System and Method for Sensing Ammonia

• US 20140311350A1
• Filed: 01/13/2014
• Published: 10/23/2014
• Est. Priority Date: 01/11/2013
• Status: Active Grant

• Current Assignee: Lumense, Inc.
• Original Assignee: Lumense, Inc.
• Inventors: Caspall, Jayme, Campbell, Daniel, Cobb-Sullivan, Janet, Bobzin, Bonnie, Johnson, Kenneth, Jones, Robert E., Slawson, Michael
• Granted Patent: US 9,644,940 B2
• Time in Patent Office: Days
• US Class Current: 96/417
• CPC Class Codes: A01K 31/00 Housing birds
• CPC Class Codes: B01D 29/60 integrally combined with devices for controlling the filtration
• CPC Class Codes: B01D 46/46 automatic
• CPC Class Codes: G01B 9/02015 characterised by the beam path configuration
• CPC Class Codes: G01N 2021/458 using interferential sensor, e.g. sensor fibre, possibly on optical waveguide
• CPC Class Codes: G01N 2021/7779 interferometric
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G01N 33/0054 Ammonia
• CPC Class Codes: G01N 33/0063 using a threshold to release an alarm or displaying means
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

A system and method for the monitoring of ammonia in a fluid. The ammonia monitoring system includes an ammonia sensor that is configured to detect trace amounts of ammonia (NH₃) in a fluid (i.e., gas or liquid) that is pumped through it in real time. The real time ammonia sensor includes an interferometer configured to track the amount of ammonia that is pumped into the real time ammonia sensor. The ammonia monitoring system, via the real time ammonia sensor, is further configured to detect ammonia levels in industrial poultry houses and provide electronic feedback to the building'"'"'s ventilation control system.

Claims

1. An automated ammonia monitoring system, comprising:

a. A chemical sensor module comprising an interferometer configured to track the amount of ammonia in a fluid;

b. a fluid control system for supplying a representative flow of the fluid to the interferometer; and

c. a control system to selectively remove ammonia from the fluid responsive to a detection of a threshold amount of ammonia by the interferometer.

2. The automated ammonia monitoring system of claim 1, wherein the interferometer further comprises a waveguide, wherein the fluid control system provides the representative flow of the fluid to the waveguide to track the amount of ammonia the fluid.

3. The automated ammonia monitoring system of claim 2, wherein the waveguide further comprises at least one sense channel and at least one reference channel.

4. The automated ammonia monitoring system of claim 3, wherein the at least one sense channel is coated with a polymer that adsorbs ammonia.

5. The automated ammonia monitoring system of claim 4, wherein the at least one reference channel is coated with a non-ammonia-absorptive polymer, wherein the interferometer is configured to detect the ammonia through the use of an interference pattern created by a laser passing light through the at least one sense channel and the at least one reference channel.

6. The automated ammonia monitoring system of claim 5, wherein the interferometer further comprises a camera configured to capture the interference pattern.

7. The automated ammonia monitoring system of claim 6, further comprising a monitor controller, wherein the monitor controller is configured to determine an ammonia concentration of the representative flow of the fluid from the captured interference pattern.

8. The automated ammonia monitoring system of claim 7, wherein the monitor controller comprises a processor and a system memory, wherein the processor is configured to determine the ammonia concentration of the representative flow of the fluid by determining a phase shift of the captured interference pattern.

9. The automated ammonia monitoring system of claim 8, wherein the processor is configured to determine the phase shift of the captured interference pattern by determining an appropriate measurement zone of the captured interference pattern, determining an interference pattern period within the appropriate measurement zone, determining the phase shift that has occurred from the interference pattern period, and correlating data from the phase shift with calibration data to obtain the ammonia concentration.

10. The automated ammonia monitoring system of claim 4, wherein the polymer coating the at least one sense channel comprises polyvinylphenol.

11. The automated ammonia monitoring system of claim 4, wherein the chemical sensor module and the fluid control system are configured to expose the waveguide to the representative flow of the fluid, wherein the representative flow of the fluid comprises ammonia-filtered fluid and unfiltered fluid.

12. The automated ammonia monitoring system of claim 1, wherein the chemical sensor module is configured to self-calibrate.

13. The automated ammonia monitoring system of claim 1, wherein the fluid control system is further configured to regulate temperature of the representative flow of the fluid.

14. An automated system for monitoring the amount of ammonia in a fluid comprising:

a. a chemical sensor module configured to track the amount of ammonia in a representative flow of the fluid, the chemical sensor module comprising;

i. an interferometer comprising;

A. a laser;

B. a camera; and

C. a waveguide, wherein the waveguide is oriented within a flow cell, wherein the waveguide comprises;

I. a sense channel covered in an ammonia adsorptive polymer; and

II. a reference channel covered in a non-ammonia adsorptive polymer, wherein the laser is configured to pass light through the sense channel and the reference channel as the representative flow of the fluid passes through the flow cell and the sense channel and reference channel to create an interference pattern captured by the camera in images;

b. a fluid control system for supplying the representative flow of the fluid, the fluid control system comprising;

i. at least one intake hose configured to intake the representative flow of the fluid;

ii. a pump configured to pump the representative flow of the fluid;

iii. a filtered path in communication with the at least one intake hose;

iv. an unfiltered path in communication with the at least one intake hose; and

iv. a valve configured to switch the representative flow of the fluid from the filtered path and the unfiltered path to provide ammonia filtered representative fluid and non-ammonia filtered representative fluid to the chemical sensor module via the flow cell; and

c. a monitor controller configured to control the fluid control system and the chemical sensor module in order to determine a concentration of ammonia in the representative flow of the fluid, the monitor controller comprising;

i. a processor; and

ii. system memory, wherein the processor determines the concentration of ammonia in the representative fluid by;

A. determining an appropriate measurement zone of the images from the camera;

B. determining an interference pattern period within the measurement zone;

C. determining a phase shift from the interference pattern period;

D. correlating data from the phase shift with calibration data to obtain an ammonia concentration reading; and

E. processing the ammonia concentration reading to eliminate noise and other potential faulty data to determine the ammonia concentration reading, wherein the automated ammonia monitoring system is further configured to communicate with a control system to selectively remove ammonia from the fluid responsive to the detection of the ammonia when notified by the monitor controller that the ammonia concentration reading is above an ammonia threshold.

15. A interferometry-centered method for determining a concentration of ammonia in a fluid, the method comprising:

a. exposing a waveguide to the fluid, wherein the waveguide comprises a sense channel coated with an ammonia adsorptive polymer and a reference channel coated with a non-ammonia adsorptive polymer;

b. forming an interference pattern with the waveguide as the waveguide is exposed to the fluid; and

c. determining the concentration of ammonia from the interference pattern.

16. The method of claim 15, wherein determining the concentration of ammonia from the interference pattern further comprises:

i. determining an appropriate measurement zone of an image of the interference pattern;

ii. determining an interference pattern period within the appropriate measurement zone;

iii. determining a phase shift that has occurred from the interference pattern period; and

iv. correlating data from the phase shift with calibration data to obtain the concentration of ammonia.

17. The method of claim 16, further comprising the step of processing the concentration of ammonia to eliminate noise and faulty data after correlating the data from the phase shift with the calibration data.

18. The method of claim 16, wherein determining the interference pattern period within the appropriate measurement zone further comprises utilizing image processing algorithms to determine the interference pattern period.

19. The method of claim 18, wherein utilizing image processing algorithms to determine the interference pattern period further comprises utilizing a spatial Fourier transform algorithm to generate a dominant spatial frequency of the interference pattern.

20. The method of claim 19, wherein determining the data from the phase shift from the interference pattern period comprises using a phase demodulation with the dominant spatial frequency to determine the data from the phase shift.

21. The method of claim 15, wherein exposing the waveguide to the fluid further comprises exposing the waveguide to ammonia filtered fluid after the waveguide has been exposed to unfiltered fluid.