user of the electrochemical sensor can know in advance the time when the reagent should be replaced or filled next time.

  According to the seventh aspect of the invention, since the display unit displays at least one of the consumption amount or the remaining amount of the reagent or the time when the consumption amount of the reagent exceeds a predetermined value, the user of the electrochemical sensor can use the reagent. It is possible to always grasp the degree of consumption and the next replacement date of the reagent.

According to the invention of claim 8,
A dissolved oxygen meter capable of grasping the degree of consumption of the reagent can be realized.

FIG. 1 is a diagram showing the configuration of an embodiment in which the present invention is applied to a dissolved oxygen meter. This example shows a diaphragm type galvanic cell type dissolved oxygen meter. In this embodiment, a consumption calculation unit 11, a prediction unit 12, and a display unit 13 are added to the dissolved oxygen meter of the conventional example shown in FIG.

  The measurement liquid 1 is accommodated in the container A. The reagent 3 is accommodated in the container B. A diaphragm 2 is formed on the bottom wall of the container B. The reagent 3 is isolated from the measurement liquid 1 through the diaphragm 2. The container B is held with respect to the container A by a support member C (not shown) so that the bottom wall of the container B is in contact with the measurement liquid 1.

  An indicator electrode 4 and a counter electrode 5 are disposed in the reagent 3. The indicator electrode 4 is attached to the lower end of a support member D (not shown) that extends from the upper outside to the vicinity of the bottom wall of the container B through the upper end opening of the container B. When the indicator electrode 4 is attached to the support member D, the position of the indicator electrode 4 is adjusted so that the end face of the tip thereof is close to the diaphragm 2. The counter electrode 5 is attached to a side surface of the support member D at a position away from the indicator electrode 4.

  The diaphragm 2 is a Teflon (registered trademark) film having high permeability to oxygen. The side wall of the container B is formed of SUS (stainless steel). The indicator electrode 4 is a silver electrode, and the counter electrode 5 is a lead electrode. Reagent 3 is an electrolytic solution of potassium hydroxide (KOH).

  Cables 61 and 62 are connected to the indicator electrode 4 and the counter electrode 5, respectively. An ammeter 8 is connected to the other ends of the cables 61 and 62. The temperature sensor 7 is a sensor that measures the temperature of the diaphragm 2. The temperature sensor 7 is attached to the lower end of the support member D, and the position is adjusted so as to be suitable for the temperature measurement of the diaphragm 2. The ammeter 8 measures a redox current I flowing between the indicator electrode 4 and the counter electrode 5. The oxygen concentration calculation unit 9 calculates the dissolved oxygen amount DO in the measurement liquid 1 based on the oxidation-reduction current I. The calculated dissolved oxygen amount DO is displayed on the display unit 10.

The relationship between the oxidation-reduction current I and the consumption amount of the reagent 3 will be described.
Counter electrode 5: 2Pb + 4 (OH) - + 2KOH → 2K + + 2HPbO 2 - + 2H 2 O + 4e - ( Equation 1)
Indicator electrode 4: O ₂ + 2H ₂ O + 4e ⁻ → 4 (OH) ⁻ (Formula 2)
The amount of oxygen molecules decomposed at the indicator electrode 4 is proportional to the amount of potassium hydroxide (KOH) molecules consumed at the counter electrode 5. The redox current I is proportional to the amount of decomposed oxygen. Therefore, the consumption amount of the reagent 3 is proportional to the redox current I.

From Formula 1 and Formula 2, two potassium hydroxide molecules are consumed by the movement of four electrons. That is, the consumption of one potassium hydroxide molecule corresponds to the movement of two electrons. The total amount Q of charges transferred from the indicator electrode 4 to the counter electrode 5 after the use of the reagent 3 is started is the time integration of the oxidation-reduction current I. The charge of one electron is 1.6 × 10 ^-19 [C]. Thus, the following calculation formula is established.

Since the consumption of one potassium hydroxide molecule corresponds to the movement of two electrons, the consumption amount (consumption number) of potassium hydroxide molecules is as follows.

When the redox current I is measured at a constant period T as shown in FIG. 2, Equation 4 can be expressed as follows.

The number of potassium hydroxide molecules contained in the reagent 3 can be calculated from the concentration and amount of the reagent 3. When the number of molecules at the start of use of the reagent 3 is N, the consumption rate of potassium hydroxide can be expressed as follows.

  FIG. 3 is a block diagram showing the oxygen concentration calculator 9 and the consumption calculator 10. FIG. 3A is a block diagram of the oxygen concentration calculator 9. FIG. 3B is a block diagram of the consumption calculation unit 10.

  The oxygen concentration calculation unit 9 includes a temperature calculation unit 9a and a calculation unit 9b. The temperature calculation unit 9 a receives the output of the temperature sensor 7 and converts it into the temperature of the diaphragm 2. The calculation unit 9 b receives the oxidation-reduction current I and calculates the dissolved oxygen amount DO in the measurement liquid 1. At this time, the value of the dissolved oxygen amount DO is corrected based on the temperature information of the diaphragm 2 obtained by the temperature calculation unit 9a.

の計算を行い、計算結果を計算部１１ｂに出力する。 The consumption calculation unit 11 includes an integration unit 11a, a calculation unit 11b, and a comparison unit 11c. The consumption calculation unit 11 receives the redox current I measured by the ammeter 8. The accumulating unit 11a collects the current value of the oxidation-reduction current I at a constant period T (for example, T = 60 s) and stores it as I ₁ , I ₂ , I ₃ . The accumulating unit 11a

And the calculation result is output to the calculation unit 11b.

  The calculation part 11b calculates Formula 6 using the calculation result of the integrating | accumulating part 11a, and calculates the consumption rate of potassium hydroxide. The calculated consumption rate of the reagent 3 is output to the comparison unit 11c, the prediction unit 12, and the display unit 13. A signal indicating the consumption rate of the reagent 3 is used as the signal S1 for external communication.

  The comparison unit 11c compares the consumption rate of the reagent 3 with a preset threshold (for example, 90%). The comparison unit 11c determines that the reagent 3 is consumed when the consumption ratio exceeds 90%, and outputs an alarm signal S2.

  The prediction unit 12 stores the use start time of the reagent 3. The prediction unit 12 uses the dissolved oxygen meter continuously at the current pace based on the consumption rate of potassium hydroxide input from the consumption calculation unit 11 and the elapsed time from the use start time of the reagent 3. The due date D when the consumption rate of the reagent 3 exceeds 90% is predicted. The due date D is output to the display unit 13. The oxygen concentration calculation unit 9, the consumption calculation unit 11, and the prediction unit 12 are constituted by a CPU and its peripheral circuits (memory, etc.).

  The display unit 13 displays the dissolved oxygen amount DO calculated by the oxygen concentration calculation unit 9. In addition, the consumption rate of potassium hydroxide input from the consumption calculation unit 11 is displayed as the consumption amount of the reagent 3. Further, the due date D input from the prediction unit 12 is displayed as the next reagent replacement date.

The present embodiment is configured as described above, and includes the consumption amount calculation unit 11 that calculates the consumption amount of the reagent 3 based on the current value I flowing between the indicator electrode 4 and the counter electrode 5. The level of consumption can be grasped. As a result, it is possible to avoid a situation in which the reagent 3 is exchanged even though it is still usable, or measurement is performed without noticing that all of the reagent 3 has been consumed.
Moreover, since the consumption amount of the reagent 3 is calculated using the current value of the ammeter 8 that is originally provided in order to obtain the dissolved oxygen amount DO, a new device is not required for the calculation. Since only the addition of the software corresponding to the consumption calculation unit 11 and the prediction unit 12 is required, it can be realized at low cost.

  Moreover, since the consumption calculating part 11 outputs the signal S1 which shows the consumption of the reagent 3, the user of the dissolved oxygen meter of a present Example is a reagent while using this signal S1 for communication, while being in a remote place. The degree of consumption of 3 can be grasped.

  Further, since the consumption amount calculation unit 11 outputs an alarm signal S2 indicating consumption of the reagent 3 when the consumption amount of the reagent 3 exceeds a predetermined value, it can be used for alarm warning and communication. As a result, the user of the dissolved oxygen meter of the present embodiment can be made aware of the consumption of the reagent 3 and can be prompted to replace the reagent 3.

  In addition, since the prediction unit 12 that predicts the time when the consumption amount of the reagent 3 exceeds a predetermined value is provided, the user of the dissolved oxygen meter of the present embodiment can know in advance when the reagent should be replaced or filled next time. it can.

  Further, since the display unit 13 for displaying the consumption amount and the due date D of the reagent 3 is provided, the user of the dissolved oxygen meter of the present embodiment can always grasp the consumption level of the reagent 3 and the next reagent replacement date. .

  In the present embodiment, the consumption amount of the reagent 3 is calculated by the consumption amount calculation unit 11, but the remaining amount of the reagent 3 may be calculated. Further, although the consumption amount of the reagent 3 is displayed on the display unit 13, the remaining amount may be displayed. In this embodiment, the temperature sensor 7 measures the temperature of the diaphragm 2. However, the temperature sensor 7 considers that the diaphragm 2, the reagent 3, and the indicator electrode 4 are in thermal equilibrium, and the temperature sensor 7 uses the reagent 3 and the indicator electrode 4. May be used as the temperature of the diaphragm 2. When substituting the temperature measurement of the indicator electrode 4, the temperature sensor 7 may be incorporated in the indicator electrode 4.

In the present embodiment, the period at which the consumption calculation unit 11 collects the current value of the oxidation-reduction current I is set to a constant period T = 60 s, but the period T is not limited to this. Depending on the frequency of use of the dissolved oxygen meter and the oxygen concentration of the measurement liquid 1, the period T may be set to another value. Further, the period T may not always be constant. For example, when the consumption rate of potassium hydroxide is 0% to 50%, the cycle T ₁ , 50% to 75% is the cycle T ₂ , and when 75% or more, the cycle T ₃ is used. It may be changed accordingly. Further, the shorter the period T, the more accurately the consumption rate of potassium hydroxide can be calculated.

  In this embodiment, it is determined that the reagent 3 is consumed when the consumption ratio of potassium hydroxide exceeds 90%. However, the threshold value may be set to another value. It is set to a value that is considered appropriate depending on the usage frequency of the dissolved oxygen meter, the oxygen concentration and temperature of the measurement liquid 1, the speed of the application in which the dissolved oxygen meter is used, and the like.

In this embodiment, the example in which the present invention is applied to a diaphragm type galvanic cell type dissolved oxygen meter has been described. However, the present invention can also be applied to a diaphragm type polarographic electrode type dissolved oxygen meter. In addition, the present invention measures the physical quantity of the measurement target by causing an electrochemical reaction between the electrodes and detecting the current generated between the electrodes, and uses other electricity as long as the reagent is consumed in the measurement. It can also be applied to chemical sensors. For example, it can be applied to an alkalinity meter, acidity meter, residual chlorine meter, and sodium meter.
In addition, in the case of an electrochemical sensor that causes an electrochemical reaction between electrodes and detects the voltage generated between the electrodes to measure the physical quantity to be measured, the consumption of the reagent can be achieved even if voltage is used instead of current. The amount can be calculated.
In addition, the indicator electrode 4 and the counter electrode 5 in a present Example are equivalent to the electrode of Claim 1. The measurement liquid 1 corresponds to the measurement object in claims 1 and 2.

  Next, Example 2 will be described. In this embodiment, the container B, the diaphragm 2, the reagent 3, the indicator electrode 4, the counter electrode 5, and the temperature sensor 7 are made into a cartridge as compared with the first embodiment.

  FIG. 4 is a diagram showing a cartridge-type dissolved oxygen meter as Example 2. As shown in FIG. B 'is a cartridge container. Reference numeral 15 denotes a connector portion provided in the cartridge container B '. The cartridge container B ′ is attached to and detached from the receptacle 16 by the connector portion 15. The cartridge container B 'is entirely formed of SUS, and a diaphragm 2 is formed on the bottom wall. The inside of the cartridge container B ′ is filled with the reagent 3. An indicator electrode 4, a counter electrode 5, and a temperature sensor 7 are disposed in the reagent 3.

  The cartridge container B ′ is formed with a support member D ′ (not shown) extending vertically in the center of the cross section of the cartridge container B ′. The support member D ′ has an indicator electrode 4, a counter electrode 5, and a temperature sensor. 7 is supported. The indicator electrode 4 is attached to the lower end of the support member D ′, and the position thereof is adjusted so that the end surface of the tip of the support electrode 4 is close to the diaphragm 2. The counter electrode 5 is attached to a side surface of the support member D ′ at a position away from the indicator electrode 4. The temperature sensor 7 is attached to the lower end of the support member D ′, and its position is adjusted so as to be suitable for measuring the temperature of the diaphragm 2.

  The cables 61a and 61b constitute the cable 61 in the first embodiment. The cables 62a and 62b constitute the cable 62 in the first embodiment. Cables 61 a and 62 a are wired to the connector 16 from the indicator electrode 4 and the counter electrode 5, respectively. Cables 61 b and 62 b connected to the ammeter 8 are wired in the receptacle 16. When the cartridge container B 'is connected to the receptacle 16, the cable 61a and the cable 61b and the cable 62a and the cable 62b are connected via the connector 16, respectively. Thus, when the cartridge container B ′ and the receptacle 16 are connected, the indicator electrode 4 and the counter electrode 5 are connected via the cables 61 a, 61 b, 62 a, 62 b and the ammeter 8.

  Similarly, a cable 71 a is wired from the temperature sensor 7 to the connector 15, and a cable 71 b connected to the oxygen concentration calculation unit 9 is wired to the receptacle 16. When the cartridge container B ′ is connected to the receptacle 16, the cables 71 a and 71 b are connected via the connector 16. The connector 16 is waterproof.

The cartridge 100 is composed of the cartridge container B ′, the diaphragm 2, the reagent 3, the indicator electrode 4, the counter electrode 5, the temperature sensor 7, the cables 61a, 61b, 71a, and the connector 16. After the cartridge 100 is connected to the receptacle 16, the cartridge 100 is held with respect to the container A by a support member C ′ (not shown) so that the bottom wall of the cartridge container B ′ is in contact with the measurement liquid 1.

  The display unit 14 displays the dissolved oxygen amount DO calculated by the oxygen concentration calculation unit 9 and the consumption amount of the reagent 3. Further, the due date D input from the prediction unit 12 is displayed as the next replacement date of the cartridge 100. Other configurations are the same as those of the first embodiment.

  The present embodiment is configured as described above, and the diaphragm 2, the reagent 3, the indicator electrode 4, the counter electrode 5, the temperature sensor 7 and the like are formed into cartridges, so that the cartridge 100 can be replaced when the reagent 3 is consumed. is there. The reagent 3 is often a powerful drug like the potassium hydroxide of this example. If the user performs the replacement or filling operation of the reagent 3 himself, there is a risk that the reagent 3 may adhere to the skin. By using the cartridge as in the present embodiment, it is possible to avoid the user from directly replacing and filling the reagent 3.

  In addition, in the present Example and the said Example 1, although the measurement liquid 1 was accommodated in the container A, the measurement liquid 1 does not necessarily need to be accommodated in the container. The electrochemical sensor of the present invention can also be applied to the case where seawater, river water, sewage, or the like is directly measured.

FIG. 1 is a diagram showing a first embodiment according to the present invention. FIG. 2 is a diagram showing a time change of the oxidation-reduction current I. FIG. FIG. 3 is a block diagram showing the oxygen concentration calculator 9 and the consumption calculator 10. FIG. 4 is a diagram illustrating a second embodiment. FIG. 5 is a diagram showing a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measurement liquid 2 Diaphragm 3 Reagent 4 Indicator electrode 5 Counter electrode 6a, 6b Cable 7 Temperature sensor 8 Ammeter 9 Oxygen concentration calculation part 11 Consumption calculation part 12 Prediction part 13 Display part

Claims (8)

Electrochemical reaction between the electrodes placed in the measurement target or reagent, and the physical quantity of the measurement target is measured by detecting the current or voltage generated between the electrodes, and the reagent consumes the reagent during the measurement. In the sensor
An electrochemical sensor comprising: a consumption calculation unit that calculates an integrated value of the current or voltage and calculates a consumption amount or a residual amount of the reagent based on the integrated value. A diaphragm that separates the measurement target from the reagent;
An indicator electrode disposed in the reagent and disposed in proximity to the diaphragm;
A counter electrode disposed via the reagent between the indicator electrode and
An ammeter for detecting a current flowing between the indicator electrode and the counter electrode;
In an electrochemical sensor for measuring a physical quantity of the measurement object,
An electrochemical sensor comprising: a consumption calculating unit that calculates an integrated value of current values detected by the ammeter and calculates a consumption amount or a residual amount of the reagent based on the integrated value. A cartridge container containing the reagent, the diaphragm, the indicator electrode, and the counter electrode;
The electrochemical sensor according to claim 2, further comprising a receptacle detachably attached to the cartridge container.   The electrochemical sensor according to any one of claims 1 to 3, wherein the consumption calculation unit outputs a signal indicating the consumption or remaining amount of the reagent.   5. The electrochemical sensor according to claim 1, wherein the consumption amount calculation unit outputs a signal indicating the consumption of the reagent when the consumption amount of the reagent exceeds a predetermined value. 6.   2. The apparatus according to claim 1, further comprising: a prediction unit that predicts a time when the amount of consumption of the reagent exceeds a predetermined value based on an output of the consumption amount calculation unit and an elapsed time from the use start time of the reagent. The electrochemical sensor according to any one of 5.   The electrochemical sensor according to claim 6, further comprising a display unit that displays at least one of a consumption amount or a residual amount of the reagent or a time when the consumption amount of the reagent exceeds a predetermined value.   The electrochemical sensor according to claim 1, wherein the physical quantity to be measured is an amount of dissolved oxygen.

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