EPOXY MOLDED GAS CELL FOR OPTICAL MEASUREMENT AND METHOD OF FORMING

• US 20140333924A1
• Filed: 11/30/2012
• Published: 11/13/2014
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: SenseAir AB (Asahi Kasei Corporation)
• Original Assignee: SenseAir AB (Asahi Kasei Corporation)
• Inventors: Martin, Hans Gran Evald
• Granted Patent: US 9,448,159 B2
• Time in Patent Office: Days
• US Class Current: 356/246
• CPC Class Codes: B29C 45/02 Transfer moulding, i.e. transferring the required volume of moulding material by a plunger from a "shot" cavity into a mould cavity
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2509/00 Use of inorganic materials not provided for in groups B29K2503/00 - B29K2507/00, as filler
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: B29L 2011/0083 Reflectors
• CPC Class Codes: G01N 2021/0314 Double pass, autocollimated path
• CPC Class Codes: G01N 2021/0378 Shapes
• CPC Class Codes: G01N 21/01 Arrangements or apparatus for facilitating the optical investigation
• CPC Class Codes: G01N 21/031 Multipass arrangements
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/0228 Moulded parts

Abstract

The present invention relates to a gas cell (1) for optical measurements of gas content and/or concentration comprising a cavity (1a), at least one aperture (11) for gas exchange, at least one first socket (12) for light emitting means (2) and at least one second socket (13) for light detecting means (3). The length of an optical measuring path (A) through the cavity (1a) is defined by a direct or indirect distance between a light emitting means (2) in the first socket (12) and a light detecting means (3) in the second an epoxy mold compound is used to form at least the parts of the gas cell (1) that define the optical measuring path (A).

Claims

1. Gas cell for optical measurements of gas content and/or concentration in a macroscopic system, the gas cell comprising a cavity, at least one aperture for gas exchange, at least one first socket for a light emitting means, at least one second socket for a light detecting means, and where the length of an optical measuring path through said cavity is defined by a direct or indirect distance between a light emitting means positioned in said first socket and a light detecting means positioned in said second socket, characterized in, that an epoxy mold compound (EMC) is used to form at least the parts of said gas cell that define said optical measuring path.

2. Gas cell according to claim 1, characterized in, that light emitting means is positioned in said first socket, and that said light emitting means is at least partly encapsulated in said EMC.

3. Gas cell according to claim 1 or 2, characterized in, that said light emitting means is covered by optically transparent material.

4. Gas cell according to claim 3, characterized in, that said optically transparent material is optically transparent EMC.

5. Gas cell according to any preceding claim, characterized in, that light detecting means is positioned in said second socket, and that said light detecting means is at least partly encapsulated in said EMC.

6. Gas cell according to claim 1 or 5, characterized in, that said light detecting means is covered by optically transparent material.

7. Gas cell according to claim 6, characterized in, that said optically transparent material is optically transparent EMC.

8. Gas cell according to claim 6, characterized in, that said optically transparent material is an optical filter.

9. Gas cell according to any preceding claim, characterized in, that said cavity comprises at least one light reflecting means, and that said measuring path includes a reflection in said light reflecting means.

10. Gas cell according to claim 9, characterized in, that said light reflecting means is a light reflecting mirror, and that said light reflecting mirror is at least partly encapsulated in said EMC.

11. Gas cell according to claim 10, characterized in, that a piezo transducer is positioned behind said reflecting mirror, adapted to adjust the position of said reflecting mirror, and that said piezo transducer is encapsulated in said EMC.

12. Gas cell according to claim 9, characterized in, that said light reflecting means is a reflecting surface, and that the shape of said reflecting surface is formed in said EMC.

13. Gas cell according to any one of claims 9 to 12, characterized in, that heating means is positioned behind said light reflecting means, and that said heating means is encapsulated in said EMC.

14. Gas cell according to any preceding claim, characterized in, that electronic components, such as amplifying means, computing means, memory means, or driver electronics for said light emitting means, related to said gas cell are encapsulated in said EMC.

15. Gas cell according to any preceding claim, characterized in, that optical components, such as optical filtering means, beam splitting means or optical gratings, related to said gas cell are at least partly encapsulated in said EMC.

16. Gas cell according to any preceding claim, characterized in, that gas filtering means, such as filter to prevent contamination of said cavity, is positioned in said aperture, and that said gas filtering means is at least partly encapsulated in said EMC.

17. Gas cell according to any preceding claim, characterized in, that said EMC is a highly mineral filled Epoxy.

18. Gas cell according to any preceding claim, characterized in, that the length of the optical measuring path is in the range of centimeters.

19. Method to form a gas cell for optical measurements of gas content and/or concentration comprising a cavity, at least one aperture for gas exchange, at least one first socket for a light emitting means and at least one second socket for a light detecting means, and where the length of an optical measuring path through said cavity is defined by a direct or indirect distance between a light emitting means positioned in said first socket and a light detecting means positioned in said second socket, characterized in, that an epoxy mold compound (EMC) is used to form at least the part of said gas cell that define said optical path.

20. Method according to claim 19, characterized in, that light emitting means are positioned in said first socket, and that said light emitting means is at least partly encapsulated in said EMC.

21. Method according to claim 19 or 20, characterized in, that said light emitting means is covered by optically transparent material.

22. Method according to claim 21, characterized in, that said optically transparent material is optically transparent EMC.

23. Method according to any one of claims 19 to 22, characterized in, that light detecting means are positioned in said second socket, and that said light detecting means is at least partly encapsulated in said EMC.

24. Method according to claim 19 or 23, characterized in, that said light detecting means is covered by optically transparent material.

25. Method according to claim 24, characterized in, that said optically transparent material is optically transparent EMC.

26. Method according to claim 24, characterized in, that said optically transparent material is an optical filter.

27. Method according to any one of claims 19 to 26, where said cavity comprises at least one light reflecting means, and where said measuring path includes a reflection in said light reflecting means, characterized in, that said light reflecting means is a light reflecting mirror, and that said light reflecting mirror is at least partly encapsulated in said EMC.

28. Method according to claim 27, characterized in, that a piezo transducer is positioned behind said reflecting mirror, adapted to adjust the position of said reflecting mirror, and that said piezo transducer is encapsulated in said EMC.

29. Method according to any one of claims 19 to 26, where said cavity comprises at least one light reflecting means, and where said measuring path includes a reflection in said light reflecting means, characterized in, that said light reflecting means is a reflecting surface, and that the shape of said reflecting surface is formed in said EMC.

30. Method according to any one of claims 27 to 29, characterized in, that heating means is positioned behind said light reflecting means, and that said heating means is encapsulated in said EMC.

31. Method according to any one of claims 19 to 30, characterized in, that electronic components, such as amplifying means, computing means, memory means, or driver electronics for said light emitting means, related to said gas cell are encapsulated in said EMC.

32. Method according to any one of claims 19 to 31, characterized in, that optical components, such as optical filtering means, beam splitting means or optical gratings, related to said gas cell are at least partly encapsulated in said EMC.

33. Method according to any one of claims 19 to 32, characterized in, that gas filtering means, such as filter to prevent contamination of said cavity, is positioned in said aperture, and that said gas filtering means is at least partly encapsulated in said EMC.

34. Method according to any one of claims 19 to 33, characterized in, that said gas cell is formed by means of transfer moulding.

35. Method according to claim 34, characterized in, that several gas cells are produced in parallel in one and the same production tool.

36. Method according to any one of claims 19 to 35, characterized in, the use of a highly mineral filled Epoxy for said EMC.

37. Method according to any one of claims 19 to 36, characterized in, that the length of the optical measuring path is in the range of centimeters.