CA2019728C - Safe failure ion selective combination electrode - Google Patents
Safe failure ion selective combination electrodeInfo
- Publication number
- CA2019728C CA2019728C CA002019728A CA2019728A CA2019728C CA 2019728 C CA2019728 C CA 2019728C CA 002019728 A CA002019728 A CA 002019728A CA 2019728 A CA2019728 A CA 2019728A CA 2019728 C CA2019728 C CA 2019728C
- Authority
- CA
- Canada
- Prior art keywords
- electrode
- range
- predetermined safe
- electrical
- electrical output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000243 solution Substances 0.000 claims description 24
- 239000012085 test solution Substances 0.000 claims description 12
- 238000012544 monitoring process Methods 0.000 claims description 6
- 230000007257 malfunction Effects 0.000 claims description 2
- 150000002500 ions Chemical class 0.000 description 28
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 229910021607 Silver chloride Inorganic materials 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- XNGIFLGASWRNHJ-UHFFFAOYSA-L phthalate(2-) Chemical compound [O-]C(=O)C1=CC=CC=C1C([O-])=O XNGIFLGASWRNHJ-UHFFFAOYSA-L 0.000 description 2
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/4163—Systems checking the operation of, or calibrating, the measuring apparatus
- G01N27/4165—Systems checking the operation of, or calibrating, the measuring apparatus for pH meters
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Pathology (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Molecular Biology (AREA)
- Immunology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Emergency Alarm Devices (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Investigating Or Analysing Materials By The Use Of Chemical Reactions (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
A safe failure ion selective combination electrode in which a signal unit provides a signal if combination electrode output falls outside a predetermined range.
Description
SAFE FAILURE ION SELECTIVE COHBINATION ELECTRODE
Field of the Invention This invention relates to ion selective combination electrodes, and more particularly, to such devices which can detect and signal their own breakdown.
Backqround of the Invention General purpose pH combination electrodes that operate over the full pH range and provide an output of about minus 60 millivolts (mV) per unit of pH, output at pH 7.0 being zero mV are known. It is known also to shift the zero mV point, as to pH 4.0 or 10.0, to avoid automatic temperature compensating metering circuits, by varying internal solution formulation.
Summarv of the Invention It has been discovered that an ion selective combination electrode in which zero mV output corresponds to ion concentrations, such as pH, outside a desired range makes it possible to detect an electrode's internal breakdown.
According to one aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration range comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a first element in said inner solution, and a first electrical line for making an external electrical connection to said fir~t element, ~. ' ~k' 231 q~
la 7442~-36 a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, said un$t being constructed to provide a warning signal if said electrical output is outside said predetermined safe electrical output range, wherein said electrode subsystem has a predetermined safe electrical output range that is a voltage range that does not include zero volt, and said electrical output is zero volt when said electrode subsystem malfunctions, and wherein said inner solution is selected to provide said voltage range that does not include zero volt.
According to another aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration range . ~'.
.
lb 2 0 1 9 7 2 8 74424-36 comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a fir~t element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, ~aid unit being constructed to provide a warning signal if said electrical output is outæide said predetermined safe electrical output range, wherein said system monitors pH, and wherein said predetermined safe ion concentration range includes a pH value of 7.0, and said inner solution has a pH that ~, 1 j ~ ~
lc 74424-36 is outside of said predetermined ~afe ion concentration range.
According to another aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe pH range that includes a pH of 7 compri~ing an ion selective electrode, said electrode including a ve sse 1 , an inner solution in said vessel that has a pH outside of said predetermined safe pH range;
a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an output voltage that varies as a function of pH of said test solution, said output voltage having a predetermined safe output voltage range associated with said predetermined safe pH range, said predetermined safe output voltage range not including zero volt, said output voltage being zero when said vessel ruptures, and a control unit electrically connected to said first and second lines to receive said output voltage, said unit being constructed to provide a warning signal if said output voltage is outside said predetermined safe output ld 2 0 1 9 7 2 8 74424-36 voltage range.
Preferred ~bodiment The preferred embodiment is shown in the attached drawing, the structure and operation of which iB then described.
Drawing In the drawing is shown a diagrammatic view of said preferred embodiment.
Structure The preferred embodiment is indicated generally at 10 in the drawing.
The ion selective combination electrode 10 has as two functional parts an ion selective electrode indicated generally at 12 and a reference electrode indicated generally at 14.
Ion selective electrode 12 has a glass stem 16 in communication with ion selective glass bulb 18. Within the vessel defined by stem 16 and bulb 18 is solution 20, in which hang silver wire 22 with dependent therefrom silver chloride billet 24.
Inner solution 20 is a pH 5.0 solution prepared by adding Potassium Acide Phthalate (Merck, AR Primary StandARd), 0.05 mols phthalate, to 1.8 mols of potassium chloride, the whole made up to a one liter quantity with deionized water, and adjusted to its final pH with NaOH. Seal 26 provides a seal around tubular portion 16 and wire 22.
Bushing 28, which has liquid junction 30 extending therethrough, is an annulus which positions electrode 12 within electrode 14. The latter contains, above bushing 28, a standard prior art reference electrolyte solution 32. Silver wire 34 extends into solution 32, and has dependent from it silver chloride billet 36. Seal 38, which is annular, seals wire 34 and both electrodes therearound.
Container 40 is shown with, within it, a solution 42 the pH of which is being monitored.
Field of the Invention This invention relates to ion selective combination electrodes, and more particularly, to such devices which can detect and signal their own breakdown.
Backqround of the Invention General purpose pH combination electrodes that operate over the full pH range and provide an output of about minus 60 millivolts (mV) per unit of pH, output at pH 7.0 being zero mV are known. It is known also to shift the zero mV point, as to pH 4.0 or 10.0, to avoid automatic temperature compensating metering circuits, by varying internal solution formulation.
Summarv of the Invention It has been discovered that an ion selective combination electrode in which zero mV output corresponds to ion concentrations, such as pH, outside a desired range makes it possible to detect an electrode's internal breakdown.
According to one aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration range comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a first element in said inner solution, and a first electrical line for making an external electrical connection to said fir~t element, ~. ' ~k' 231 q~
la 7442~-36 a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, said un$t being constructed to provide a warning signal if said electrical output is outside said predetermined safe electrical output range, wherein said electrode subsystem has a predetermined safe electrical output range that is a voltage range that does not include zero volt, and said electrical output is zero volt when said electrode subsystem malfunctions, and wherein said inner solution is selected to provide said voltage range that does not include zero volt.
According to another aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration range . ~'.
.
lb 2 0 1 9 7 2 8 74424-36 comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a fir~t element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, ~aid unit being constructed to provide a warning signal if said electrical output is outæide said predetermined safe electrical output range, wherein said system monitors pH, and wherein said predetermined safe ion concentration range includes a pH value of 7.0, and said inner solution has a pH that ~, 1 j ~ ~
lc 74424-36 is outside of said predetermined ~afe ion concentration range.
According to another aspect of the invention there is provided an ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe pH range that includes a pH of 7 compri~ing an ion selective electrode, said electrode including a ve sse 1 , an inner solution in said vessel that has a pH outside of said predetermined safe pH range;
a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an output voltage that varies as a function of pH of said test solution, said output voltage having a predetermined safe output voltage range associated with said predetermined safe pH range, said predetermined safe output voltage range not including zero volt, said output voltage being zero when said vessel ruptures, and a control unit electrically connected to said first and second lines to receive said output voltage, said unit being constructed to provide a warning signal if said output voltage is outside said predetermined safe output ld 2 0 1 9 7 2 8 74424-36 voltage range.
Preferred ~bodiment The preferred embodiment is shown in the attached drawing, the structure and operation of which iB then described.
Drawing In the drawing is shown a diagrammatic view of said preferred embodiment.
Structure The preferred embodiment is indicated generally at 10 in the drawing.
The ion selective combination electrode 10 has as two functional parts an ion selective electrode indicated generally at 12 and a reference electrode indicated generally at 14.
Ion selective electrode 12 has a glass stem 16 in communication with ion selective glass bulb 18. Within the vessel defined by stem 16 and bulb 18 is solution 20, in which hang silver wire 22 with dependent therefrom silver chloride billet 24.
Inner solution 20 is a pH 5.0 solution prepared by adding Potassium Acide Phthalate (Merck, AR Primary StandARd), 0.05 mols phthalate, to 1.8 mols of potassium chloride, the whole made up to a one liter quantity with deionized water, and adjusted to its final pH with NaOH. Seal 26 provides a seal around tubular portion 16 and wire 22.
Bushing 28, which has liquid junction 30 extending therethrough, is an annulus which positions electrode 12 within electrode 14. The latter contains, above bushing 28, a standard prior art reference electrolyte solution 32. Silver wire 34 extends into solution 32, and has dependent from it silver chloride billet 36. Seal 38, which is annular, seals wire 34 and both electrodes therearound.
Container 40 is shown with, within it, a solution 42 the pH of which is being monitored.
Wires 22 and 34 are connected with amplifier 44, which provides a voltage output reflecting the input from the two wires. The unit indicated diagrammatically and generally at 46 has control and alarm circuits and provides a warning signal if voltage goes to zero; the unit 46 is programmed so that predetermined desired voltages are in the pH range of 6.5 to 8.2, while zero voltage is at pH 5.5.
Outer wall 48 provides both the wall for reference electrode 14 and a zone 50 whereat solution being tested can be in contact with bulb 18 and junction 30, for sealed electrical contact therethrough (through holes not shown).
The following chart compares the preferred embodiment and prior art above referred to:
pH of a solution 4.0 5.06.0 7.0 8.0 9.0 being tested Preferred Example ~ >
safety range (6 5) (8 2) Preferred Example <~ .
low pH alarm range . . -~>
Preferred Example high pH alarm range .
Prior Art electrode 180 120 60 : 0 -60 : -120 mV output l PriGr Art electrode : x failure point (pH 7.0) Preferred Example 90 30 0 -30 : -90 -150 : -210 electrode mV output ¦ .
Preferred Example x :
electrode failure (pH 5.5) Operation In normal use, with the combination electrode 10 in the _ 69204-185 test liquid 42, pH is within the safe range set into unit 46, and is therein monitored. If tube 16 ruptures, voltage goes to zero, which in the invention is outside the safe or predetermined operating range, and a signal circuit in unit 46 gives its signal.
The signal is also given at other voltages outside the predeterminedly desired range.
Other embodiments within the following claims will appear to those skilled in the art.
Outer wall 48 provides both the wall for reference electrode 14 and a zone 50 whereat solution being tested can be in contact with bulb 18 and junction 30, for sealed electrical contact therethrough (through holes not shown).
The following chart compares the preferred embodiment and prior art above referred to:
pH of a solution 4.0 5.06.0 7.0 8.0 9.0 being tested Preferred Example ~ >
safety range (6 5) (8 2) Preferred Example <~ .
low pH alarm range . . -~>
Preferred Example high pH alarm range .
Prior Art electrode 180 120 60 : 0 -60 : -120 mV output l PriGr Art electrode : x failure point (pH 7.0) Preferred Example 90 30 0 -30 : -90 -150 : -210 electrode mV output ¦ .
Preferred Example x :
electrode failure (pH 5.5) Operation In normal use, with the combination electrode 10 in the _ 69204-185 test liquid 42, pH is within the safe range set into unit 46, and is therein monitored. If tube 16 ruptures, voltage goes to zero, which in the invention is outside the safe or predetermined operating range, and a signal circuit in unit 46 gives its signal.
The signal is also given at other voltages outside the predeterminedly desired range.
Other embodiments within the following claims will appear to those skilled in the art.
Claims (3)
1. An ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration ranqe comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, said unit being constructed to provide a warning signal if said electrical output is outside said predetermined safe electrical output range, wherein said electrode subsystem has a predetermined safe electrical output range that is a voltage range that does not include zero volt, and said electrical output is zero volt when said electrode subsystem malfunctions, and wherein said inner solution is selected to provide said voltage range that does not include zero volt.
2. An ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe ion concentration range comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel, a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an electrical output that varies as a function of ion concentration of said test solution, said electrical output having a predetermined safe electrical output range associated with said predetermined safe ion concentration range, said electrical output being outside said predetermined safe electrical output range when said electrode subsystem is malfunctioning, and a control unit electrically connected to said first and second lines to receive said electrical output, said unit being constructed to provide a warning signal if said electrical output is outside said predetermined safe electrical output range, wherein said system monitors pH, and wherein said predetermined safe ion concentration range includes a pH value of 7.0, and said inner solution has a pH that is outside of said predetermined safe ion concentration range.
3. An ion selective combination electrode system for monitoring ion concentration of a test solution for which there is an associated predetermined safe pH range that includes a pH of 7 comprising an ion selective electrode, said electrode including a vessel, an inner solution in said vessel that has a pH outside of said predetermined safe pH range;
a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an output voltage that varies as a function of pH of said test solution, said output voltage having a predetermined safe output voltage range associated with said predetermined safe pH range, said predetermined safe output voltage range not including zero volt, said output voltage being zero when said vessel ruptures, and a control unit electrically connected to said first and second lines to receive said output voltage, said unit being constructed to provide a warning signal if said output voltage is outside said predetermined safe output voltage range.
a first element in said inner solution, and a first electrical line for making an external electrical connection to said first element, a reference electrode including a second element and a second electrical line for making an external electrical connection to said second element, said ion selective electrode and said reference electrode being in an electrode subsystem providing an output voltage that varies as a function of pH of said test solution, said output voltage having a predetermined safe output voltage range associated with said predetermined safe pH range, said predetermined safe output voltage range not including zero volt, said output voltage being zero when said vessel ruptures, and a control unit electrically connected to said first and second lines to receive said output voltage, said unit being constructed to provide a warning signal if said output voltage is outside said predetermined safe output voltage range.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37788789A | 1989-07-10 | 1989-07-10 | |
| US377,887 | 1989-07-10 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2019728A1 CA2019728A1 (en) | 1991-01-10 |
| CA2019728C true CA2019728C (en) | 1995-01-17 |
Family
ID=23490917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002019728A Expired - Fee Related CA2019728C (en) | 1989-07-10 | 1990-06-25 | Safe failure ion selective combination electrode |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPH0346554A (en) |
| CA (1) | CA2019728C (en) |
| DE (1) | DE4021853C2 (en) |
| FR (1) | FR2649486A1 (en) |
| GB (1) | GB2233768B (en) |
| IT (1) | IT1240484B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6148196B2 (en) | 2014-03-31 | 2017-06-14 | 株式会社クボタ | Working machine hydraulic system |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4331198Y1 (en) * | 1965-03-04 | 1968-12-18 | ||
| JPS4838890B1 (en) * | 1968-12-16 | 1973-11-20 | ||
| GB1337544A (en) * | 1969-12-19 | 1973-11-14 | Ple Sey Co Ltd | Fluid testing apparatus |
| US3661748A (en) * | 1970-04-07 | 1972-05-09 | Instrumentation Labor Inc | Fault sensing instrumentation |
| GB1368823A (en) * | 1972-05-10 | 1974-10-02 | Activion Glass Ltd | Ion-responsive electrodes |
| DE2706942A1 (en) * | 1976-03-17 | 1977-09-29 | Owens Illinois Inc | COMBINATION ELECTRODE |
| US4039933A (en) * | 1976-03-25 | 1977-08-02 | Instrumentation Laboratory, Inc. | Continuous calibration system and method for analytical instruments |
| US4189367A (en) * | 1978-10-19 | 1980-02-19 | Leeds & Northrup Company | Method for testing ion selective electrodes in continuous measuring systems |
| JPS58178410A (en) * | 1982-04-14 | 1983-10-19 | Fuji Electric Co Ltd | Warning circuit |
| DE3516018A1 (en) * | 1985-05-02 | 1986-12-18 | Holger 1000 Berlin Kruse | PORTABLE DEVICE FOR DETERMINING THE STOMACH FUNCTION ON THE BASIS OF THE ACIDIC ACID |
| US4822456A (en) * | 1987-06-05 | 1989-04-18 | Bryan Avron I | Ion measuring apparatus and monitoring system |
| US4900422A (en) * | 1988-07-05 | 1990-02-13 | Bryan Avron I | System for monitoring and reporting the operability and calibration status of a dissolved oxygen sensor |
-
1990
- 1990-06-25 CA CA002019728A patent/CA2019728C/en not_active Expired - Fee Related
- 1990-06-28 JP JP2171284A patent/JPH0346554A/en active Pending
- 1990-07-09 DE DE4021853A patent/DE4021853C2/en not_active Expired - Fee Related
- 1990-07-09 IT IT67507A patent/IT1240484B/en active IP Right Grant
- 1990-07-10 FR FR9008768A patent/FR2649486A1/en not_active Withdrawn
- 1990-07-10 GB GB9015209A patent/GB2233768B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| IT9067507A0 (en) | 1990-07-09 |
| FR2649486A1 (en) | 1991-01-11 |
| IT1240484B (en) | 1993-12-17 |
| DE4021853A1 (en) | 1991-01-24 |
| JPH0346554A (en) | 1991-02-27 |
| GB9015209D0 (en) | 1990-08-29 |
| DE4021853C2 (en) | 1995-03-09 |
| CA2019728A1 (en) | 1991-01-10 |
| IT9067507A1 (en) | 1992-01-09 |
| GB2233768B (en) | 1994-01-05 |
| GB2233768A (en) | 1991-01-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |