Electrochemical gas sensor system

Patent metadata

Field	Value
Publication number	US-9726633-B2
Application number	US-201514734402-A
Country	US
Kind code	B2
Filing date	Jun 9, 2015
Priority date	Jun 21, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

An electrochemical gas sensor system ( 100 ) detects the concentration of a harmful gas in a measuring environment ( 70 ). The electrochemical gas sensor system ( 100 ) contains a voltage generator ( 19 ) and an electrochemical gas sensor ( 1 ). The electrochemical gas sensor ( 1 ) has a sensor housing ( 2 ) and a gas inlet ( 18 ). A measuring electrode ( 3 ), an auxiliary electrode ( 5 ), a reference electrode ( 17 ), a first generator electrode ( 13 ) and a second generator electrode ( 14 ) are in an electrolyte liquid ( 11 ) in the sensor housing ( 2 ). A salt ( 28 ) (halide) of a halogen is dissolved in the electrolyte liquid ( 11 ). The first generator electrode ( 13 ) and the second generator electrode ( 14 ) are connected to the voltage generator ( 19 ) to form a galvanic source. The galvanic source causes the salt ( 28 ) (halide) to react to form a halogen ( 28 ′). A defined, largely stable reference voltage potential becomes established on the reference electrode ( 17 ).

First claim

What is claimed is:

1. An electrochemical gas sensor system for detecting the concentration of a gas in a measuring environment, the electrochemical gas sensor system comprising:
a voltage generator;
an electrochemical gas sensor comprising:
a sensor housing with a gas inlet permitting a gas to enter the electrochemical gas sensor from the measuring environment;
an electrolyte liquid in the sensor housing;
an electrode configuration arranged in the sensor housing, the electrode configuration comprising a measuring electrode, an auxiliary electrode, a reference electrode and a first generator electrode and a second generator electrode, wherein:
the reference electrode is arranged between the first generator electrode and the second generator electrode;
the first generator electrode is electrically connected to a first terminal of the voltage generator and the second generator electrode is electrically connected to a second terminal of the voltage generator; and
the voltage generator, the first generator electrode and the second generator electrode form a galvanic cell with the electrolyte liquid.

2. An electrochemical gas sensor system in accordance with claim 1 , wherein at least a halide compound or a halide is contained in the electrolyte liquid.

3. An electrochemical gas sensor system in accordance with claim 2 , wherein:
the halide compound contained in the electrolyte liquid or the halide contained in the electrolyte liquid is reacted by means of the galvanic cell to form a halogen; and
a defined reference potential becomes established on the reference electrode.

4. An electrochemical gas sensor system in accordance with claim 2 , wherein:
the halide compound contained in the electrolyte liquid or the halide contained in the electrolyte liquid is bromide, and reacts to form bromine by means of the galvanic cell; and
a defined, reference potential in the range of 935 mV±25 mV becomes established on the reference electrode.

5. An electrochemical gas sensor system in accordance with claim 1 , wherein the voltage generator comprises at least one of a settable voltage generator, a settable voltage source and a settable power source.

6. An electrochemical gas sensor system in accordance with claim 1 , wherein the voltage generator comprises a battery.

7. An electrochemical gas sensor system in accordance with claim 1 , wherein a nonwoven, permeable to the electrolyte liquid, is arranged at the first generator electrode and a nonwoven, permeable to the electrolyte liquid, is arranged at the second generator electrode.

8. An electrochemical gas sensor system in accordance with claim 7 , wherein the nonwovens, permeable to the electrolyte liquid and arranged each at the first generator electrode and at the second generator electrode, set an installed position with predetermined distances of the generator electrodes from the reference electrode and a predetermined distance between the generator electrodes.

9. An electrochemical gas sensor system in accordance with claim 8 , wherein the first and second generator electrodes and the reference electrode and the nonwovens permeable to the electrolyte liquid are enclosed by an inner housing that is not permeable to the electrolyte liquid.

10. An electrochemical gas sensor system in accordance with claim 9 , wherein at least one of the nonwovens, permeable to the electrolyte liquid, transports the electrolyte liquid from the sensor housing to an area between the first and second generator electrodes into the inner housing impermeable to the electrolyte liquid towards the first and second generator electrodes.

11. An electrochemical gas sensor system comprising:
a sensor housing with a gas inlet;
an electrolyte liquid in the sensor housing;
a measuring electrode;
an auxiliary electrode;
a reference electrode;
a voltage generator;
an analyzing unit comprising a potentiostat connected to the measuring electrode, connected to the auxiliary electrode and connected to the reference electrode to set or regulate a potential on the measuring electrode and the auxiliary electrode with respect to a reference potential on the reference electrode; and
an electric circuit, in which an electric current becomes established, the electric circuit comprising a first generator electrode electrically connected to a first terminal of the voltage generator, a second generator electrode electrically connected to a second terminal of the voltage generator, and applying a voltage between the first generator electrode and the second generator electrode to form an electric field between the first generator electrode and the second generator electrode, wherein the reference electrode is arranged between the first generator electrode and the second generator electrode whereby, due to the electric field upon the electric current becoming established, a defined reference potential becomes established on the reference electrode arranged between the first generator electrode and the second generator electrode.

12. An electrochemical gas sensor system in accordance with claim 11 , wherein at least one of a halide compound or a halide is contained in the electrolyte liquid.

13. An electrochemical gas sensor system in accordance with claim 12 , wherein:
the halide compound contained in the electrolyte liquid or the halide contained in the electrolyte liquid is reacted by means of the electric circuit to form a halogen; and
the defined reference potential established on the reference electrode is in a range of 935 mV+25 mV.

14. An electrochemical gas sensor system in accordance with claim 12 , wherein:
the halide compound contained in the electrolyte liquid or the halide contained in the electrolyte liquid is bromide, and reacts to form bromine by means of the electric circuit; and
the defined reference potential established on the reference electrode is in a range of 935 mV±25 mV.

15. An electrochemical gas sensor system in accordance with claim 11 , wherein the voltage generator comprises at least one of a settable voltage generator, a settable voltage source and a settable power source.

16. An electrochemical gas sensor system in accordance with claim 11 , wherein the voltage generator comprises a battery.

17. An electrochemical gas sensor system in accordance with claim 11 , further comprising:
a nonwoven permeable to the electrolyte liquid arranged at the first generator electrode and
a nonwoven permeable to the electrolyte liquid is arranged at the second generator electrode.

18. An electrochemical gas sensor system in accordance with claim 17 , wherein the nonwoven permeable to the electrolyte liquid arranged each at the first generator electrode and at the second generator electrode set an installed position with predetermined distance of the first generator electrodes from the reference electrode, predetermined distance of the second generator electrodes from the reference electrode and a predetermined distance between the first generator electrode and the second generator electrode.

19. An electrochemical gas sensor system in accordance with claim 18 , wherein the first generator electrode and the second generator electrode and the reference electrode and the nonwovens permeable to the electrolyte liquid are enclosed by an inner housing that is not permeable to the electrolyte liquid.

20. An electrochemical gas sensor system in accordance with claim 19 , wherein at least one of the nonwovens, permeable to the electrolyte liquid, transports the electrolyte liquid from the s

Assignees

• Draeger Safety Ag & Co Kgaa

Inventors

• Mett Frank
• Lichtenfeldt Kerstin
• Jörn Johanna

Classifications

• G01N27/404 Primary

  Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid {, e.g. Clark-type oxygen sensors} · CPC title

• G01N27/49

  Systems involving the determination of the current at a single specific value, or small range of values, of applied voltage for producing selective measurement of one or more particular ionic species · CPC title

• G01N27/413 Primary

  Concentration cells using liquid electrolytes {measuring currents or voltages in voltaic cells} · CPC title