EXTENDED SOLID ANGLE TURBIDITY SENSOR

Abstract

A turbidity sensor featuring a signal processor or processing module configured to: receive signaling containing information about light reflected off suspended matter in a liquid and sensed by a linear sensor array having rows and columns of optical elements; and determine corresponding signaling containing information about a concentration of turbidity of the liquid, based upon the signaling received

Claims

1. Apparatus comprising: a signal processor or processing module configured to: receive signaling containing information about light reflected off suspended matter in a liquid and sensed by a linear sensor array having rows and columns of optical elements; and determine corresponding signaling containing information about a concentration of a parameter of the liquid, based upon the signaling received

2. Apparatus according to claim 1, wherein the parameter is turbidity of the liquid.

3. Apparatus according to claim 1, wherein the apparatus comprises the linear sensor array.

4. Apparatus according to claim 3, wherein the linear sensor array comprises a linear photodiode array.

5. Apparatus according to claim 3, wherein the linear sensor array comprises a linear CCD array.

6. Apparatus according to claim 3, wherein the linear sensor array comprises a linear CMOS array.

7. Apparatus according to claim 3, wherein the linear sensor array comprises a closed cylinder sensor array having a three-dimensional cylindrical array of the rows and columns of the optical elements.

8. Apparatus according to claim 1, wherein the apparatus is a turbidity sensor.

9. Apparatus according to claim 1, wherein the apparatus comprises a quasi-collimated light source having a length and being configured to provide the light, including quasi-collimated light, along a corresponding length of the linear sensor array.

10. Apparatus according to claim 1, wherein the signal processor or processing module is configured to determine the parameter based upon an attenuation of an optical signal sensed across the linear sensor array, including along the length and width of the linear sensor array.

11. Apparatus according to claim 1, wherein the linear sensor array comprises a two-dimensional array of the optical elements that are individually addressable.

12. Apparatus according to claim 2, wherein the signal processor or processing module is configured to determine the turbidity based upon a spatial gradient of an optical signal sensed across the linear sensor array that contains information about the concentration of the turbidity.

13. Apparatus according to claim 12, wherein the optical elements are individually addressable by the signal processor or processing module.

14. Apparatus according to claim 12, wherein either the rows or the columns of the optical elements are connected in parallel and addressable by the signal processor or processing module; the apparatus may include a transmission photodiode located at an end of the linear sensor array, opposite the light source, configured to respond to the light reflected off the suspended matter and provide transmission photodiode signaling containing information about the same; and the signal processor or processing module may be configured to receive the photodiode signaling and correct the corresponding signaling for drift or the inner filter effect.

15. A method comprising: receiving, with a signal processor or processing module, signaling containing information about light reflected off suspended matter in a liquid and sensed by a linear sensor array having rows and columns of optical elements; and determining, with the signal processor or processing module, corresponding signaling containing information about a concentration of a parameter of the liquid, based upon the signaling received

16. A method according to claim 15, wherein the parameter is turbidity of the liquid.

17. A method according to claim 15, wherein the method comprises configuring the linear sensor array as a linear photodiode array, a linear CCD array or a linear CMOS array.

18. A method according to claim 15, wherein the method comprises configuring the linear sensor array as a closed cylinder sensor array having a three-dimensional cylindrical array of the rows and columns of the optical elements.

19. A method according to claim 15, wherein the method comprises determining the parameter based upon an attenuation of an optical signal sensed across the linear sensor array.

20. A method according to claim 15, wherein the method comprises configuring a light source to provide the light, including using a quasi-collimated light source to provide quasi-collimated light.

21. A turbidity sensor comprising: a quasi-collimated light source having a length and being configured to provide quasi-collimated light to a liquid sample; a linear sensor array having rows and columns of optical elements and configured to sense light reflected off suspended matter in the liquid sample along the length of the collimated light source and provide signaling containing information about the light reflected off the suspended matter; and a signal processor or processing module configured to: receive the signaling; and determine corresponding signaling containing information about a concentration of turbidity of the liquid, based upon the signaling received

22. A turbidity sensor according to claim 21, wherein the linear sensor array comprises a linear photodiode array, a linear CCD array, or a linear CMOS array.

23. A turbidity sensor according to claim 21, wherein the signal processor or processing module is configured to determine the turbidity based upon an attenuation of an optical signal sensed across the linear sensor array, including along the length and width of the linear sensor array.

24. A turbidity sensor according to claim 21, wherein the signal processor or processing module is configured to determine the turbidity based upon a spatial gradient of an optical signal sensed across the linear sensor array that contains information about the concentration of the turbidity.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0043] The drawing, which are not necessarily drawn to scale, includes FIGS. 1-6B, as follows:

[0044] FIG. 1 is a diagram of a spatial distribution of scattered radiation of a single turbid particle that is approximated by a sphere, resulting in 4π [steradians] solid angle of scattered radiation that is known in the art.

[0045] FIG. 2A is a block diagram of apparatus, including a turbidity sensor, according to some embodiments of the present invention.

[0046] FIG. 2B is a block diagram of a linear sensor array having rows and columns of optical elements, according to some embodiments of the present invention.

[0047] FIG. 3 is a three dimension perspective view of a quasi-collimated light source that provides a quasi-collimated light in relation to a linear sensor array, according to some embodiments of the present invention.

[0048] FIG. 4 is a side view of that shown in FIG. 3 showing captured backscatter radiation by the linear sensor array, according to some embodiments of the present invention.

[0049] FIG. 5 is a graph of relative sensor response versus relative concentration, e.g., showing a sensitivity comparison of the assignee's contemporary EXO turbidity sensor (solid line with dots) vs. the linear array turbidity sensor (solid line). Note that the graph shows simulated data based on a physical model of the design according to the present invention.

[0050] FIG. 6A is an isometric view showing of a three-dimensional rendering of solid angle capture for an idealized long-cylinder shell geometry, e.g., such as a 3-D cylindrical linear sensor array, according to the present invention.

[0051] FIG. 6B is a cross-sectional view showing of the idealized long-cylinder shell geometry, e.g., such as the 3-D cylindrical linear sensor array.

[0052] To reduce clutter in the drawing, each Figure in the drawing does not necessarily include every reference label for every element shown therein.

DETAILED DESCRIPTION OF BEST MODE OF THE INVENTION

[0053] FIG. 2 shows apparatus 10, including a turbidity sensor, according to the present invention having a quasi-collimated light source 20, a linear sensor array 30, and a signal processor or processing module 40.

[0054] The signal processor or processing module 40 may be configured to [0055] receive signaling containing information about light Lr reflected off suspended matter in a liquid and sensed by the linear sensor array 30 having rows and columns of optical elements (r1, c1; r1, c2; r1, c3; r1, c4; r1, c5; r1, c6; r1, c7; r1, c8; . . . ; r1, cn; r2, c1; r2, c2; r2, c3; r2, c4; r2, c5; r2, c6; r2, c7; r2, c8; . . . ; r2, cn; r3, c1; r3, c2; r3, c3; r3, c4; r3, c5; r3, c6; r3, c7; r3, c8; . . . ; r3, cn; . . . ; rn, c1; rn, c2; rn, c3; rn, c4; rn, c5; rn, c6; rn, c7; rn, c8; . . . ; rn, cn); and [0056] determine corresponding signaling containing information about a concentration of parameter of the liquid, based upon the signaling received

The Parameter

[0057] By way of example, the parameter may include the concentration of turbidity in the liquid, and the apparatus may be, or take the form of, a turbidity sensor. However, the scope of the invention is not intended to be limited to any particular type or kind of parameter being sensed in a liquid either now known or later developed in the future.

The Linear Sensor Array 30

[0058] By way of example, the apparatus 10 may include the linear sensor array 30, e.g., such as a linear photodiode array, a linear charge-coupled device (CCD) array, a linear CMOS array. In particular, the linear sensor array 30 may include a two-dimensional array of rows and columns of optical elements, e.g., like that shown in FIG. 2B, that are individually addressable. Linear sensor arrays are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.

[0059] By way of example, linear sensors arrays are disclosed in the following U.S. Pat. Nos. 9,020,202; 8,022,349; 7,956,341; 7,040,538; 5,252,818; and 4,193,057, which are all hereby incorporated by reference.

FIGS. 3 and 4

[0060] By way of example, the apparatus 10 may include the source 20 configured to provide the light Lc, including quasi-collimated light, along a corresponding length of the linear sensor array 30, e.g., as shown in FIGS. 2 and 3, e.g., through a liquid sample arranged in relation to the light source 20 and the linear sensor array 30 so as to reflect the light Lr off suspended matter in the liquid sample being monitored or tested onto the linear sensor array 30. For example, the light Lr may be reflected radially (FIG. 3) and backwards (FIG. 4), i.e., backscattered reflected light or radiation.

[0061] As a person skilled in the art would appreciate, quasi-collimated light sources are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.

[0062] FIG. 4 shows captured backscatter radiation by the linear sensor array 30, where backscattered radiation is understood to be light reflected of the suspended matter in the liquid sample that travels backwards, consistent with that shown.

The Signal Processor or Processing Module 40

[0063] By way of example, the signal processor or processing module 40 may be configured to determine the parameter, including turbidity, based upon an attenuation of an optical signal sensed across the linear sensor array, including its length and width. Techniques for sensing the attenuation of the optical signal, e.g., in relation to the concentration of turbidity in the liquid, are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.

[0064] By way of example, the signal processor or processing module 40 may be configured to determine the concentration of turbidity based upon a spatial gradient of the optical signal sensed across the linear sensor array. As a person skilled in the art would appreciate, techniques for determining the concentration of turbidity in a liquid based upon a spatial gradient of an optical signal are known in the art, e.g., consistent with that set forth herein re PCT/US2008/059575, which is hereby incorporated by reference in its entirety, and the scope of the invention is not intended to be limited to any particular type or kind of technique either now known or later developed in the future.

[0065] In an alternative embodiment, either the rows or the columns of the optical elements may be connected in parallel and addressable by the signal processor or processing module 40; the apparatus 10 may include a transmission photodiode 30a located at an end of the linear sensor array 30, opposite the light source 20, configured to respond to the light L reflected off the suspended matter and provide transmission photodiode signaling containing information about the same; and the signal processor or processing module 40 may be configured to receive the photodiode signaling and correct the corresponding signaling for drift or the inner filter effect.

Implementation of Signal Processing Functionality

[0066] By way of example, the functionality of the signal processor or processing module 40 may be implemented using hardware, software, firmware, or a combination thereof. In a typical software implementation, the signal processor 40 would include one or more microprocessor-based architectures having, e. g., at least one signal processor or microprocessor. One skilled in the art would be able to program with suitable program code such a microcontroller-based, or microprocessor-based, implementation to perform the signal processing functionality disclosed herein without undue experimentation.

[0067] The scope of the invention is not intended to be limited to any particular implementation using technology either now known or later developed in the future. The scope of the invention is intended to include implementing the functionality of the signal processor(s) as stand-alone processor, signal processor, or signal processor module, as well as separate processor or processor modules, as well as some combination thereof.

[0068] By way of example, the apparatus 10 may also include, e.g., other signal processor circuits or components generally indicated 50, including random access memory or memory module (RAM) and/or read only memory (ROM), input/output devices and control, and data and address buses connecting the same, and/or at least one input processor and at least one output processor, e.g., which would be appreciate by one skilled in the art.

[0069] By way of further example, the signal processor may include, or take the form of, some combination of a signal processor and at least one memory including a computer program code, where the signal processor and at least one memory are configured to cause the system to implement the functionality of the present invention, e.g., to respond to signaling received and to determine the corresponding signaling, based upon the signaling received.

FIGS. 6A and 6B: The 3D Cylindrical Linear Sensor Array 60

[0070] By way of example, the apparatus 10 may include a closed cylinder sensor array 60 having a three-dimensional cylindrical array of the rows and columns of the optical elements and a length L, e.g., as shown in FIG. 6A.

[0071] In FIG. 6A, the 3-D cylindrical linear sensor array 32 configured to capture light reflected off the suspended matter in the liquid along its length L and 360 degrees radially about its longitudinal axis.

[0072] As a person skilled in the art would appreciate, common/practical light sources including LEDs, laser diodes or broad-band lamps are often configured to provide a columnar or quasi-columnar optical radiation pattern for which the ideal photosensitive area takes the shape of a long, cylindrical shell, capturing rays perpendicular to the excitation column. According to the inventor at the time of this patent application filing, there are no commercially available “closed-cylinder” sensor arrays.

Inner Filter Effect (IFE)

[0073] As a person skilled in the art would appreciate, the IFE is a fluorescence spectroscopy phenomenon, e.g., where there is a decrease in fluorescence emission seen in concentrated solutions due to the absorption of exciting light by the fluorophore that is close to the incident beam and which significantly diminishes light that reaches the sample further away from it.

[0074] As a person skilled in the art would appreciate, techniques for correcting for the IFE are known in the art, and the scope of the invention is not intended to be limited to any particular type or kind thereof either now known or later developed in the future.

Applications

[0075] The present invention has applications, e.g., in the basic parameter of water quality monitoring for freshwater applications (e.g., where turbidity is one of the “big five”), as well as drinking water monitoring.

THE SCOPE OF THE INVENTION

[0076] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed herein as the best mode contemplated for carrying out this invention.