Systems and methods of determining a quality and a quantity of a fluid

1. A system for determining a quality and a quantity of a fluid in a tank having a bottom, the system comprising:

a fixed object;

a first transducer configured to generate a first sound wave in a horizontal direction and to detect a first echo of the first sound wave from the fixed object, the first transducer configured to be positioned near the bottom of the tank, and the fixed object positioned a known distance away from the transducer;

a second transducer configured to generate a second sound wave in a vertical direction and to detect a second echo of the second sound wave, the second transducer configured to be positioned near the bottom of the tank such that the second sound wave travels toward a surface of the fluid in the tank;

a temperature sensor configured to detect a temperature of the fluid; and

a controller configured to:

produce a first signal to drive the first transducer to produce the first sound wave,

produce a second signal to drive the second transducer to produce the second sound wave,

receive a first indication of the detected first echo from the first transducer,

receive a second indication of the detected second echo from the second transducer,

receive a temperature indication of the fluid from the temperature sensor,

determine a quality of the fluid based on the first indication and the temperature indication, and

determine a quantity of the fluid based on the second indication.

2. The system of claim 1 , wherein the controller is further configured to determine whether a contaminant exists in the fluid based on whether a dilution of the fluid is detected while a measured volume of the fluid decreases.

3. The system of claim 1 , wherein the first transducer and the second transducer produce an ultrasonic sound wave.

4. The system of claim 1 , wherein the controller determines that the detected first echo is valid when the detected first echo is received by the first transducer within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

5. The system of claim 1 , wherein the controller determines that the detected second is valid when the detected second echo is received by the second transducer within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

6. The system of claim 1 , wherein the fluid is a urea solution.

7. The system of claim 1 , wherein the controller determines a speed of sound of the fluid based on the first indication and the temperature indication.

8. The system of claim 1 , wherein determining the quality of the fluid includes determining a concentration of the fluid.

9. The system of claim 1 , wherein determining the quantity of the fluid includes determining a level of the fluid.

10. A sensing system for sensing a fluid in a tank, the system comprising:

a sensor housing;

a fixed target;

a first transducer configured to generate a first sound wave and to detect a first echo of the first sound wave from the fixed target, the first transducer positioned near the bottom of the tank, the fixed object positioned a known distance away from the transducer;

a second transducer configured to generate a second sound wave and to detect a second echo of the second sound wave, the second transducer positioned to direct the second sound wave toward a surface of the fluid in the tank;

a temperature sensor configured to detect a temperature of the fluid; and

a controller configured to:

produce a first signal to drive the first transducer to produce the first sound wave,

produce a second signal to drive the second transducer to produce the second sound wave,

receive a first indication of the detected first echo from the first transducer,

receive a second indication of the detected second echo from the second transducer,

receive a temperature indication of the temperature of the fluid from the temperature sensor,

determine a quality of the fluid based on the first indication and the temperature indication, and

determine a quantity of the fluid based on the second indication, and the temperature indication.

11. The system of claim 10 , wherein the controller is further configured to determine whether a contaminant exists in the fluid based on whether a dilution of the fluid is detected while a measured volume of the fluid decreases.

12. The system of claim 10 , wherein the first transducer and the second transducer produce an ultrasonic sound wave.

13. The system of claim 10 , wherein the controller determines that the detected first echo is valid when the detected first echo is received by the first transducer within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

14. The system of claim 10 , wherein the controller determines that the detected second echo is valid when the detected second echo is received by the second transducer within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

15. The system of claim 10 , wherein the fluid is a urea solution.

16. The system of claim 10 , wherein the controller determines a speed of sound of the fluid based on the first indication and the temperature indication.

17. The system of claim 10 , wherein determining the quality of the fluid includes determining a concentration of the fluid.

18. The system of claim 10 , wherein determining the quantity of the fluid includes determining a level of the fluid.

19. A method of sensing a fluid in a tank, the method comprising:

generating a first sound wave in a horizontal direction;

detecting an echo of the first sound wave from a fixed object positioned at a known location;

generating a second sound wave in a vertical direction such that the second sound wave travels toward a surface of the fluid in the tank;

detecting an echo of the second sound wave;

detecting a temperature of the fluid;

determining a quality of the fluid based on the echo of the first sound wave and the temperature; and

determining a quantity of the fluid based on the echo of the second sound wave, and the temperature.

20. The method of claim 19 , further comprising determining whether a contaminant exists in the fluid based on whether a dilution of the fluid is detected while a measured volume of the fluid decreases.

21. The method of claim 19 , further comprising determining that the echo of the first sound wave is valid when the echo of the first sound wave is received within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

22. The method of claim 19 , further comprising determining that the echo of the second sound wave is valid when the echo of the second sound wave is received within a predetermined time limit, has an amplitude that falls within a predetermined range, has a duration within a predetermined time range, or a combination of the foregoing.

23. The method of claim 19 , wherein the fluid is a urea solution.

24. The method of claim 19 , further comprising determining a speed of sound of the fluid based on the echo of the first sound wave and the temperature.

25. The system of claim 19 , wherein determining the quality of the fluid includes determining a concentration of the fluid.

26. The system of claim 19 , wherein determining the quantity of the fluid includes determining a level of the fluid.