Method for measuring material level in a container using RFID tags

• US 20060132351A1
• Filed: 12/16/2004
• Published: 06/22/2006
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Kyndryl Incorporated
• Original Assignee: International Business Machines Corporation
• Inventors: Le Sesne, Richard H.
• Granted Patent: US 7,113,125 B2
• Time in Patent Office: Days
• US Class Current: 342/124
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: G01F 23/2845 for discrete levels G01F23/288, G01F23/292 take precedence

Abstract

A level of liquid of pulverent solids in a container (or volume of a liquid in the absence of gravity) is detected by using radio frequency identification (RFID) tags or similar transponders located inside or outside the container. The interrogation signal and/or the return signal is attenuated by the material and the signal strength of the return signal, if any, is evaluated either directed or in a binary fashion by imposing a threshold to determine whether or not material in contained in a portion of the container corresponding to the location of a particular RFID tag or transponder. Volume, pressure and container orientation can also be derived in accordance with one or more return signals.

Claims

1. An apparatus for measurement of a level within a container of a material capable of attenuating radio frequency energy, said apparatus comprising

a radio transponder at a known location relative to said container, and

an interrogation transmitter/receiver capable of transmitting a radio frequency signal to said radio transponder across a portion of said container capable of containing said material and evaluating a return signal to determine presence of said material in said portion of said container.

2. An apparatus as recited in claim 1, wherein said transponder is a radio frequency identification (RFID) tag located within said container.

3. An apparatus as recited in claim 2, wherein said RFID tag is supported in said container by a sleeve.

4. An apparatus as recited in claim 3, further including a plurality of RFID tags in a spaced array.

5. An apparatus as recited in claim 4, wherein said spaced array of said plurality of RFID tags is linear.

6. An apparatus as recited in claim 4, wherein said spaced array of said plurality of RFID tags is arcuate.

7. An apparatus as recited in claim 4, wherein said spaced array of said plurality of RFID tags extends in at least two directions.

8. An apparatus as recited in claim 4, wherein spacing of said RFID tags in said spaced array is equal.

9. An apparatus as recited in claim 1, including another RFID tag located in proximity to said RFID tag, said RFID tag and said second RFID tag defining a level of interest.

10. An apparatus as recited in claim 1, including another RFID tag, said RFID tag and said another RFID tag defining a container orientation of interest.

11. An apparatus as recited in claim 1, further including RF opaque material applied to one of said RFID tag and said interrogation transmitter/receiver to define a communication path therebetween.

12. An apparatus as recited in claim 1, further including a delay arrangement to control measurement repetition frequency.

13. An apparatus as recited in claim 1, further including a memory accessible in accordance with an identification of said RFID tag.

14. An apparatus as recited in claim 12, wherein said memory stores at least one of level information, volume information, container identification information and pressure information.

15. A method for measuring material level in a container, said material being capable of attenuating a signal passing therethrough, said method comprising steps of

transmitting a signal through a portion of a container to a transponder, said portion of said container being capable of containing said material, and

detecting said material in said portion of said container based on a return signal returned from said transponder.

16. A method as recited in claim 15, including a further step of

determining a volume of material in said container based on said signal returned from said transponder.

17. A method as recited in claim 15, including a further step of

determining an orientation of said container based on said signal returned from said transponder.

18. A method as recited in claim 15, including a further step of

determining an identification of said container based on said signal returned from said transponder.

19. A method as recited in claim 15, including a further step of collimating one of said signal and said return signal.

20. A method as recited in claim 15, including a further step of controlling repetition frequency of said transmitting and detecting steps.