Cooled mounting for light detector

• US 6,903,329 B2
• Filed: 11/19/2002
• Issued: 06/07/2005
• Est. Priority Date: 08/21/2001
• Status: Active Grant

• Current Assignee: SPX Corporation
• Original Assignee: SPX Corporation
• Inventors: Gentala, Robert A.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): MONBLEAU, DAVIENNE N
• Application Number:
  US10/298,645
• Publication Number:
  US 20030098412A1
• Time in Patent Office: 931 Days
• Field of Search: 372 34- 36, 250/214.R, 250/238, 250/239, 250/339.05, 250/339.12, 250/339.13, 250/338.5, 250/252.1, 356/326, 356/328, 356/432, 356/437, 356/438, 356/440, 257/433, 257/712, 257/717, 257/718
• US Class Current: 250/238
• CPC Class Codes: G01N 1/2252 in a vehicle exhaust
• CPC Class Codes: G01N 2001/2264 with dilution
• CPC Class Codes: G01N 2021/3155 Measuring in two spectral ranges, e.g. UV and visible
• CPC Class Codes: G01N 2021/3174 Filter wheel
• CPC Class Codes: G01N 2021/3513 Open path with an instrumental source
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/534 by measuring transmission alone, i.e. determining opacity

Abstract

A new type of mounting mechanism for a light detector that cools the mounting for a light detector such that the maximum efficiency of the light detector'"'"'s internal cooler can be achieved despite an elevated enclosure temperature, leading to more stable measurements of light from the detector. This same mounting provides thermal isolation from a baseplate, to which other optical path components are attached.

Claims

1. An optical system for a gas component analysis, comprising:

a first emitter for emitting a first light beam having a first spectrum;

a second emitter for emitting a second light beam at a second spectrum;

a first receiver for receiving the first light beam; and

a second receiver for receiving the second light beam, wherein the first light beam travels along a first path in a first direction and the second light beam travels along a second path in a second direction and at least a portion of the first light path overlaps with at least a portion of the second light path to form an overlapping beam, and at the overlapping beam the first direction is opposite to the second direction;

wherein the first and second light beams are projected across a vehicle path, and the first and second emitters and first and second receivers are located on one side of the vehicle path, and wherein the system comprises a reflector located at the other side of the vehicle path to direct the first and second beams from the first and second emitters to the first and second receivers respectively, wherein one of the first and second receivers is mounted by a bisected mounting, comprising;

a baseplate;

an insulating member attached to said baseplate; and

a detector side attached to said insulating member, wherein said insulating member thermally isolates said baseplate from said detector side.

2. The bisected mounting as recited in claim 1 further comprising a cooling device located on said detector side.

3. The bisected mounting as recited in claim 2 wherein said cooling device is a thermoelectric cooling device.

4. The bisected mounting as recited in claim 2 wherein said cooling device is a liquid cooling device.

5. The bisected mounting as recited in claim 1 wherein said baseplate is made of aluminum.

6. The bisected mounting as recited in claim 1 wherein said baseplate is coated in areas that are not in contact with said insulating member.

7. The bisected mounting as recited in claim 6 wherein said coating is a powder coating.

8. The bisected mounting as recited in claim 6 wherein said coating is an anodized coating.

9. The bisected mounting as recited in claim 1 further comprising fiber washers located between said insulating member and said baseplate, and between said insulating member and said detector side.

10. The bisected mounting as recited in claim 1 further comprising thermal grease located between said insulting member and said baseplate, and between said insulating member and said detector side.

11. An optical system for a gas component analysis, comprising:

a first emitter for emitting a first light beam having a first spectrum;

a second emitter for emitting a second light beam at a second spectrum;

a first receiver for receiving the first light beam; and

a second receiver for receiving the second light beam, wherein the first light beam travels alone a first path in a first direction and the second light beam travels along a second path in a second direction and at least a portion of the first light path overlaps with at least a portion of the second light path to form an overlapping beam, and at the overlapping beam the first direction is opposite to the second direction;

wherein the first and second light beams are projected across a vehicle path, and the first and second emitters and first and second receivers are located on one side of the vehicle path, and wherein the system comprises a reflector located at the other side of the vehicle path to direct the first and second beams from the first and second emitters to the first and second receivers respectively, wherein one of the first and second receivers is mounting by a bisected mounting, comprising;

a means for detecting a signal on the detector side of the light detector;

a means for transmitting said signal to a baseplate side of the light detector that is thermally isolated from the detector side by an insulating member.

12. The system as recited in claim 11 further comprising a means for cooling the detector side using a cooling device.

13. The system as recited in claim 11 further comprising a means for cooling the detector side using a thermoelectric cooler.

14. The system as recited in claim 11 further comprising a means for cooling the detector side using a liquid cooling device.

15. The system as recited in claim 11 wherein said transmitting means transmits said signal to said baseplate, said baseplate having being made of aluminum.

16. The system as recited in claim 11 wherein said transmitting means transmits said signal to said baseplate, said baseplate having a coating in areas that are not in contact with said insulating member.

17. The system as recited in claim 11 wherein said transmitting means transmits said signal said baseplate, said baseplate having a powder coating.

18. The system as recited in claim 11 wherein said transmitting means transmits said signal to said baseplate, said baseplate having an anodized coating.

19. The system as recited in claim 11 wherein said transmitting means transmits said signal to said baseplate, said baseplate having fiber washers located between said insulating member and said baseplate, and between said insulating member and said detector side.

20. The system as recited in claim 11 wherein said transmitting means transmits said signal to said baseplate, said baseplate having thermal grease located between said insulating member and said baseplate, and between said insulating member and said detector side.