JPH0225144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a residual chlorine meter that measures the concentration of residual chlorine contained in tap water or the like.

As a conventional example of such a residual chlorine meter, a residual chlorine meter having the configuration shown below is known. That is, when a rotating electrode made of platinum or the like and a comparison electrode made of silver or the like are inserted into a test liquid such as water, and a predetermined voltage is applied from the outside between the rotating electrode and the comparison electrode, the rotating electrode A reduction reaction occurs, an oxidation reaction occurs at the reference electrode, and an electrolytic current flows between the rotating electrode and the reference electrode. Since the electrolytic current has a correlation with the concentration of residual chlorine contained in the test liquid, the concentration of residual chlorine contained in the test liquid can be determined by detecting the electrolytic current. Further, the electrolytic current is configured to flow through a signal line connected to the rotating electrode via a contact portion made of a liquid metal such as Hg or a mechanical contact portion such as a brush contact.

However, in the above conventional example, when the contact part is made of liquid metal, Hg, which is liquid metal, is used.
etc. are often prohibited from use because they are highly toxic to the human body, and in cases where they have the mechanical contact parts described above, poor contact occurs in the mechanical contact parts as the rotating electrode rotates. However, there were drawbacks such as the inability to accurately detect the electrolytic current.

The present invention has been made in view of these drawbacks, and its purpose is to always accurately detect the electrolytic current without having contact parts made of highly toxic liquid metal or mechanical contact parts that are likely to cause poor contact. An object of the present invention is to provide a residual chlorine meter that can accurately measure residual chlorine concentration.

Hereinafter, the present invention will be explained in detail using figures. The figure is an explanatory diagram of the structure of an embodiment of the present invention, and in the figure, 1 is an indicator electrode made of platinum or gold in the form of a spot, 2 is a comparison electrode made of silver chloride, etc., and 3 is a comparative electrode made of silver chloride or the like.
1 is a rotating electrode in which an indicator electrode 1 and a comparison electrode 2 are respectively attached to predetermined parts; 4 is a drive motor; 5 is a first gear rotated by the drive motor 4;
The drive motor 4 rotates while meshing with the first gear.
While reducing the rotational speed of the rotating electrode 3 at a predetermined ratio,
7 is a transmission amplifier section; 8 is a second gear that rotates the
9 and 9' are a reception amplifier section, and 9 and 9' are DC power supply sections that are arranged at a predetermined portion around the reception amplifier section 8 and apply a DC voltage to a coil wound around a DC magnet to generate a predetermined magnetic field. 10 is a liquid tank; 11 is a sphere made of a glass bulb or the like housed in the liquid tank 11; 12a and 12b are inlets and outlets for the liquid to be measured; 13
a is the liquid to be measured introduced from the inlet 12a, 13
A fluid b is composed of the liquid to be measured that overflowed in the liquid tank 10 and is led out from the outlet 12b.
The transmission amplifier 7 also includes a first amplifier 71 that amplifies the output signal of the rotating electrode 3, and a pulse width modulator 7 that pulse width modulates the output signal of the amplifier 71.
2. Moving in the predetermined magnetic field generated by the light emitting element 73 which receives the output signal of the pulse width modulator 72 and emits an optical signal according to the output signal, and the DC power supply units 9 and 9'. The generator coils 74 and 74' generate an induced current, and the induced current is rectified and supplied to the first amplifier 71 in the transmitting amplifier 7, the pulse width modulator 72, and the rotating electrode 3. It plays the role of a DC power supply that supplies each drive voltage, etc. Furthermore, the receiving amplifier 8 includes a light receiving element 81 that receives the optical signal emitted from the light emitting element 73 of the transmitting amplifier 7;
A second amplifier 82 that amplifies the output signal of the light receiving element 81, and a display section 83 that receives the output signal of the amplifier 82, performs predetermined arithmetic processing, and displays the residual chlorine concentration in the liquid to be measured 13a. It is configured. Note that the transmission amplifier 7 is integrally coupled with the rotating electrode 3 and is configured to be rotated by a gear 6 at a rotation speed having a predetermined ratio to the rotation speed of the drive motor 4. Further, the shape and arrangement position of the DC power supply sections 9, 9' are not limited to those shown in the drawings, and various modifications can be made within the range of the configuration capable of generating the above-mentioned predetermined magnetic field. For example, It is also possible to arrange it only at the position 9' in the figure.

The operation of the embodiment of the present invention will be explained below.
In the figure, the liquid to be measured introduced from the inlet 12a fills a liquid tank 10, and the overflow in the liquid tank 10 is led out from the outlet 12b as a fluid 13b. On the other hand, when the drive motor 4 rotates, the rotation is reduced to a predetermined ratio and transmitted to the rotating electrode 3 via the first and second gears 5 and 6.
When the rotating electrode 3 is rotated, the particles 11 begin to move within the liquid tank 10, and the surface of the rotating electrode 3 is cleaned, and the liquid to be measured is sufficiently stirred. Further, the transmitting amplifier 7 also rotates together with the rotating electrode 3, and the generating coils 74, 74' move in the magnetic field generated by the DC power supplies 9, 9', causing the induced current to flow. is generated, and a predetermined voltage (usually converted to a desired voltage by a power supply circuit, not shown) based on the induced current is applied to each drive voltage of the first amplifier 71 and pulse width modulator 72, as well as the indicator electrode 1 and They are respectively supplied as applied voltages applied between the comparison electrodes 2. When the applied voltage is applied as an external voltage between the indicator electrode 1 and the comparison electrode 2, the voltage between the indicator electrode 1 and the comparison electrode 2 changes depending on the residual chlorine concentration contained in the liquid to be measured in the liquid tank 10. A detection current flows between the two. The detected current is transmitted to the transmitting amplifier 7.
The signal is amplified by a first amplifier 71 within the same circuit, pulse-width modulated by a pulse-width modulator 72, and then converted into an optical signal by a light-emitting element 73.
The optical signal is received by the light-receiving element 81 of the receiving amplifier 8 and converted into an electrical signal, and the output signal of the light-receiving element 81 is amplified by the second amplifier 82, and then predetermined arithmetic processing is performed on the display section 83. The residual chlorine concentration is calculated and displayed as the residual chlorine concentration in the liquid to be measured. Although not shown, the drive motor 4, the DC power supplies 9, 9', the second amplifier 82 of the light-receiving amplifier 8, and the display unit 8 each have a built-in power supply that supplies the necessary drive voltage, or is now being supplied from outside.

According to the embodiment of the present invention as described in detail above, since there is no mechanical contact part in the signal line as in the conventional example, the drawbacks of the conventional example caused by the mechanical contact part are completely eliminated. It has the advantage of being In addition, since it does not have contact parts with liquid metals such as Hg, the use of the product may be prohibited due to the parts used being highly toxic to the human body, as in the conventional example. do not have. Furthermore, since the power supply section is electromagnetically coupled and the signal line is optically coupled, there is no need to pay particular attention to insulation between signal input and output, and there is also the advantage that it is resistant to external electrical noise. Although the case where the power supply section is electromagnetically coupled and the signal line is optically coupled has been described in detail above, it is also possible to easily employ electromagnetic coupling or optical coupling for both the power supply section and the signal line, and the same effect can be obtained.

[Brief explanation of drawings]

The figure is a configuration explanatory diagram of an embodiment of the present invention. 1... Indicator electrode, 2... Comparison electrode, 3... Rotating electrode, 4... Drive motor, 5, 6... Gear, 7...
Transmitting amplifier, 8...Receiving amplifier, 9, 9'...DC power supply section, 10...Liquid tank, 11...Particle, 12
a, 12b... Lead-out port, 13a... Measured object,
13b...Fluid, 71, 81...Amplifier, 72...
... Pulse width modulator, 73, 81 ... Optical element, 83
...Display section, 74, 74'...Generating coil.

Claims (1)

[Claims] 1. A rotating electrode including an indicator electrode and a comparison electrode each attached to a predetermined portion, a transmitting amplifier that is integrally coupled with the rotating electrode and rotates and optically modulates an output signal from the rotating electrode, and the transmitting amplifier. a DC power supply unit that is electromagnetically coupled with the transmitting amplifier and supplies a necessary voltage source to the transmitting amplifier and the rotating electrode by electromagnetic induction; A residual chlorine meter comprising: a receiving amplifier that calculates and displays a residual chlorine concentration; and a drive motor that rotates the rotating electrode and the transmitting amplifier via a predetermined gear.