Turbidity sensors and probes

• US 8,488,122 B2
• Filed: 02/23/2011
• Issued: 07/16/2013
• Est. Priority Date: 05/05/2010
• Status: Active Grant

• Current Assignee: YSI Incorporated (Xylem, Inc.)
• Original Assignee: YSI Incorporated (Xylem, Inc.)
• Inventors: Dong, Guoquan, Lauchner, Daniel L.
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US13/033,103
• Publication Number:
  US 20110273710A1
• Time in Patent Office: 874 Days
• Field of Search: 356445-448
• US Class Current: 356/445
• CPC Class Codes: G01N 2021/152 Scraping; Brushing; Moving band
• CPC Class Codes: G01N 21/53 within a flowing fluid, e.g. smoke
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01N 21/8507 Probe photometers, i.e. with optical measuring part dipped into fluid sample
• CPC Class Codes: G01N 33/18 Water

Abstract

Turbidity heads for a turbidity sensor or probe and the resulting sensor are disclosed that include a light source providing an outgoing light ray, a photodetector capable of detecting an incoming light ray; an isolator separating the light source from the detector portion; and a first reflector in the path of either the outgoing light ray or the incoming light ray. The first reflector is positioned to reflect either the outgoing light ray or the incoming light ray to achieve a measurement angle defined between the outgoing light ray and the incoming light ray of ninety degrees plus-or-minus two and a half degrees to comply with the standard ISO 7027 for turbidity measurement.

Claims

1. A turbidity head for a turbidity sensor or probe comprising:

a light source providing an outgoing light ray toward a fluid sample;

a detector capable of detecting an incoming light ray reflected from the fluid sample;

an isolator separating the light source from the detector portion; and

a first reflector in the path of either the outgoing light ray or the incoming light ray;

wherein the first reflector is positioned to reflect either the outgoing light ray or the incoming light ray to achieve a measurement angle defined between the outgoing light ray and the incoming light ray of ninety degrees plus-or-minus two and a half degrees.

2. The turbidity head of claim 1, wherein the first reflector is positioned at a tilt angle between 0°

to 45°

.

3. The turbidity head of claim 2 wherein the first reflector is positioned at a tilt angle between about 10°

to about 30°

.

4. The turbidity head of claim 1, wherein the first reflector includes a prism, a reflective film, a reflective coating, and combinations thereof.

5. The turbidity head of claim 4, wherein the first reflector is a prism having one reflective side.

6. The turbidity head of claim 5, wherein the first reflector is positioned to reflect the outgoing light ray and a second reflector is positioned to reflect the incoming light ray.

7. The turbidity head of claim 5, wherein the reflective side includes the reflective coating or the reflective film thereon.

8. The turbidity head of claim 1, wherein the first reflector is positioned such that the incident angle is less than the critical angle.

9. The turbidity head of claim 1, wherein the turbidity head has a central longitudinal axis and whichever of the light source or the photo detector is in the path of the first reflector has a central longitudinal axis that is generally parallel to the central longitudinal axis of the turbidity head.

10. The turbidity head of claim 9, wherein the reflector is a parallelepiped prism, the prism being positioned at a tilt angle between 0°

to 45°

that places the second end of the prism closer to the central longitudinal axis of the turbidity head than the first end of the prism.

11. The turbidity head of claim 1, further comprising a housing having a maximum diameter of about 13 mm, the housing enclosing the light source, the photodetector, the isolator, and the first reflector.

12. The turbidity head of claim 11, wherein the housing is a cap having a closed end that includes an optics aperture.

13. The turbidity head of claim 4, wherein the first reflector is a reflective film.

14. The turbidity head of claim 13, wherein the first reflector is positioned to reflect the outgoing light ray and a second reflector is positioned to reflect the incoming light ray.

15. The turbidity head of claim 1, wherein the turbidity head has a central longitudinal axis and whichever of the light source or the photo detector that does not include the reflector has a central longitudinal axis that is oriented at about a 5°

to about a 60°

angle to the central longitudinal axis of the turbidity head.

16. A turbidity sensor comprising:

a watertight housing that houses a light source providing an outgoing light ray toward a fluid sample, a detector capable of detecting an incoming light ray reflected from the fluid sample, an isolator separating the light source from the detector portion, a first reflector in the path of either the outgoing light ray or the incoming light ray, and a circuit board electrically coupled to the light source and the detector;

wherein the first reflector is positioned to reflect either the outgoing light ray or the incoming light ray to achieve a measurement angle defined between the outgoing light ray and the incoming light ray of ninety degrees plus-or-minus two and a half degrees.

17. The turbidity sensor of claim 16, further comprising an electrical connector electrically coupled to the circuit board, the electrical connector being capable of electrically coupling the circuit board to a water monitoring device.

18. The turbidity sensor of claim 17, wherein the electrical connector is a wet mateable connector.

19. The turbidity sensor of claim 16, wherein the water tight housing includes a cap that covers an optics receptacle that receives the light source, the photodetector, and the reflector.

20. The turbidity sensor of claim 16, further comprising a second reflector, wherein the first reflector is positioned to reflect the outgoing light ray and the second reflector is positioned to reflect the incoming light ray.