Methods for determining transducer delay time and transducer separation in ultrasonic flow meters

• US 7,152,490 B1
• Filed: 08/15/2005
• Issued: 12/26/2006
• Est. Priority Date: 08/15/2005
• Status: Active Grant

• Current Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Original Assignee: Daniel Measurement and Control Incorporated (Emerson Electric Company)
• Inventors: Zanker, Klaus J., Freund, William R. Jr.
• Primary Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US11/204,068
• Time in Patent Office: 498 Days
• Field of Search: 738/612.9, 738/612.7, 738/611.8, 738/611.9, 738/612.5, 738/612.6
• US Class Current: 73/861.27
• CPC Class Codes: G01F 1/667 Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters
• CPC Class Codes: G01F 1/668 Compensating or correcting for variations in velocity of sound

Abstract

Methods and related systems for determining transducer delay time and transducer separation in ultrasonic flow meters. At least some of the illustrative embodiments are a method comprising measuring a delay time for a first transducer pair, measuring a total measured time for ultrasonic signals transmitted between a second transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed, calculating a parameter associated with the second transducer pair using the delay time of the first transducer pair and the total measured time for said second transducer pair.

Claims

1. A method comprising:

measuring a delay time for a first transducer pair;

measuring a total measured time for ultrasonic signals transmitted between a second transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed; and

calculating a parameter associated with the second transducer pair using the delay time of the first transducer pair and the total measured time for said second transducer pair.

2. The method as defined in claim 1 wherein measuring the delay time further comprises determining delay time at infinite separation of first transducer pair.

3. The method as defined in claim 2 wherein calculating further comprises calculating the parameter using delay time at infinite separation of the first transducer pair.

4. The method as defined in claim 1 wherein calculating further comprises calculating a delay time for the second transducer pair.

5. The method as defined in claim 1 wherein calculating further comprises calculating a delay time error of the delay time for the second transducer pair.

6. The method as defined in claim 1 wherein calculating further comprises calculating a distance between the second transducer pair.

7. The method as defined in claim 1 wherein calculating further comprises calculating a distance error between the second transducer pair.

8. The method as defined in claim 1 wherein calculating further comprises calculating the parameter using the delay time of the first transducer pair and a time associated with the second transducer pair at least partially compensated for differences between total measured time and actual transit time.

9. The method as defined in claim 1 wherein measuring the delay time for first transducer pair further comprises measuring the delay time for the first transducer pair with the first transducer pair in a test cell.

10. A method comprising

measuring a delay time difference between a first pair of transducers and a second pair of transducers;

measuring a first total measured time for ultrasonic signals transmitted between the first transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed;

measuring a second total measured time for ultrasonic signals transmitted between the second transducer pair in the ultrasonic meter; and

calculating a delay time for the first transducer pair using the delay time difference and the total measured times.

11. The method as defined in claim 10 further comprising calculating a delay time for the second transducer pair using the delay time difference and the total measured times.

12. The method as defined in claim 10 wherein measuring a delay time difference further comprises measuring the delay time difference in a test cell.

13. The method as defined in claim 10 wherein calculating the delay time further comprises calculating the delay time for the first transducer pair using the delay time difference and times at least partially compensated for differences between total measured time and actual transit time.

14. An ultrasonic meter comprising:

a spool piece which fluidly couples within a conduit carrying fluid flow;

control electronics associated with the spool piece;

a first chord through the spool piece, the first chord accepts a first pair of transducers, and the control electronics couple to the first pair of transducers; and

a second chord through the spool piece, the second chord accepts a second pair of transducers, and the control electronics couple to the second pair of transducers;

wherein the control electronics accept a value proportional to a delay time for the first pair of transducers, and wherein the control electronics calculate a parameter associated with the second pair of transducers using at least the value proportional to the delay time for the first pair of transducers.

15. The ultrasonic meter as defined in claim 14 wherein the control electronics accept the value proportional to the delay time being the delay time at infinite separation.

16. The ultrasonic meter as defined in claim 14 wherein the control electronics calculate a delay time for the second transducer pair.

17. The ultrasonic meter as defined in claim 14 wherein the control electronics are configured to calculate a delay time error of the delay time for the second transducer pair.

18. The ultrasonic meter as defined in claim 14 wherein the control electronics are configured to calculate a distance between the second transducer pair.

19. The ultrasonic meter as defined in claim 14 wherein the control electronics are configured to calculate a distance error between the second transducer pair.

20. The ultrasonic meter as defined in claim 14 wherein the control electronics are configured to calculate a parameter using the delay time of the first transducer pair and a time associated with the second transducer pair at least partially compensated for differences between total measured time and actual transit time.