JPH0342788B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a PH meter sensor that continuously detects the PH concentration of a liquid to be measured.

<Conventional technology> Conventionally, in order to immerse the electrode part of such a PH meter sensor in the liquid to be measured, a sealing gasket and a set screw are used to lock a predetermined part of the electrode of the PH meter sensor to a holder. There were many. in this case,
If the set screws were tightened too tightly, the gasket would tend to thermally expand at high temperatures, and the glass tube, which is the main body of the electrode, would often break. Therefore, the set screw has to be tightened gently with some allowance, and the gasket can only be made of rubber-based material (for example, Viton, etc.).
However, if a rubber-based material is used for the gasket, if the liquid to be measured is a corrosive solution such as a strongly acidic or strongly oxidizing solution, the gasket may not have sufficient corrosion resistance against the liquid to be measured. There was an inconvenience. As described above, the conventional PH meter sensor had a major drawback in terms of sealability.

In addition, in the conventional PH meter sensor described above, a KCl solution is supplied from a KCl (potassium chloride) supply tank to a reference electrode through a KCl supply tube, and the KCl solution is introduced into the liquid to be measured in small amounts from a ceramic liquid junction. It is starting to leak into the country. When air bubbles accumulate in the KCl replenishment tube, it becomes extremely difficult to remove the air bubbles, and there is a problem in that the air bubbles prevent the outflow of the KCl solution. For this reason, a PH meter sensor with a removable liquid junction type is also commercially available, but the electrode body of this sensor is a non-vitreous tube and has a drawback of poor corrosion resistance. In this way, conventional PH
The sensor had major drawbacks in terms of KCl solution replenishment and corrosion resistance.

Furthermore, in the conventional PH meter sensor mentioned above, when the liquid to be measured is at high pressure, the chick to be measured flows back into the electrode through the liquid junction, so it is necessary to prevent such backflow and force the KCl solution A constant pressure was applied to the KCl replenishment tank in order to cause the KCl to flow out into the liquid to be measured. At this time, it was necessary to firmly tighten the connection between the KCl replenishment tube and the electrode, but if the connection was too strong, the glass at the electrode part would break. For this reason, compressed air or the like is added to both the KCl supply tank and the chamber (the chamber in which the upper part of the PH meter sensor, etc. is stored). However, the cable for transmitting and receiving electrical signals to and from the electrode portion and the KCl replenishment tube must be led out of the chamber in an airtight manner, which has the disadvantage of impairing maintainability. As described above, conventional PH meter sensors have various drawbacks in use even when the liquid to be measured is at high pressure.

By the way, in the conventional PH meter sensor, a liquid earth electrode, a reference electrode, a glass electrode, and a temperature compensator were initially configured individually. After that, +
, ++, ++, or ++
So-called composite electrodes, which are combined like +, have become commercially available. However, in the case of composite electrodes such as + or ++, the cable becomes two or has a bifurcated structure.
The disadvantage was that the structure became complicated. Also, ++
Composite electrodes such as , or +++, in which the main body of the electrode part is made of glass, have not yet been put to practical use. For this reason, PH meter sensors that do not require a liquid earth are also available on the market, but
When the number to be measured has a potential or when the liquid junction is dirty and has a high resistance, it has the disadvantage that it is susceptible to noise and has poor noise resistance. As described above, the conventional PH meter sensor also has a drawback in terms of liquid earthing.

<Object of the Invention> The present invention has been made in view of the various drawbacks mentioned above, and its purpose is to provide a PH meter sensor that solves the above-mentioned drawbacks at once, has a simple configuration, and is excellent in maintainability. Our goal is to provide the following.

<Summary of the Invention> The present invention is characterized in that a PH meter sensor includes a main body having a flange made of the same material as the lower cylinder in the body, a reference electrode, a glass electrode, a liquid earthing means, and a resistance temperature detector. and a pressure-resistant flow path through which the electrolyte solution flows is provided in the main body.

<Example> Hereinafter, the present invention will be described in detail using figures. FIG. 1 is a cross-sectional view of the configuration of an embodiment of the present invention.
In the figure, 1 is a cylinder made of a glass tube such as a soda potash lead glass tube, and 1a is a flange made of the same material as the cylinder 1 and integrally formed with the cylinder 1.
1' is a cylindrical cap having an adhesive 2 filled inside and forming the main body of the PH meter sensor together with the cylindrical body 1;
3 is a gasket that watertightly partitions the inside of the PH meter sensor body formed by the cylindrical body 1 and the cylindrical cap 1';
4 is a tube for introducing an electrolyte solution such as a KCl (potassium chloride) solution, 5 is a tube holder that holds the tube 4 in a watertight manner, and 6 is a pipe made of, for example, a stainless steel pipe connected to the tube 4 by the tube holder 5. , 7 is a flexible tube connected to the pipe 6 and through which the electrolyte solution flows;
8 is a reference electrode composed of an electrolyte solution 81 supplied through the tube 7 or the like, an internal electrode 82 immersed in the solution, and a liquid junction 83 made of, for example, ceramic; 9 is the vicinity of the liquid junction 83; A glass electrode 10 having a sensitive part 91 arranged in the inner electrode 82 and the glass electrode 9 is connected via a connector 10c to cables 10a and 10b covering core wires connected to the internal electrode 82 and the glass electrode 9, respectively, and is connected to an external converter, etc. (not shown), the other end of which is connected to a cable, 1
1 and 11' are O-rings, 12 is an electrolyte solution outlet, 13 is a holder, and 13' is a set screw.
FIG. 2 is a partially cutaway view taken along the line A-A' in FIG. 1. In the figure, the same symbols as in FIG. 1 are used with the same meanings, and redundant explanation will be omitted here. Further, 6' and 7' are pipes and tubes similar to the pipe 6 and tube 7 in FIG. A temperature sensing resistor, 16, was deposited in the electrolyte solution discharge channel.
Clean the KCl crystals, for example with a tube made of Teflon. FIG. 3 is a schematic explanatory diagram of a main part taken along the line B-B' in FIG. 1. In the figure, the same symbols as in FIG. 1 are used with the same meanings, and redundant explanation will be omitted here. Further, 17 is an introduction pipe through which the electrolyte solution is introduced via tube 7 etc. in FIG. 1, and 18
19 is a ratio electrode body which has the liquid junction part 83 at the tip and houses the electrolyte solution 81 and internal electrode 82 (not shown in FIG. 3); This is a discharge tube through which the solution 81 is discharged and guided to the discharge port 12 via the tube 7' in FIG. 2 and the like.

In the embodiment of the present invention having such a configuration, the set screw 1 is inserted from above the flange 1a in FIG.
3', a predetermined portion of the PH meter sensor body is locked to the holder 13. Therefore, a Teflon o-ring can be used as the o-ring 11', and even if the fluid to be measured is a corrosive fluid such as a strong acid, a sufficient seal can be maintained unlike the conventional example. Further, the electrolyte solution introduced from the electrolyte solution supply tank (not shown) via the tube 4 is transferred from the tube holder 5 in Fig. 1 to the pipe 6 to the tube 7 to the inlet pipe 17 in Fig. 3 to the reference electrode. Main body 1
8 -> outlet pipe 19 -> tube 7' in Fig. 2 -> pipe 6', and is discharged to the outside from the outlet 12 as required. If the electrolyte solution is crystallized in the channel leading from the reference electrode body 18 to the pipe 6' and the smooth flow of the electrolyte solution is obstructed, the tube 16 is moved up and down to crush the crystals of the electrolyte solution. removed. Furthermore,
A constant voltage is applied to the internal electrode 82 of the reference electrode 8 and the glass electrode 9 via the core wires in the cables 10a and 10b, so that the PH concentration of the liquid to be measured is detected from the current value flowing between these electrodes. It's getting old. Furthermore, the temperature of the liquid to be measured can be detected by the temperature measuring resistor 15 shown in FIG. 2, and the detected temperature is used to perform temperature compensation for the above-mentioned PH concentration. .

<Effects of the Invention> According to the embodiments of the present invention as described in detail above, a PH meter sensor that solves all the drawbacks of the conventional example, has a simple configuration, and is excellent in maintainability is realized. That is, since the flange 1a made of the same material as the cylinder 1 is provided on the body of the cylinder 1, a Teflon O-ring can be used as the O-ring 11', and it is also effective against corrosive liquids to be measured. Sufficient sealing performance can be ensured. Furthermore, since the electrolyte solution flow path is provided within the electrode, crystals of the electrolyte solution can be removed by the tube 16, and the electrolyte solution can flow smoothly. Furthermore, since the tube holder 5 has a structure that can withstand pressure of 10 kg/cm ² , the electrolyte solution can be supplied at high pressure, and even when the liquid to be measured is under high pressure, the liquid junction can be maintained as in the conventional example. There is no possibility that the liquid to be measured flows back into the electrode through the channel. In addition, since the liquid earth 14 is provided near the glass electrode 9, liquid earth, reference electrode, and
A composite electrode made of glass is realized by combining a glass electrode (or a glass electrode and a temperature compensator).

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the structure of an embodiment of the present invention, Fig. 2 is a partially cutaway view showing the A-A' cross-section of Fig. 1, and Fig. 3 is a main part showing the B-B' cross-section of Fig. 1. It is an overview explanatory diagram. 1... Cylindrical body, 1'... Cylindrical cap, 1a...
Flange, 3... Gasket, 4, 7, 7', 1
6...Tube, 5...Tube presser, 6,6'
... Pipe, 8 ... Reference electrode, 81 ... Electrolyte solution, 82 ... Internal electrode, 83 ... Liquid junction, 9 ...
Glass electrode, 91... Sensing part, 10... Cable, 11, 11'... O-ring, 12... Outlet, 13... Holder, 13'... Set screw, 14
...Liquid earth, 15...Resistance temperature detector, 17...Introduction tube, 18...Reference electrode body, 19...Output tube.

Claims (1)

[Claims] 1. A main body having at least two spaces watertightly partitioned by a partition member and having a flange made of the same material as the lower cylindrical body in the body, and a first space in the first space. a reference electrode consisting of a contained electrolyte solution, an internal electrode, and a liquid junction installed at one end of the cylinder;
The main body includes a glass electrode having a sensitive part near the liquid junction, a liquid earthing means and a temperature measuring resistor provided near the electrode, and a pressure-resistant flow path through which the electrolyte solution flows. A PH meter sensor characterized by being installed in. 2. The PH meter sensor according to claim 1, wherein the lower cylinder and the flange are made of glass. 3. The PH meter sensor according to claim 1 or 2, wherein the electrolyte solution is a potassium chloride solution.