公开(公告)号：JPH05232082A

公开(公告)日：1993-09-07

申请号：JP6932492

申请日：1992-02-20

Applicant: TOA ELECTRONICS

Inventor： MORITA KENICHI ,  FURUYA ETSUO

IPC: G01N27/404 ,  G01N27/416

Abstract: PURPOSE:To measure the concentration of dissolved gas with high precision without being affected by the flow speed of a sample. CONSTITUTION:A dissolved gas sensor 10 consists of a hollow, cylindrical sensor body 11, a well-gas-permeable barrier 12 fixed to the opening at the end thereof, a submersible spacer 13 arranged in the sensor body in contact with the barrier 12, an operating pole 14 arranged in the sensor body in contact with the spacer 13, an opposite pole 16 fitted in a supporting pipe 15 to support the operating pole 14, and electrolyte 17 filled in the sensor body, outside the supporting pipe 15. A pulse voltage applying means 18 applies to the operating pole 14 of the sensor 10, non-electrolysis potential for which no electrolysis occurs and electrolysis potential for which electrolysis occurs, on an alternate basis, to measure a pulse electrolytic current in dissolved gas in a sample, permeating through the barrier, to find the concentration of the dissolved gas.

公开(公告)号：JPH0387649A

公开(公告)日：1991-04-12

申请号：JP14186390

申请日：1990-05-31

Applicant: TOA ELECTRONICS

Inventor： FURUYA ETSUO

IPC: G01N27/48 ,  G01N27/404 ,  G01N27/416

Abstract: PURPOSE:To continuously measure the chlorous acid ions in a sample by adding an acid to the sample liquid to adjust its pH to the prescribed pH value or below meeting the concn. of the chloride added thereto simultaneously with the acid already dissolved in the sample or before or after such addition. CONSTITUTION:The acid is added to the sample liquid to adjust its pH to the prescribed pH value or below meeting the concn. of the chloride added thereto simultaneously with the acid already dissolved in the sample or before or after such addition, by which the chlorous acid ions contained in the sample liquid are converted to the quantitatively corresponding chlorine dioxide. The concn. of this chlorine dioxide is measured by using a diaphragm type polarograph type electrode, by which the concn. of the chlorous acid ion in the sample liquid is determined. When the concn. of the chlorus acid ions in the sample liquid contg. the chlorus acid ions and chlorine dioxide is measured, the concn. of the chlorine dioxide in the sample is first measured by using the diaphragm type polarograph type electrode and thereafter, the pH is adjusted to the prescribed pH value or below and again the concn. of the chlorine dioxide is measured by using the diaphragm type polarograph type electrode. The concn. of the chlorous acid ion in the sample is determined from the difference between the concns. of the chlorine dioxide before and after the addition.

公开(公告)号：JPH02296145A

公开(公告)日：1990-12-06

申请号：JP11628989

申请日：1989-05-10

Applicant: TOA ELECTRONICS

Inventor： FURUYA ETSUO

IPC: G01N27/49 ,  G01N27/416

Abstract: PURPOSE:To make it possible to perform measurement for a long period without special electrolyte and reagent which must be replenished and replaced by using a sample liquid itself containing chlorite ions as electrolyte, and measuring electrolysis current. CONSTITUTION:Two electrodes of working electrode 3 and a counter electrode 4 or three electrodes of the electrodes and an additional reference electrode 5 are immersed into a sample liquid 2. The electrode 3 comprising noble metal or carbon is relatively moved with respect to the sample liquid 2. Chlorite ions in the sample liquid 2 undergo electrolysis, and oxidizing current is generat ed. The voltage of the oxidizing current is applied to the electrode and the generated current is measured with an ammeter 6 with the couter electrode 4 as a reference in the case of two electrode and with a potentiostat 7 with the electrode 5 as a reference in the case of the three electrodes. Since the oxidizing current is proportional to the concentration of the dissolved chlorite ions, the concentration of the chlorite ions in the sample liquid 2 can be obtained by obtaining the relationship between the concentration of the chlorite ions and the value of the oxidizing current beforehand.

公开(公告)号：JPH02296143A

公开(公告)日：1990-12-06

申请号：JP11628889

申请日：1989-05-10

Applicant: TOA ELECTRONICS

Inventor： FURUYA ETSUO

IPC: G01N27/416

Abstract: PURPOSE:To make it possible to perform measurement continuously for a long period without special electrolyte which must be replenished and replaced by using a sample liquid itself dissoved in chlorine dioxide, and measuring electrolytic current. CONSTITUTION:Two electrodes of a working electrode 3 and a counter electrode 4 or three electrodes of said electrodes and an additional reference electrode 5 are immersed into a sample liquid 2. The electrode 3 comprising noble metal or a carbon is relatively moved with respect to the sample liquid 2. Dissolved chlorine dioxide in the sample liquid 2 undergoes electrolysis, and a reduction current is generated. Then, the voltage of the reduction current is applied to the electrode 3 with an ammeter 6 with the counter electrode 4 as a reference in the case of two electrodes and with a potentiostat 7 with the electrode 5 as a reference in the case of three electrodes. Thus, the generated current is measured, or the short-circuit current between the electrode 3 and the counter electrode 4 is measured. Since the reduction current is proportional to the concentration of the dissolved chlorine dioxide, the concentration of the dissolved chlorine dioxide can be obtained by obtaining the relationship between the concentration of the dissolved chlorine dioxde and the value of the reduction current beforehand.

公开(公告)号：JPH036450A

公开(公告)日：1991-01-11

申请号：JP14237189

申请日：1989-06-05

Applicant: TOA ELECTRONICS

Inventor： OIKAWA KIKUO ,  FURUYA ETSUO

IPC: G01N27/416

Abstract: PURPOSE:To suppress the reduction of a liquid electrolyte and to prevent the contamination of a cathode by forming an anode from silver or silver/silver chloride while forming the cathode from gold or carbon and providing the third electrode composed of a noble metal or carbon to the periphery of the cathode. CONSTITUTION:A diaphragm 2 composed of polytetrafluoroethylene having a film thickness of 3 - 20mum is provided to one end of a cylindrical support 1 and a liquid electrolyte 3 composed of an acidic aqueous potassium chloride solution is received in the support 1 and a columnar insulator 6 is fixed to the support 1. An anode 4 is fixed to the outer periphery of the insulator 6 and a cathode 5 is fixed to the lower end thereof and one flat surface of the cathode 5 is arranged in contact with the diaphragm 2. The third annular electrode 7 provide din a concentric circular shape with respect to the cathode 5 is fixed to the periphery of the cathode 5 so that one flat surface thereof is arranged to the lower end of the insulator 6 in contact with the diaphragm 2. Voltages same or different are respectively applied to the cathode 5 and the electrode 7 from respective power supplies within a range generating a ClO2 reducing current and the ClO2 reducing current flowing between the anode 4 and the cathode 5 and transmitting through the diaphragm 2 is measured by an ammeter. The reducing current wherein the applied voltages are stable within a range of about 0 - 500mV can be obtained.

公开(公告)号：JPH02296146A

公开(公告)日：1990-12-06

申请号：JP11629089

申请日：1989-05-10

Applicant: TOA ELECTRONICS

Inventor： FURUYA ETSUO

IPC: G01N27/49 ,  G01N27/416

Abstract: PURPOSE:To make it possible to perform measurement for both chlorine dioxide and chlorite ion at the same time continuously when the chlorine dioxide and the chlorite ions are present together by using a sample liquid itself as a electrolyte, applying two different kinds of voltages, and measuring an electrolysis currents. CONSTITUTION:Two working electrodes 3 and one or two counter electrodes 4 or one or two additional reference electrodes 5 are immersed in a sample liquid 2. The electrodes 3 comprising noble metal or carbon are relatively moved with respect to the sample liquid 2. With the electrodes 5 as references, or with the counter electrodes 4 as references when the electrodes 5 are not pro vided, the different voltages are applied to the electrodes 3, respectively. The voltage which generates the reduction current of the chlorine dioxide is applied or not to one electrode, and the voltage which generates the oxidizing current for the chlorite ions is applied to the other electrode. Then, the generated currents are measured with ammeters 6 or potentiometer potentiostats 7, and the concentrations of the chlorine dioxide and the chlorite ions can be obtained.