Spectrometer for analysis of multiple samples

• US 20070086006A1
• Filed: 10/18/2005
• Published: 04/19/2007
• Est. Priority Date: 10/18/2005
• Status: Active Grant

• Current Assignee: Thermo Electron Scientific Instruments LLC (Thermo Fisher Scientific Incorporated)
• Original Assignee: Thermo Electron Scientific Instruments LLC (Thermo Fisher Scientific Incorporated)
• Inventors: Iverson, John, Ebersole, Matthew
• Granted Patent: US 7,339,668 B2
• Time in Patent Office: Days
• US Class Current: 356/319
• CPC Class Codes: G01N 2021/3137 with selection of wavelengths after the sample
• CPC Class Codes: G01N 2021/317 Special constructive features
• CPC Class Codes: G01N 21/253 for batch operation, i.e. multisample apparatus analytical automats G01N35/00
• CPC Class Codes: G01N 21/31 Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry G01N21/72 takes precedence
• CPC Class Codes: G01N 2201/0826 Fibre array at source, distributing

Abstract

A spectrometer (100) includes a light source (102) providing output light (106) to the bundled input ends (108) of multiple light pipes (110). The light pipes (110) branch into sets (118) between their input ends (108) and output ends (114), with each set (118) illuminating a sample detector (126) (via a sample chamber (122)) for measuring light scattered or emitted by a sample, or a reference detector (128) for obtaining a reference/datum measurement of the supplied light, so that comparison of measurements from the sample detector (126) and the reference detector (128) allows compensation of the sample detector measurements for drift. Efficient and accurate measurement is further assured by arraying the multiple light pipes (110) in each set (118) about the input bundle (116) so that each set receives at least substantially the same amount of light from the light source (102).

Claims

1. A spectrometer comprising:

a. an interferometer providing an output light image;

b. sample chambers for receiving samples to be spectrometrically analyzed;

c. multiple light pipes, each light pipe extending between input end and an opposing output end, wherein;

(1) the input ends are bundled, with the bundled input ends receiving the output light image from the interferometer;

(2) the light pipes branch into sets between their input ends and output ends, wherein at least some of the sets;

(a) include two or more of the light pipes, wherein at least some of these light pipes have their input ends spaced from each other within the bundle by input ends of light pipes of other sets;

(b) each extend to have their output ends provide the output light image from the interferometer to one of the sample chambers.

2. The spectrometer of claim 1 wherein the bundled input ends are collectively surrounded by a circumferential boundary which is shaped at least substantially complementary to the output light image.

3. The spectrometer of claim 2 wherein the circumferential boundary is at least substantially noncircular.

4. The spectrometer of claim 2 wherein the circumferential boundary is at least substantially polygonal.

5. The spectrometer of claim 1 wherein at least some of the light pipe sets differ in one or more of:

a. the numbers of light pipes included therein;

b. the diameters of the light pipes included therein; and

c. the wavelengths of light passed by the light pipes included therein.

6. The spectrometer of claim 1 further comprising a reference detector, wherein:

a. at least one of the sets of light pipes extends to have its output ends provide the output light image from the interferometer to the reference detector, and

b. no sample chamber is situated between the output ends and the reference detector.

7. A spectrometer comprising:

a. a light source;

b. at least two sample chambers;

c. multiple light pipes having input ends adjacently arrayed in a bundle and opposing output ends, wherein;

(1) the bundled input ends receive light from the light source, and

(2) the light pipes define independent optical paths providing light from the light source to each of;

(a) the sample chambers, and

(b) a reference location isolated from the sample chambers, wherein none of the paths receives light from any of the other optical paths;

d. at least two detectors wherein;

(1) at least one of the detectors is a reference detector receiving light from the reference location, and

(2) at least one of the detectors is a chamber detector receiving light from the light source via one of the sample chambers, whereby measurements generated by the reference and may be compared.

8. The spectrometer of claim 7 wherein at least some of the optical paths each include two or more light pipes having input ends nonadjacently spaced about the bundle.

9. The spectrometer of claim 7 wherein:

a. each of the optical paths to the sample chambers and the reference location includes multiple light pipes, and

b. at least some of the light pipes within each of the optical paths have input ends which are nonadjacently spaced within the bundle by the input ends of light pipes of other optical paths.

10. The spectrometer of claim 9 wherein the bundled input ends of the light pipes are collectively surrounded by an at least substantially noncircular circumferential boundary.

11. The spectrometer of claim 9 wherein the bundled input ends of the light pipes are collectively surrounded by an at least substantially polygonal circumferential boundary.

12. The spectrometer of claim 7 wherein at least some of the optical paths to the sample chambers and reference location differ in at least one of:

a. the numbers of light pipes included therein;

b. the diameters of the light pipes included therein; and

c. the wavelengths of light passed by the light pipes included therein.

13. The spectrometer of claim 12 wherein at least some of the optical paths include two or more light pipes with input ends which are nonadjacently spaced within the bundle by light pipes of other ones of the optical paths.

14. The spectrometer of claim 7 wherein:

a. at least some of the optical paths are each provided by multiple light pipes, and

b. the boundary circumferentially surrounding the bundled input ends is at least substantially noncircular.

15. The spectrometer of claim 14 wherein the boundary circumferentially surrounding the bundled input ends is at least substantially polygonal.

16. The spectrometer of claim 7 wherein:

a. the light source has a filament therein, and emits an image of the filament to the bundled input ends; and

b. the bundle has a profile, as seen on a plane oriented at least substantially perpendicular to an axis along which the image of the filament travels to the input ends, shaped at least substantially complementary to the image of the filament.

17. The spectrometer of claim 7 further comprising an interferometer interposed between the light source and the bundled input ends of the light pipes, wherein the interferometer provides light from the light source to the bundled input ends.

18. The spectrometer of claim 7 wherein:

a. at least one of the detectors receives light from the light source via one of the sample chambers, and

b. at least one of the detectors simultaneously receives light from the reference location.

19. The spectrometer of claim 7 wherein at least one of the detectors is movable between sample chambers, whereby the detector receives light from the light source via different sample chambers in sequence.

20. The spectrometer of claim 7 wherein one or more of the detectors receives light from the reference location after receiving light via one of the sample chambers.

21. The spectrometer of claim 7 wherein at least one of the detectors is movable between one of the sample chambers and the reference location.

22. The spectrometer of claim 7 wherein at least one of:

a. the light pipes providing the light from the light source to the reference location, and

b. the one or more detectors receiving the light from the reference location, is movable relative to the other.

23. A spectrometric method comprising the steps of:

a. providing light along several light pipes from a light source to several sample chambers, the sample chambers bearing samples to be spectrometrically analyzed, with the light then being received by chamber detectors from the sample chambers, and wherein;

(1) the light pipes include input ends which receive the light from the light source, with the input ends being bundled;

(2) at least some of the sample chambers each receive light from the light source via several of the light pipes; and

(3) at least some of these several light pipes have input ends spaced from each other within the bundle by light pipes providing light to other ones of the sample chambers;

b. providing light along several light pipes from the light source to a reference detector, with the reference detector being isolated from receiving light from the sample chambers;

c. comparing chamber light measurements generated by the chamber detectors to a reference light measurement generated by the reference detector.

24. The spectrometric method of claim 23 wherein at least some of the several light pipes providing light from the light source to the reference detector have input ends spaced from each other by light pipes which provide light from the light source to the sample chambers.

25. The spectrometric method of claim 23 wherein at least some of the sample chambers differ in at least one of:

a. the numbers of light pipes from which the sample chambers receive light;

b. the diameters of the light pipes from which the sample chambers receive light; and

c. the wavelengths of light passed by the light pipes from which the sample chambers receive light.

26. The spectrometric method of claim 23 wherein the steps of:

a. providing light to the sample chambers, and

b. providing light to the reference detector, occurs simultaneously.

27. The spectrometric method of claim 23 wherein the step of providing light to the sample chambers is performed by providing light to different ones of the sample chambers in sequence.

28. The spectrometric method of claim 27 wherein light is provided to the reference detector simultaneously with light being provided to each of the sample chambers.

29. The spectrometric method of claim 23 wherein the step of providing light to the reference detector occurs at a different time than the step of providing light to the sample chambers.