Method and device for detecting the composition of gas mixtures

• US 8,256,264 B2
• Filed: 11/26/2008
• Issued: 09/04/2012
• Est. Priority Date: 11/29/2007
• Status: Active Grant

• Current Assignee: Sacmi Cooperativa Meccanici Imola Soc. Coop.
• Original Assignee: Sacmi Cooperativa Meccanici Imola Soc. Coop.
• Inventors: Bosi, Gildo, Remondini, Marco, Ricco', Ibanez
• Primary Examiner(s): Raevis, Robert R
• Application Number:
  US12/675,338
• Publication Number:
  US 20100300180A1
• Time in Patent Office: 1,378 Days
• Field of Search: None
• US Class Current: 73/1.06
• CPC Class Codes: G01N 33/0006 Calibrating gas analysers
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array electrochemical electrode arrays G01N27/27

Abstract

A method for detecting the composition of an unknown gas mixture (M_inc) through an electronic nose (2) equipped with a measuring chamber (3) that houses at least one sensor comprises the steps of: calibrating a sensor by feeding a known gas mixture (M_n) into the measuring chamber (3); feeding the unknown gas mixture (M_inc) into the chamber (3), while keeping the unknown gas mixture (Mine) in a predetermined desired state; and detecting the composition of the unknown gas mixture (M_inc) by means of the sensor.

Claims

1. A method for detecting the composition of an unknown gas mixture (M_inc) through an electronic nose (2) equipped with a measuring chamber (3) that houses at least one sensor, comprising the steps of:

calibrating the at least one sensor by feeding a known gas mixture (M_n) into the measuring chamber (3);

feeding the unknown gas mixture (M_inc) into the chamber (3), while keeping the unknown gas mixture (M_inc) in a predetermined desired state;

detecting the composition of the unknown gas mixture (M_inc) by means of the at least one sensor,

wherein the method further comprises steps of

mixing the unknown gas mixture (M_inc) with a cleaning gas mixture (M_p) to form a sample gas mixture (M_camp) and

regulating the state of the cleaning gas mixture (M_p) in order to keep the sample gas mixture (M_camp) and hence the unknown gas mixture (M_inc) in the predetermined desired state, in such a way as to keep the humidity of the sample gas mixture M_camp, and hence of the unknown gas mixture M_incconstant, and

wherein the method further comprises a step of making the cleaning gas mixture (M_p) flow through a catalyser (16) before mixing the cleaning gas mixture (M_p)with the unknown gas mixture (M_inc).

2. The method according to claim 1, further comprising the steps of measuring the humidity and temperature of the sample gas mixture M_camp via a humidity and temperature sensor (8) before the sample gas mixture M_camp enters the measuring chamber (3) and varying the humidity of the cleaning gas mixture M_p via a conditioning system (18) in such a way as to keep the humidity of the sample gas mixture M_camp and hence of the unknown gas mixture M_incconstant.

3. The method according to claim 1, wherein the step of calibrating the at least one sensor by feeding a known gas mixture (M_n) into the chamber (3) comprises the further step of keeping the known gas mixture (M_n) in the predetermined desired state.

4. The method according to claim 1, wherein the method further comprises the step of mixing a fraction of a standard gas (G_s) and a fraction of the cleaning gas mixture (M_p) to form the known gas mixture (M_n).

5. The method according to claim 4, wherein the step of calibrating the at least one sensor comprises a step of regulating the state of the cleaning gas mixture (M_p) in such a way as to keep the known gas mixture (M_n) in the desired state.

6. The method according to claim 1, wherein the state of the cleaning gas mixture (M_p) is regulated by a conditioning system (18).

7. The method according to claim 1, wherein the step of regulating the state of the cleaning gas mixture (M_p) comprises a step of delivering the cleaning gas mixture (M_p) into an evaporating chamber (28) on the bottom of which there is water heated by a heater (32, 33), the water evaporating and thus increasing the degree of humidity of the cleaning gas mixture (M_p).

8. The method according to claim 7, wherein the step of regulating the state of the cleaning gas mixture (M_p) comprises a step of delivering the cleaning gas mixture (M_p) leaving the evaporating chamber (28) into a condenser device (30) in such a way as to lower the degree of humidity of the cleaning gas mixture (M_p) to a preset value.

9. The method according to claim 1, wherein the method comprises a step of making the cleaning gas mixture (M_p) flow through a catalyser (16) before mixing the cleaning gas mixture (M_p) with a standard gas (G_s) to form the known gas mixture (M_n).

10. The method according to claim 1, wherein the method comprises a step of making the cleaning gas mixture (M_p) flow through an active carbon filter (17) before mixing the cleaning gas mixture (M_p) with the unknown gas mixture (M_inc) and with a standard gas (G_s).

11. The method according to claim 1, wherein the step of detecting the composition of the unknown gas mixture (M_inc) comprises a step of detecting an odoriferous compound in the unknown gas mixture (M_inc).

12. The method according to claim 1, where the unknown gas mixture (M_inc) is sample air (A_c) with unknown odour and the known gas mixture (M_n) is reference air (A_r), characterized in that the method comprises steps of:

calibrating the sensor with the reference air (A_r);

delivering a fraction of the sample air (A_c) into the chamber (3);

detecting the unknown odour in the sample air (A_c);

regulating the state of one of either the reference air (A_r) or the sample air (A_c) before both the sample air (A_c) and the reference air (A_r) flow into the chamber (3).

13. The method according to claim 12, wherein during the regulating step the state of the reference air (A_r) is regulated.

14. The method according to claim 13, wherein the step of regulating the state of the reference air (A_r) comprises a step of regulating the temperature and humidity of the reference air (A_r).

15. The method according to claim 13, wherein the step of regulating the state of the reference air (A_r) comprises a step of delivering the reference air (A_r) into an evaporating chamber (28) on the bottom of which there is water heated by a heater (32, 33), the water evaporating and thus increasing the degree of humidity of the reference air (A_r).

16. The method according to claim 15, wherein the step of regulating the reference air (A_r) comprises a step of delivering the reference air (A_r) leaving the evaporating chamber (28) into a condenser device (30) in such a way as to lower the degree of humidity of the reference air (A_r) to a preset value.

17. The method according to claim 16, wherein the method comprises a step of measuring the temperature and percentage of humidity of the sample air (A_c) before the sample air (A_c) flows into the measuring chamber (3).

18. The method according to claim 17, wherein the step of regulating the state of the reference air (A_r) is a function of the step of measuring the temperature and percentage of humidity of the sample air (A_c).

19. The method according to claim 17, comprising a step of regulating the degree of condensation of the reference air (A_r) inside the condenser device (30), wherein the step of regulating the degree of condensation of the reference air (A_r) inside the condenser device (30) is a function of the measured temperature and relative humidity of the sample air (A_c) so that the absolute humidity of the reference air (A_r) is substantially the same as the absolute humidity of the sample air (A_c).

20. The method according to claim 12, characterized in that the method comprises a step of making the temperature of the reference air (A_r) and that of the sample air (A_c) equal before the two types of air flow into the measuring chamber (3).

21. A method for detecting the composition of an unknown gas mixture (M_inc) through an electronic nose (2) equipped with a measuring chamber (3) that houses at least one sensor, comprising the steps of:

calibrating the at least one sensor by feeding a known gas mixture (M_n) into the measuring chamber (3);

feeding the unknown gas mixture (M_inc) into the chamber (3), while keeping the unknown gas mixture (M_inc) in a predetermined desired state;

detecting the composition of the unknown gas mixture (M_inc) by means of the at least one sensor,

wherein the method further comprises steps of;

mixing the unknown gas mixture (M_inc) with a cleaning gas mixture (M_p) to form a sample gas mixture (M_camp) and

regulating the state of the cleaning gas mixture (M_p) in order to keep the sample gas mixture (M_camp) and hence the unknown gas mixture (M_inc) in the predetermined desired state, in such a way as to keep the humidity of the sample gas mixture M_camp, and hence of the unknown gas mixture M_inc, constant, and

wherein the unknown gas mixture (M_inc) is sample air (A_c) with unknown odour and the known gas mixture (M_n) is reference air (A_r), characterized in that the method comprises steps of;

calibrating the sensor with the reference air (A_r);

delivering a fraction of the sample air (A_c) into the chamber (3);

detecting the unknown odour in the sample air (A_c);

regulating the state of one of either the reference air (A_r) or the sample air (A_c) before both the sample air (A_c) and the reference air (A_r) flow into the chamber (3), and wherein during the regulating step the state of the reference air (A_r) is regulated, and wherein the step of regulating the state of the reference air (A_r) comprises a step of regulating the temperature and humidity of the reference air (A_r).

22. A method for detecting the composition of an unknown gas mixture (M_inc) through an electronic nose (2) equipped with a measuring chamber (3) that houses at least one sensor, comprising the steps of:

calibrating the at least one sensor by feeding a known gas mixture (M_n) into the measuring chamber (3);

feeding the unknown gas mixture (M_inc) into the chamber (3), while keeping the unknown gas mixture (M_inc) in a predetermined desired state;

detecting the composition of the unknown gas mixture (M_inc) by means of the at least one sensor,

wherein the method further comprises steps of;

mixing the unknown gas mixture (M_inc) with a cleaning gas mixture (M_p) to form a sample gas mixture (M_camp) and

regulating the state of the cleaning gas mixture (M_p) in order to keep the sample gas mixture (M_camp) and hence the unknown gas mixture (M_inc) in the predetermined desired state, in such a way as to keep the humidity of the sample gas mixture M_camp, and hence of the unknown gas mixture M_incconstant, and

wherein the unknown gas mixture (M_inc)is sample air (A_c) with unknown odour and the known gas mixture (M_n) is reference air (A_r), characterized in that the method comprises steps of;

calibrating the sensor with the reference air (A_r);

delivering a fraction of the sample air (A_c) into the chamber (3);

detecting the unknown odour in the sample air (A_c);

regulating the state of one of either the reference air (A_r) or the sample air (A_c) before both the sample air (A_c) and the reference air (A_r) flow into the chamber (3), and wherein during the regulating step the state of the reference air (A_r) is regulated, and

wherein the step of regulating the state of the reference air (A_r) comprises a step of delivering the reference air (A_r) into an evaporating chamber (28) on the bottom of which there is water heated by a heater (32, 33), the water evaporating and thus increasing the degree of humidity of the reference air (A_r), and wherein the step of regulating the reference air (A_r) comprises a step of delivering the reference air (A_r) leaving the evaporating chamber (28) into a condenser device (30) in such a way as to lower the degree of humidity of the reference air (A_r) to a preset value, and wherein the method comprises a step of measuring the temperature and percentage of humidity of the sample air (A_c) before the sample air (A_c) flows into the measuring chamber (3).

23. The method of claim 22, wherein the step of regulating the state of the reference air (A_r) is a function of the step of measuring the temperature and percentage of humidity of the sample air (A_c).

24. The method of claim 22, comprising a step of regulating the degree of condensation of the reference air (A_r) inside the condenser device (30), wherein the step of regulating the degree of condensation of the reference air (A_r) inside the condenser device (30) is a function of the measured temperature and relative humidity of the sample air (A_c) so that the absolute humidity of the reference air (A_r) is substantially the same as the absolute humidity of the sample air (A_c).

25. A method for detecting the composition of an unknown gas mixture (M_inc) through an electronic nose (2) equipped with a measuring chamber (3) that houses at least one sensor, comprising the steps of:

calibrating the at least one sensor by feeding a known gas mixture (M_n) into the measuring chamber (3);

feeding the unknown gas mixture (M_inc) into the chamber (3), while keeping the unknown gas mixture (M_inc) in a predetermined desired state;

detecting the composition of the unknown gas mixture (M_inc) by means of the at least one sensor,

wherein the method further comprises steps of

mixing the unknown gas mixture (M_inc) with a cleaning gas mixture (M_p) to form a sample gas mixture (M_camp) and

regulating the state of the cleaning gas mixture (M_p) in order to keep the sample gas mixture (M_camp) and hence the unknown gas mixture (M_inc) in the predetermined desired state, in such a way as to keep the humidity of the sample gas mixture M_camp, and hence of the unknown gas mixture M_incconstant; and

wherein the unknown gas mixture (M_inc) is sample air (A_c) with unknown odour and the known gas mixture (M_n) is reference air (A_r), characterized in that the method comprises steps of;

calibrating the sensor with the reference air (A_r);

delivering a fraction of the sample air (A_c) into the chamber (3);

detecting the unknown odour in the sample air (A_c);

regulating the state of one of either the reference air (A_r) or the sample air (A_c) before both the sample air (A_c) and the reference air (A_r) flow into the chamber (3), and characterized in that the method comprises a step of making the temperature of the reference air (A_r) and that of the sample air (A_c) equal before the two types of air flow into the measuring chamber (3).