Linear analog sensor for in line measurement of the conductivity of beer and similar liquids

Abstract

A fluid conductivity test device for testing the conductivity of a fluid in a container. The device includes a fitting that may mate either directly to or indirectly to a tap on, for example, a keg, to allow the fluid in the container to come into contact with the sensor device. The conductivity of the fluid is measured and compared with known conductivities for identification of the fluid. The entire device is relatively small and light-weight for ease of connection to many different containers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is block diagram of one advantageous embodiment of the present invention.

FIG. 2 is an illustration of one advantageous embodiment of the fluid conductivity sensor according to FIG. 1.

FIG. 3 is a schematic diagram of one advantageous embodiment of the fluid conductivity sensor according to FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1-3, wherein like reference numerals designate corresponding structure throughout the views.

FIG. 1 is a block diagram depicting fluid conductivity sensor 10 coupled to fluid container 12. Fluid conductivity sensor 10 is directly coupled to fluid container 12 so that fluid comes directly into contact with fluid conductivity sensor 10.

The fluid conductivity sensor 10 is provided to measure the conductivity of any type of fluid; however, it is contemplated that the fluid may advantageously comprise spirits, such as for example, beer. In one embodiment, the conductivity sensor may be attached to a beer keg to detect and determine the type of beer connected to the beer tap. The conductivity sensor 10 may be placed directly in the line connecting the beer tap to the keg.

Also illustrated in FIG. 1 is measurement device display/power 14. Measurement device display/power 14 is illustrated as a dashed line to indicate that this is an optional feature. It is contemplated that virtually any type of display may be utilized; however, a relatively small, light-weight display such as, for example, an LCD may advantageously be utilized for local display of the fluid identification.

Referring to FIG. 2, one advantageous embodiment of the fluid conductivity sensor 10 is illustrated. In this illustration, fluid conductivity sensor 10 includes a housing 16, which may comprise, for example, a hard plastic such as polypropylene. Attached to an outer wall 18 of housing 16 is a fitting 20, which is designed to be attached inline with (e.g. directly or indirectly) a tap (not shown) of a fluid container 12. Tap 20 may be provided as, for example, a threaded connector designed to engage with, for example but not limited to, a ⅜ inch line or tubing such as is used with a keg.

Also illustrated in FIG. 2 is an input power connection 24, which provides input power for fluid conductivity sensor 10. It should be noted, however, that fluid conductivity sensor 10 may be provided with an internal power source, such as a rechargeable battery, eliminating the need for input power connection 24.

Still further illustrated is conductivity measurement signal connection 26, which provides a signal, related to the fluid conductivity measurement. Again, it should be noted that, while a hard-wired system is illustrated, it is contemplated that a wireless connection, such as for example, a wireless network connection, an infrared coupling or the like, may also be used for wirelessly transmitting information related to the fluid conductivity measurement as desired.

In addition, it is further contemplated that the sensor 10 may be provided with a network connection for transmitting the information related to the fluid conductivity measurement over a network. The network connection may comprise, for example, an internetwork connection, LAN, WAN and/or Internet connection and may be used to transmit the information to a local computer terminal or device or to a remote location.

Accordingly, a relatively light-weight portable device is provided that may easily be moved from one fluid container 12 to another for rapid determination and/or confirmation of the fluid in each container.

FIG. 3 is a schematic diagram of one advantageous embodiment of fluid conductivity sensor 10. The fluid conductivity sensor 10 is provided to measure the actual fluid conductivity and produce a 0-10 Volt output. The sensor 10 may be provided to output 10 V at the lowest conductivity measurement and 0 V at the highest conductivity measurement, however, the sensor may not actually go completely to zero volts.

It is contemplated that an identified set of conductivity values corresponding to a set of beverages may be obtained, where each beverage has a distinct conductivity value. Accordingly, an actual conductivity measurement may be made in Micro Seimans per CM, which is compared to the identified set of conductivity values. Once the actual measurement is match to an identified value, the fluid may be identified.

A number of potentiometers are illustrated in the schematic diagram including, P1 (power), P2 (trim), P3 (gain) and P4 (level). The four potentiometers are used to adjust the calibration of fluid conductivity sensor 10. Potentiometer P1 is used to set the span of the sensor. It is contemplated that the adjustable conductivity range of the sensor 10 is from approximately 100 to 5,000 Micro Siemans per CM. Potentiometers P2 and P4 are used to offset the DC 10X amplifier. Potentiometer P3 is used to set the zero or closest to zero level of the AC side of the sensor.

In one advantageous embodiment, the fluid conductivity sensor 10 may be set for 10 Volts to substantially equal 1,000 Micro Siemens and 2.9 Volts being 2,500 Micro Siemens.

The components illustrated in the schematic diagram of the fluid conductivity sensor 10 may, in one advantageous embodiment have the following values, identifications and/or part numbers:

TABLE 1
Diode D1     1N4004
Diode D2     1N4004
Diode D3     1N4004
Capacitor C1 330 μF
Capacitor C2 .1 μF
Capacitor C3 .01 μF
R3           2.0 MΩ
R4           220 KΩ
R19          2.0 KΩ
U1A          LM358D
U2           +12 V Regulator
P1 (Power)   100K Ohms
P2 (Trim)    10K Ohms
P3 (Gain)    20K Ohms
P4 (Level)   5M Ohms

It is further contemplated that conductivity range of the sensor 10 is provided as a circuit board mounted device that is positioned in an interior cavity of housing 16. In this manner, sensor 10 may be rapidly and easily manufactured and/or repaired by insertion and removal of the circuit board.

In addition, the circuit board may advantageously be provided as a sealed device such that the electronics are liquid-tight providing protection to the equipment and to any potential user(s).

While the sensor 10 has been described in one advantageous embodiment (FIG. 3) by the interconnection of a number of discrete electronic components, it is contemplated that the sensor 10 may comprise a programmable microprocessor or a logic array or a combination thereof of software, hardware and/or firmware to achieve the same or similar results. In any event, the sensor 10 will advantageously be attachable directly to the tap line for a direct conductivity measurement of the fluid such that the identity of the fluid can be determined. The sensor 10 provides a variable voltage output corresponding to the measured conductivity, which may be compared to a table of know conductivities for identified beverages, the output voltage corresponding to a particular beverage. It is contemplated that the step of comparing the output voltage with a table of known beverages may be performed either locally within the sensor 10 for local display or may be performed by a processor for either local and/or remote display.

In this manner, a user may quickly and easily determine the identity of a fluid in a container by rapid, simple conductivity test instrument that may be attached directly to the tap.

Although the invention has been described with reference to a particular arrangement of parts, features and the like, these are not intended to exhaust all possible arrangements or features, and indeed many other modifications and variations will be ascertainable to those of skill in the art.

Claims

1. A device for identifying a fluid in a container comprising: a housing defining an interior cavity and having at least one exterior wall;a conductivity sensor positioned within the interior cavity;at least one fitting positioned on the at least one exterior wall;said at least one fitting attachable inline with a tap on the container such that the fluid in the container is passed to said conductivity sensor;a set of conductivity values corresponding to an identified set of beverages, where each beverage has a distinct conductivity value;said conductivity sensor measuring the conductivity of the fluid to generate an actual conductivity measurement; andsaid fluid identified based on the actual conductivity measurement and said set of conductivity values.

2. The device according to claim 1 where said conductivity sensor comprises at least one potentiometer that calibrates the said conductivity sensor.

3. The device according to claim 2 wherein said potentiometer is adjustable to calibrate said conductivity sensor to produce approximately a 0 to 10 volt output.

4. The device according to claim 2 wherein said at least one potentiometer comprises at least two potentiometers, the first potentiometer setting the span of the sensor and the second potentiometer setting the zero or closest to zero level of an AC side of the conductivity sensor.

5. The device according to claim 4 wherein said at least two potentiometers comprises at least four potentiometers, the third and the fourth potentiometers setting the offset of a DC amplifier.

6. The device according to claim 1 wherein said conductivity sensor is circuit board mounted within the interior cavity.

7. The device according to claim 6 wherein the circuit board is sealed to be liquid-tight.

8. The device according to claim 1 wherein the actual conductivity measurement is measured in Micro Siemens per CM.

9. The device according to claim 8 wherein said conductivity sensor has a range that is adjustable from approximately 100 to approximately 5,000 Micro Siemens per CM.

10. The device according to claim 1 further comprising a display for displaying information related to the identification of the fluid.

11. The device according to claim 1 further comprising an electrical connection for providing electrical power to said conductivity sensor.

12. The device according to claim 1 further comprising a data connection for transmitting information relating to the identification of the fluid.

13. The device according to claim 1 wherein said at least one fitting comprises a fitting directly attachable to a ⅜ inch line.

14. The device according to claim 13 wherein said fitting is a threaded fitting.

15. The device according to claim 1 wherein said housing comprises polypropylene.

16. A method for identifying a fluid in a container comprising the steps of: positioning a conductivity sensor in a housing;positioning at least one fitting on an exterior wall of the housing;attaching the at least one fitting inline with a tap on the container;passing fluid from the container to the conductivity sensor through the at least one fitting;measuring the conductivity of the fluid;comparing the measured conductivity of the fluid to a set of conductivity values; anddetermining the identity of the fluid by matching the measured conductivity to one of the conductivity values in the set of conductivity values.

17. The method according to claim 16 further comprising the step of adjusting a potentiometer to calibrate the conductivity sensor.

18. The method according to claim 16 further comprising the step of displaying the identity of the fluid to a user.

19. A device for identifying a fluid in a container comprising: a housing having a circuit board conductivity sensor positioned therein, said sensor sealed to prevent fluid from affecting the operation of the sensor;a fluid fitting affixed to an exterior of the housing, said fitting attachable inline with a tap on the container such that fluid is passed from the interior of the container to the sensor;a conductivity measurement of the fluid impinging on the sensor;a set of conductivity values corresponding to an identified set of beverages, each beverage having a different conductivity value;said fluid identified and/or differentiated based on a comparison of the actual conductivity measurement to said set of conductivity values; anda display providing a user with the fluid identification and/or differentiation.