SYSTEM AND METHOD FOR OPTICAL ANALYSIS

• US 20080017799A1
• Filed: 02/01/2007
• Published: 01/24/2008
• Est. Priority Date: 07/20/2006
• Status: Active Grant

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Sas Photonics, LLC
• Inventors: Sting, Donald W., Ressler, Gregg, Saller, Jeffrey H.
• Granted Patent: US 7,582,869 B2
• Time in Patent Office: Days
• US Class Current: 250/339.01
• CPC Class Codes: G01N 2021/0339 Holders for solids, powders
• CPC Class Codes: G01N 2021/0389 Windows
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/3563 for analysing solids; Preparation of samples therefor

Abstract

An optical analysis system utilizing transmission spectroscopy for analyzing liquids and solids includes a source of optical energy, a sample, a movable optical energy transmission window, a fixed optical energy transmission window, and a detection system. The fixed transmission window remains fixed relative to the source of optical energy. The sample is selectively positioned between the movable and fixed optical energy transmission windows for analyzing the sample. The optical energy is transmitted through one of the windows, the sample, and the other window to obtain encoded optical energy as a result of transmitting the optical energy through the sample. A detection system receives the encoded optical energy for analysis. The movable optical energy transmission window is selectively movable relative to the fixed optical energy transmission window to repeatedly and precisely align and make readily accessible both windows and the sample.

Claims

1. An optical analysis system utilizing transmission spectroscopy for analyzing liquids and solids, comprising:

a source of optical energy;

a sample;

a movable optical energy transmission window;

a fixed optical energy transmission window, whereby the fixed transmission window remains fixed relative to the source of optical energy, the sample selectively being positioned between the movable and fixed optical energy transmission windows for analyzing the sample, the optical energy being transmitted through one of the windows, the sample, and the other window to obtain encoded optical energy as a result of transmitting the optical energy through the sample; and

a detection system for receiving the encoded optical energy for analysis, the movable optical energy transmission window being selectively movable relative to the fixed optical energy transmission window to repeatedly and precisely align and make readily accessible both windows and the sample.

2. The optical analysis system of claim 1 wherein the source of optical energy provides infrared optical energy.

3. The optical analysis system of claim 1, further including:

a movable apparatus, the movable transmission window being fixedly secured to the movable apparatus; and

a fixed apparatus, the fixed transmission window being fixedly secured to the fixed apparatus, the movable apparatus being movably coupled to the fixed apparatus, movement of the movable assembly to a first position repeatedly and precisely aligning the movable transmission window relative to the fixed transmission window for passing the optical energy through one of the windows, the sample, and the other window during a transmission sample analysis, and movement of the movable apparatus to a second position making readily accessible both windows and the sample.

4. The optical analysis system of claim 3, wherein an optical path length between the movable and fixed windows is maintained whenever the movable apparatus is in the first position.

5. The optical analysis system of claim 3, further including:

an inlet in the movable apparatus to pass the optical energy therethrough into a chamber in the movable apparatus; and

a mirror mounted in the chamber to direct the incoming optical energy from the inlet to the movable transmission window.

6. The optical analysis system of claim 5, further including:

an outlet in the movable apparatus to pass the optical energy therethrough out of the chamber in the movable apparatus, at least one mirror mounted in the chamber to direct the optical energy from the movable transmission window to the outlet.

7. The optical analysis system of claim 1 including:

a moveable apparatus including the moveable transmission window;

a fixed apparatus including the fixed transmission window; and

a bearing assembly secured between the moveable apparatus and the fixed apparatus, the moveable apparatus rotating within a portion of the fixed apparatus.

8. The optical analysis system of claim 7, wherein the movable window slides into and out of the sample.

9. The optical analysis system of claim 8, wherein the movable apparatus includes:

a projecting nose piece assembly with a generally convex spherical surface portion in which the movable transmission window is mounted, the generally convex spherical surface portion being received in a generally concave spherical surface portion in the fixed apparatus in which the fixed transmission window is mounted, sufficient clearance being provided between the two spherical surface portions to provide a space for receiving and containing the sample while maintaining a known path length between the fixed window and the movable window.

10. The optical analysis system of claim 1, including:

a moveable apparatus including the moveable transmission window;

a fixed apparatus including the fixed transmission window; and

a hinge pivotally securing the moveable apparatus to the fixed apparatus, the moveable apparatus pivoting around the hinge when moving relative to the fixed apparatus to position the movable apparatus in optical alignment with the fixed transmission window.

11. The optical analysis system of claim 10 wherein the detection system is affixed to the movable apparatus.

12. The optical analysis system of claim 10, wherein the movable transmission window is positioned over the sample before contacting the sample.

13. A sampling apparatus for infrared transmission analysis of a sample, comprising:

a movable infrared transmission window;

a fixed infrared transmission window;

wherein the movable infrared transmission window has a first position precisely located relative to and spaced from the fixed infrared transmission window, a sample contained in the space between the movable and fixed windows in said first position, infrared energy transmitted through one of the windows, the sample, and the other window resulting in infrared energy that is encoded with infrared characteristics of the sample; and

wherein the movable infrared transmission window has at least a second position relative to the fixed window for exposing both the windows to permit removal of the sample from the fixed window, cleaning of both windows, and placement of a new sample on the fixed transmission window.

14. The sampling apparatus for infrared transmission analysis as set forth in claim 13, further including:

a movable apparatus, the movable window being fixedly secured to the movable apparatus;

a fixed apparatus, the fixed window being fixedly secured to the fixed apparatus; and

a portion of the fixed apparatus selectively extending into a first detent in the movable apparatus to secure the movable apparatus to the fixed apparatus in the first position and selectively extending into a second circumferentially spaced detent in the movable assembly when the first movable transmission window is in its second position.

15. The optical analysis system of claim 14 further including:

a detection system affixed to and part of the movable apparatus.

16. The sampling apparatus for infrared transmission analysis as set forth in claim 14, wherein the movable apparatus is rotationally mounted to the fixed apparatus to permit the movable apparatus selectively to rotate about an axis that is substantially parallel to the fixed apparatus between the first and second positions of the first movable transmission window.

17. The sampling apparatus for infrared transmission analysis as set forth in claim 16, wherein the movable window shears the sample as the movable window is moved into the first position.

18. The sampling apparatus for infrared transmission analysis as set forth in claim 14, further including:

an adjustable setting device for adjustably establishing the first position of the movable transmission window relative to the fixed transmission window.

19. The sampling apparatus for infrared transmission analysis as set forth in claim 13, further including:

a movable apparatus, the movable window being fixedly secured to the movable apparatus;

a fixed apparatus, the fixed window being fixedly secured to the fixed apparatus; and

a hinge pivotally securing the movable apparatus to the fixed apparatus, the movable apparatus pivoting around the hinge when the movable window is moved between the first and second positions.

20. The sampling apparatus for infrared transmission analysis as set forth in claim 19, wherein the movable apparatus includes at least one mirror operative to deliver the infrared energy from an optical inlet in the movable apparatus to the movable transmission window in its first position, the sample, and the second fixed transmission window.

21. A method for performing an infrared transmission analysis of a sample, the method comprising:

defining an optical path, including a repeatable path length, between a source of optical energy and a detection system through a transmission sampling apparatus including a movable transmission window, a sample, and a fixed optical transmission window;

passing optical energy along the optical path through the transmission sampling apparatus to obtain optical energy encoded with characteristics of the sample;

analyzing the encoded optical energy in a detection system to analyze the sample; and

selectively exposing the first and second windows for sample extraction/insertion and maintaining the windows.

22. The method for performing an infrared transmission analysis of a sample as set forth in claim 21, wherein the defining step includes:

setting the movable optical transmission window to a first position relative to the fixed transmission window, the sample being between the movable and fixed windows when the movable window is in the first position.

23. The method for performing an infrared transmission analysis of a sample as set forth in claim 22, wherein the exposing step includes:

setting the movable optical transmission window to a second position relative to the fixed transmission window, the windows being separated from one another and exposed to the user when the movable window is in the second position.

24. The method for performing an infrared transmission analysis of a sample as set forth in claim 23, wherein setting the movable window to the first position and setting the movable window to the second position include:

moving the movable window relative to the fixed window.

25. The method for performing an infrared transmission analysis of a sample as set forth in claim 21, wherein defining the optical path includes:

positioning the movable window in optical alignment with the sample.

26. The method for performing an infrared transmission analysis of a sample as set forth in claim 21, further including:

adjusting the repeatable path length between the movable and fixed windows.

27. The method for performing an infrared transmission analysis of a sample as set forth in claim 21, further including:

mounting the movable window in a movable apparatus and the fixed window in a fixed apparatus.

28. The method for performing an infrared transmission analysis of a sample as set forth in claim 27, further including:

rotating the movable apparatus relative to the fixed apparatus.

29. The method for performing an infrared transmission analysis of a sample as set forth in claim 28, further including:

selectively retaining the movable assembly in a first position in which the movable window is in optical alignment with and closely spaced to the fixed window and in a second position in which the movable window is separated from the fixed window to permit window maintenance and sample insertion and removal.

30. The method for performing an infrared transmission analysis of a sample as set forth in claim 27, further including:

pivoting the movable apparatus relative to the fixed apparatus.