JP2007113985A - Oxidation-reduction potential measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an oxidation-reduction potential measuring instrument capable of measuring oxidation-reduction potential (ORP) at a specified measuring position (distance from the surface of bottom sludge), by detecting the interface of bottom sludge/water. <P>SOLUTION: In the oxidation-reduction potential measuring instrument, equipped with a plurality of working electrodes provided in the axial direction of a rod-shaped electrode holder at a predetermined interval, an interface detecting electroconductivity measuring circuit for detecting the interface of bottom sludge/water using a plurality of the working electrodes is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

In rivers and lakes, the bottom mud consumes dissolved oxygen, the bottom of the water becomes anaerobic, and phosphorus, iron, manganese, etc. are eluted from the bottom mud, causing a load on the water environment.
In such a state, the oxidation-reduction potential (ORP) in the bottom mud and the water directly above the bottom mud changes to the negative side. By measuring such a change, it becomes possible to grasp the environmental change and the pollution state. .
The present invention relates to an oxidation-reduction potential measuring apparatus capable of measuring an oxidation-reduction potential (ORP) specifying a measurement position (distance from the mud surface) by detecting a bottom mud / water interface.

  Prior art documents related to the oxidation-reduction potential measuring apparatus include the following.

Japanese Utility Model Publication No. 5-057544

FIG. 6 is a diagram illustrating the configuration of a conventional example.
In FIG. 6, the base 1 is made of a vinyl chloride disk having a diameter of 40 cm and a thickness of 2 cm, and an insertion port through which the electrode holder 2 is inserted and supported is formed in the center of the base 1.
A thin rod-shaped electrode holder 2 formed of a stainless steel pipe having a length of 53 cm and an outer diameter of 1 cm formed at the tip 3 having a sharp end is detachable in the orthogonal direction with the tip 3 being down. It is inserted and supported.

Along the length direction of the electrode holder 2, one working electrode 4 and four working electrodes 4a, 4b are attached in sequence to the bottom of the base 1 (at the tip 3 side). That is, the working electrodes 4a and 4b made of platinum are sealed in the opening formed in the outer wall of the electrode holder 2 by rubber packing and sealed so that water does not leak inside, and fixed with an adhesive. It is.
The outer surfaces of these working electrodes 4a and 4b are attached almost flat so that there is no unevenness with respect to the outer periphery of the electrode holder 2, and lead wires are connected to the inner sides thereof.

Each of the working electrodes 4a and 4b has a circular shape with an outer diameter of 8 mm, and the bottom mud working electrode 4a under the base 1 is provided at a distance of 5 cm from the bottom surface 2 cm of the base 1 and is therefore the largest. The lower working electrode 4a has a depth of 17 cm from the lower surface of the substrate 1. A working electrode 4b for water on the base 1 is provided immediately above the base 1.
A normal reference electrode 5 is detachably inserted and supported in a through-hole provided in the corner of the base 1. Further, around the electrode holder 2 in the center of the base 1, three iron weights 6 for weight adjustment are placed evenly in the recesses of the base 1, and the total weight is adjusted to 12 kg.

A measuring unit (not shown) for measuring the oxidation-reduction potential by the working electrodes 4a and 4b and the comparison electrode 5 is provided separately from the base 1 and the electrode holder 2, and a plurality of working electrodes 4a and 4b are simultaneously attached. Alternatively, a mechanism that can measure the oxidation-reduction potential while sequentially switching is provided.
The lead wires of the working electrodes 4a and 4b and the lead wire of the comparison electrode 5 are connected to the respective cables 7, and the cable 7 is further connected to the measuring section.

  In the above configuration, the redox potential of the bottom mud is measured for each depth with the working electrodes 4a and 4b and the comparison electrode 5 supported on the base 1.

Such an apparatus has the following problems.
By covering the bottom mud surface where the redox potential (ORP) is to be measured with the base, the oxygen supply from the water is cut off and the original redox potential (ORP) at the measurement point cannot be measured.

  The change in bottom mud oxidation-reduction potential (ORP) due to anaerobic conditions is at most 5-10 cm in the depth direction, so we want to measure at intervals of 10 mm or less, but the actual bottom mud undulation is larger than this, The mud / water interface was not clear and I did not know which position I was measuring.

  The object of the present invention is to solve the above-mentioned problems, and by detecting the bottom mud / water interface, the redox potential (ORP) can be measured by specifying the measurement position (distance from the mud surface). An object of the present invention is to provide a redox potential measuring apparatus capable of

In order to achieve such a problem, in the present invention, in the oxidation-reduction potential measuring device according to claim 1,
In the oxidation-reduction potential measuring apparatus having a plurality of working electrodes provided at predetermined intervals in the axial direction of the rod-shaped electrode holder, the interface detection conductivity measurement for detecting the interface using the plurality of working electrodes. A circuit is provided.

In the oxidation-reduction potential measurement apparatus according to claim 2 of the present invention, the oxidation-reduction potential measurement apparatus according to claim 1,
An electrode switching circuit for selecting an electrode to be used among the plurality of working electrodes is provided.

In the oxidation-reduction potential measuring device according to claim 3 of the present invention, the oxidation-reduction potential measuring device according to claim 1 or 2,
The working electrode is embedded in the peripheral surface of the electrode holder, respectively.

In the oxidation-reduction potential measuring device according to claim 4 of the present invention, the oxidation-reduction potential measuring device according to any one of claims 1 to 3,
The working electrode is provided in a ring shape on the peripheral surface of the electrode holder.

In the oxidation-reduction potential measuring device according to claim 5 of the present invention, the oxidation-reduction potential measuring device according to any one of claims 1 to 2,
The working electrode is a pin-like electrode provided orthogonal to the axis of the electrode holder.

In the oxidation-reduction potential measuring device according to claim 6 of the present invention, the oxidation-reduction potential measuring device according to any one of claims 1 to 5,
The electrode holder is supported by a ring-shaped substrate whose one surface is in contact with the bottom mud.

According to claim 1 of the present invention, there are the following effects.
Since the electrode position of the conductivity sensor for detecting the interface with the oxidation-reduction potential (ORP) sensor is the same, the position of the bottom mud / water interface can be specified easily and accurately. By detecting, an oxidation-reduction potential measuring device capable of measuring an oxidation-reduction potential (ORP) specifying a measurement position (distance from the mud surface) is obtained.

According to claim 2 of the present invention, there are the following effects.
Since an electrode switching circuit for selecting an electrode to be used from among the plurality of working electrodes is provided, an inexpensive oxidation-reduction potential measurement device that does not require a measurement circuit for each electrode can be obtained.

According to claim 3 of the present invention, there are the following effects.
Since the working electrode is embedded in the peripheral surface of the electrode holder, there is little disturbance to the bottom mud, and a highly accurate redox potential measuring device can be obtained.

According to claim 4 of the present invention, there are the following effects.
Since the working electrode is provided in a ring shape on the peripheral surface of the electrode holder, a highly reliable oxidation-reduction potential measuring device with high measurement accuracy can be obtained.

According to claim 5 of the present invention, there are the following effects.
Since the working electrode is a pin-like electrode provided orthogonal to the axis of the electrode holder, it is easy to manufacture and an inexpensive redox potential measuring device can be obtained.

According to claim 6 of the present invention, there are the following effects.
Since the electrode holder is supported by a ring-shaped base that is in contact with the bottom mud, it does not cover the periphery of the electrode holder with the base so that the supply of oxygen to the periphery of the electrode is not affected. Therefore, a highly accurate redox potential measuring device can be obtained.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view showing the configuration of the main part of one embodiment of the present invention, and FIG. 2 is a block diagram of an electric circuit of the main part of FIG.

In FIG. 1, a plurality of working electrodes 11a, 11b, 11c,... Are provided at predetermined intervals in the axial direction of the rod-shaped electrode holder 12.
In this case, the electrode holder 12 is supported by a ring-shaped base 13 whose one surface is in contact with the bottom mud. The reference electrode 14 is also supported by the base 13.

As shown in FIG. 2, the electrode switching circuit 21 selects an electrode to be used among the plurality of working electrodes 11a, 11b, 11c.
The measurement selection circuit 22 switches between the oxidation-reduction potential measurement circuit 15 and the interface detection conductivity measurement circuit 16.

In the above configuration, the oxidation-reduction potential measuring circuit 15 measures the oxidation-reduction potential of the bottom mud for each depth using the working electrodes 11a, 11b, 11c... And the comparison electrode 14 supported by the base 13.
On the other hand, the position of the bottom mud is detected by the interface detection conductivity measuring circuit 16.

In other words, the working electrodes 11a, 11b, 11c,... Of the oxidation-reduction potential (ORP) sensor also function as measurement electrodes of the conductivity sensor to realize interface detection by measuring conductivity.
The oxidation-reduction potential (ORP) sensor has a configuration of a reference electrode 14 and a working electrode (metal) 11a, 11b, 11c..., And the conductivity sensor has at least two measurement electrodes (metals) 11a, 11b, 11c. Therefore, the metal electrode part can be shared.

Different conductivity is shown for reasons such as different components and concentrations in water and bottom mud. Therefore, when the redox potential (ORP) / conductivity composite sensor is installed on the bottom of the water, the conductivity greatly changes when the working (measurement) electrodes 11a, 11b, 11c,. The interface position is recognized by knowing the position, and the redox potential (ORP) in the vertical direction is measured with reference to the interface position.
Reference numeral 17 denotes an electrode cable, and 18 denotes bottom mud.

As a result,
Since the electrode position of the conductivity sensor for detecting the interface with the oxidation-reduction potential (ORP) sensor is the same, the position of the bottom mud / water interface can be specified easily and accurately, and the bottom mud / water interface is detected. By doing so, an oxidation-reduction potential measuring apparatus capable of measuring the oxidation-reduction potential (ORP) specifying the measurement position (distance from the mud surface) is obtained.

  Further, since the electrode switching circuit 21 for selecting the electrode to be used among the plurality of working electrodes 11a, 11b, 11c... Is provided, there is no need to provide a measuring circuit for each working electrode 11a, 11b, 11c. An inexpensive oxidation-reduction potential measuring device can be obtained.

  Further, since the electrode holder 12 is supported by a ring-shaped base 13 whose one surface is in contact with the bottom mud, the periphery of the electrode holder 12 is not covered with the base, so that the working electrodes 11a, 11b, 11c. It is possible to prevent the supply of oxygen to the gas, and to obtain a highly accurate redox potential measuring device.

FIG. 3 is an explanatory view of the main part configuration of another embodiment of the present invention.
In the present embodiment, the working electrodes 31a, 31b, 31c,... Are embedded in the peripheral surface of the electrode holder 32, respectively.

  As a result, the working electrodes 31a, 31b, 31c,... Are embedded in the peripheral surface of the electrode holder 32, so that a highly accurate oxidation-reduction potential measuring device with little disturbance to the bottom mud can be obtained.

FIG. 4 is an explanatory view of the main part configuration of another embodiment of the present invention.
In this embodiment, the working electrodes 41 a, 41 b, 41 c... Are provided in a ring shape on the peripheral surface of the electrode holder 32.

  As a result, since the working electrodes 41a, 41b, 41c,... Are provided in a ring shape on the peripheral surface of the electrode holder 42, an oxidation-reduction potential measuring device with high measurement accuracy and high reliability can be obtained.

FIG. 5 is an explanatory view of the main part configuration of another embodiment of the present invention.
In the present embodiment, the working electrodes 51 a, 51 b, 51 c... Are pin-like electrodes provided orthogonal to the axis of the electrode holder 52.

  As a result, the working electrodes 51a, 51b, 51c,... Are pin-shaped electrodes provided orthogonal to the axis of the electrode holder 52, so that an inexpensive redox potential measuring device that is easy to manufacture can be obtained. .

  As a circuit for measuring conductivity / redox potential (ORP) with a plurality of working (measuring) electrodes, a method other than the method of realizing multipoint measurement by switching the electrodes to be measured at the input of the measuring circuit as shown in FIG. Of course, as many measuring circuits as the actual number of working (measuring) electrodes may be prepared.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

It is principal part structure explanatory drawing of one Example of this invention. It is a principal part electric circuit block diagram of FIG. It is principal part structure explanatory drawing of the other Example of this invention. It is principal part structure explanatory drawing of the other Example of this invention. It is principal part structure explanatory drawing of the other Example of this invention. It is structure explanatory drawing of a prior art example.

Explanation of symbols

11a Working electrode 11b Working electrode 11c Working electrode 11d Working electrode 12 Electrode holder 13 Base 14 Reference electrode 15 Redox potential measuring circuit 16 Conductivity measuring circuit for interface detection 17 Cable 18 Bottom mud 21 Electrode switching circuit 22 Measurement selection circuit 31a Action Electrode 31b Working electrode 31c Working electrode 31d Working electrode 32 Electrode holder 41a Working electrode 41b Working electrode 41c Working electrode 41d Working electrode 42 Electrode holding body 51a Working electrode 51b Working electrode 51c Working electrode 51d Working electrode 52 Electrode holding body

Claims (6)

In the oxidation-reduction potential measuring device comprising a plurality of working electrodes provided at predetermined intervals in the axial direction of the rod-shaped electrode holder,
An oxidation-reduction potential measuring apparatus comprising an interface detection conductivity measuring circuit that detects an interface using the plurality of working electrodes. The oxidation-reduction potential measuring device according to claim 1, further comprising an electrode switching circuit that selects an electrode to be used among the plurality of working electrodes. The oxidation-reduction potential measuring device according to claim 1 or 2, wherein the working electrode is embedded in a peripheral surface of the electrode holder. The oxidation-reduction potential measuring device according to any one of claims 1 to 3, wherein the working electrode is provided in a ring shape on a peripheral surface of the electrode holder. The oxidation-reduction potential measuring device according to any one of claims 1 to 2, wherein the working electrode is a pin-like electrode provided orthogonal to the axis of the electrode holder. The oxidation-reduction potential measuring device according to any one of claims 1 to 5, wherein the electrode holder is supported by a ring-shaped substrate whose one surface is in contact with bottom mud.

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