JPH0688796A - Ozone amount measuring system of calibration/comparison balance system - Google Patents

Abstract

PURPOSE:To accurately obtain ozone amount by connecting a series connection of an electrode and an impedance and a series connection of two more sets of impedances in parallel with a power source, and measuring potential differences among the electrode, the impedances and connecting points between the impedances. CONSTITUTION:A voltage V is supplied from power source terminals (d), (e) to an electrode 11 through a resistor 12, and simultaneously supplied to resistors 13, 14 connected in series. Let the resistance values of the resistors 12-14 be R12-R14, voltages to be applied to the resistors 12, 14 be DELTAVi, DELTAVN, and a state before ozone is introduced be denoted by a suffix B. If a polarization current at the time of introducing the ozone is deltai, potential differences DELTAV between connecting points of the resistors 11, 12 and the resistors 13, 14 becomes deltaV= R12deltai+DELTAViB-DELTAVN. When an applied voltage for satisfying balance condition DELTAViB=DELTAVN is DELTAVB and DELTAViB=DELTAVN=deltaVB deltai=(deltaV-deltaVB)/R12 is obtained, and a polarization current can be calculated. Thus, a decomposing current is almost automatically removed from a measured current, and the applied voltage can be suitably set. Accordingly, the ozone amount can be accurately measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone amount measuring method, and more particularly to an ozone amount measuring method having high accuracy and long-term durability.

[0002]

2. Description of the Related Art Conventionally, this type of device has measured the amount of ozone introduced into potassium iodide by directly measuring the polarization current. It is necessary to subtract and calculate the electrolytic current,
The electrolytic current may be 50% or more of the measured current, and may reach 80% depending on the measured ozone amount.

As a result, the current measurement error is amplified, and in addition, since the total amount of the polarization current should be measured, the long-term stability of the characteristics due to the chemical reaction on the electrode surface is impaired depending on the polarization current. There is a drawback that.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art, suppress amplification of current measurement error, and obtain highly accurate ozone amount measurement results.
By measuring a part of the polarization current, it is possible to reduce the impact on the electrode surface and provide a method to ensure long-term stability of the measuring device.

[0005]

According to the present invention, most of the electrolysis current is automatically removed from the measurement current, and the characteristics of iodine whose input weight has been measured and the measurement current are used as calibration values. , It is configured to allow partial measurement of the polarization current.

[0006]

[Example] In Fig. 1, reference numeral 1 denotes an ozone reaction tower in which a potassium iodide solution having a predetermined concentration is stored. Reference numeral 3 is a container in which the electrode 2 is housed, and a potassium iodide solution is circulated by a pump 4 via a connecting pipe 6. Reference numeral 5 is a diffuser ball into which ozone-mixed gas to be measured is introduced via a connecting pipe 7. A and B are electrode terminals, which are connected to a power source, and usually the drop voltage of the resistor 8 is measured and the polarization current is measured.

FIG. 2 is a model diagram of an inter-electrode applied voltage V (usually a DC voltage) and an inter-electrode current i according to a conventional general method.
9 is the electrolytic current of the potassium iodide solution, 10 is the measured current when ozone is introduced, and this difference is the total amount of the polarization current that indicates the amount of introduced ozone, which is theoretically irrelevant to the applied voltage. Need a voltage of.

FIG. 3 shows the ozone amount measuring method according to the present invention, in which the applied voltage V is supplied through the power terminals D and E. 1
1 shows the electrode 2 of FIG. 1, and impedances 12-14
Are arranged, and ΔV and δV shown in the figure are measured.

A non-linear resistance is generally present between the electrodes 2.
Therefore, it is desirable that the resistors 12 to 14 also have non-linear resistance,
Even a linear resistor can be used practically. Now, when the state before introducing ozone is displayed with a suffix B and the polarization current at the time of introducing ozone is indicated by δi, the following is established. However, NO is suffixed to each resistor.

[0010]

[Equation 1]

As a balance condition, the applied voltage for which ΔV _iB = ΔV _N is displayed as ΔV _B, and considering the deviation of the applied voltage, ΔV _iB
When −ΔV _N = δV _B , the polarization current δi is calculated as follows.

[0012]

[Equation 2]

As described above, since δV _B ≈0, the amplification of the error in the measurement error of δV _B to the polarization current δi is very small, and when the setting is 100%, the impact of the above error is “zero”. Becomes

In FIG. 4, instead of introducing ozone as shown in FIG. 1, gravity-measured iodine (actually dissolved in potassium iodide solution) weight m _I2 was added, and δ was measured under the same conditions.
The calibration characteristics obtained by measuring i are shown in 15, and the ozone reaction equation

[0015]

[Equation 3]

From the above, the amount of ozone can be calculated.

By using this calibration, it is not necessary to measure the applied voltage above the point C shown in FIG.
By properly setting _B , the impact of the polarization current on the electrode can be greatly reduced.

[0018]

[Advantages of the Invention] By adopting the calibration / comparison balance method,
The amount of ozone can be measured with high accuracy.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the present invention.

FIG. 2 is a model diagram of a conventional method.

FIG. 3 is a circuit diagram of the present invention.

FIG. 4 is a model diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Ozone reaction tower 2 Electrode 3 Container 4 Pump 5: Air diffuser balls 6, 7: Connection tube 8: Resistor 9: Electrolysis Current 10 ・ ・ ・ ・ ・ ・ Measurement current 11 ・ ・ ・ ・ ・ ・ Electrodes 12-14 ・ ・ Resistor 15 ・ ・ ・ ・ ・ ・ Calibration characteristics

Claims (1)

[Claims] 1. The amount of ozone is utilized by utilizing the chemical reaction between the protruding iodine based on the chemical reaction between ozone and potassium iodide in a potassium iodide solution and the hydrogen molecule generated by the polarization phenomenon on the surface of the charging electrode. In the method of measuring, the impedance is connected to one end of the electrode, the other end is connected to one end of the power supply, the other end of the electrode is connected to the other end of the power supply, and at least two sets of impedances are connected between the power supplies. By connecting in series and measuring the potential difference between the connection point of the impedance and the connection point of the electrode and the impedance,
A method of measuring the amount of ozone by a calibration / comparison balance method characterized by measuring the amount of ozone.