Dispense Verification Meters

• US 20090171502A1
• Filed: 12/28/2007
• Published: 07/02/2009
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Malema Engineering Corporation (Dover Corporation)
• Original Assignee: Malema Engineering Corporation (Dover Corporation)
• Inventors: Freidin, Philip M.
• Granted Patent: US 8,185,237 B2
• Time in Patent Office: Days
• US Class Current: 700/240
• CPC Class Codes: G01F 13/006 measuring volume in function of time
• CPC Class Codes: G01F 25/0084 for measuring volume
• CPC Class Codes: G01F 9/008 where the other variable is the flight or running time

Abstract

A dispense verification meter for measuring and verifying dispense operations (e.g., actual dispensed volumes) of media dispense systems. The dispense verification meter preferably automatically corrects zero offset drift, preferably samples the flow rate of media being dispensed at a sufficiently high sample rate, and verifies whether the desired dispense operation has been achieved.

Claims

1. A method for a dispense verification meter to verify a dispense operation, the method comprising the dispense verification meter taking the following steps:

receiving a descriptor for a desired dispense operation;

responsive to a trigger signal indicating an occurrence of a dispense operation, measuring flow rates of a media to be dispensed multiple times over the course of the dispense operation;

calculating a dispensed volume of the media based on the multiple flow rate measurements; and

verifying the dispense operation based on the calculated dispensed volume and the received descriptor.

2. The method of claim 1, wherein the trigger signal indicates that dispense of the media will start after a predetermined delay.

3. The method of claim 1, wherein measuring flow rates of the media over the course of the dispense operation further comprises taking flow rate measurements at a frequency that is higher than a sampling frequency of the dispense operation.

4. The method of claim 1, wherein:

the descriptor for the desired dispense operation includes a minimum dispensed volume and a maximum dispensed volume; and

verifying the dispense operation comprises determining whether the calculated dispensed volume is between the minimum dispensed volume and the maximum dispensed volume, and if the calculated volume is not between the minimum dispensed volume and the maximum dispensed volume, issuing an alarm signal indicating a failed verification.

5. The method of claim 1, further comprising:

transmitting a verification result indicating either a successful or a failed verification.

6. The method of claim 1, further comprising:

adjusting a subsequent dispense operation, based on the calculated dispensed volume compared to the received descriptor for the desired dispense operation.

7. The method of claim 1, further comprising:

adjusting a subsequent dispense operation, based on the success or failure of the verification.

8. The method of claim 1, further comprising:

measuring an idle flow rate of the media one or more times during an idle period between dispense operations, wherein calculating the dispense volume of the media based on the multiple flow rate measurements further comprising calculating the dispensed volume of the media based on the multiple flow rate measurements and the idle flow rate measurement(s).

9. The method of claim 1, wherein calculating the dispensed volume of the media further comprises:

calculating a zero offset drift based on the idle flow rate measurement(s); and

numerically integrating the multiple flow rate measurements, taking into account the calculated zero offset drift.

10. The method of claim 9, wherein numerically integrating the multiple flow rate measurements, taking into account the calculated zero offset drift comprises:

for each flow rate measurement taken over the course of the dispense operation, calculating an adjusted flow rate measurement by offsetting the zero offset drift; and

numerically integrating the multiple adjusted flow rate measurements.

11. The method of claim 9, wherein calculating the zero offset drift comprises:

measuring the idle flow rate multiple times during the idle period; and

calculating the zero offset drift based on an average of the idle flow rate measurements.

12. The method of claim 11, wherein the average of the idle flow rate measurements is an average of idle flow rates measured since the end of the immediately previous dispense operation.

13. The method of claim 11, wherein measuring the idle flow rate multiple times comprises measuring the idle flow rate multiple times after receiving the trigger signal but before starting dispense of the media.

14. The method of claim 8, wherein the trigger signal indicates that dispense of the media will start after a predetermined delay.

15. The method of claim 8, wherein measuring flow rates of the media over the course of the dispense operation further comprises taking flow rate measurements at a frequency that is higher than a sampling frequency of the dispense operation.

16. The method of claim 8, wherein:

the descriptor for a desired dispense operation includes a minimum dispensed volume and a maximum dispensed volume; and

verifying the dispense operation comprises determining whether the calculated dispensed volume is between the minimum dispensed volume and the maximum dispensed volume, and if the calculated volume is not between the minimum dispensed volume and the maximum dispensed volume, issuing an alarm signal indicating a failed verification.

17. The method of claim 8, further comprising:

transmitting a verification result indicating either a successful or a failed verification.

18. The method of claim 8, further comprising:

adjusting a subsequent dispense operation, based on the calculated dispensed volume compared to the received descriptor for the desired dispense operation.

19. The method of claim 8, further comprising:

adjusting a subsequent dispense operation, based on the success or failure of the verification.

20. A dispense system, comprising:

a media dispense line;

a dispense pump connected to the media dispense line, the dispense pump pumping a media through the media dispense line;

a dispense verification meter connected to the media dispense line, the dispense verification meter receiving a descriptor for a desired dispense operation;

responsive to a trigger signal indicating an occurrence of a dispense operation, measuring flow rates of the media multiple times over the course of the dispense operation;

calculating a dispensed volume of the media based on the multiple flow rate measurements; and

verifying the dispense operation based on the calculated dispensed volume; and

a control system communicatively coupled to the dispense pump and the dispense verification meter, the control system receiving verification from the dispense verification meter, and also controlling the dispense pump.

21. The dispense system of claim 20, wherein the dispense verification meter measures an idle flow rate of the media, and wherein calculating the dispensed volume of the media based on the multiple flow rate measurements further comprises calculating the dispensed volume of the media based on the multiple flow rate measurements and the idle flow rate measurement(s).

22. The dispense system of claim 20, wherein the descriptor is sent by the control system or entered manually.

23. A dispense verification meter comprising:

a flowmeter that measure a flow rate of a media through a media dispense line to which the dispense verification meter is connected; and

an embedded controller communicatively coupled to the flowmeter, the embedded controller receiving a descriptor for a desired dispense operation;

responsive to a trigger signal indicating an occurrence of a dispense operation, controlling the flowmeter to measure flow rates of the media through the media dispense line multiple times over the course of a dispense operation;

calculating a dispensed volume of the media based on the multiple flow rate measurements; and

verifying the dispense operation based on the calculated dispensed volume and the received descriptor.

24. The dispense verification meter of claim 23, wherein the embedded controller controls the flowmeter to measure an idle flow rate of the media through the media dispense line, and wherein calculating the dispensed volume of the media based on the multiple flow rate measurements comprises calculating the dispensed volume of the media based on the multiple flow rate measurements and the idle flow rate measurement(s).

25. A computer program product for a dispense verification meter to verify a dispense operation, the computer program product comprising a computer-readable medium containing computer program code for performing a method comprising:

receiving a descriptor for a desired dispense operation;

responsive to a trigger signal indicating an occurrence of a dispense operation, measuring flow rates of a media to be dispensed multiple times over the course of the dispense operation;

calculating a dispensed volume of the media based on the multiple flow rate measurements; and

verifying the dispense operation based on the calculated dispensed volume and the received descriptor.

26. The computer program product of claim 25, wherein the method further comprises:

measuring an idle flow rate of the media one or more times during an idle period between dispense operations, wherein calculating the dispensed volume of the media based on the multiple flow rate measurements comprises calculating the dispensed volume of the media based on the multiple flow rate measurements and the idle flow rate measurement(s).