TEMPERATURE COMPENSATION OF A TEST TONE USED IN METER VERIFICATION

• US 20190316944A1
• Filed: 11/30/2016
• Published: 10/17/2019
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Original Assignee: Micro Motion Incorporated (Emerson Electric Company)
• Inventors: KEENEY-RITCHIE, Miles
• Granted Patent: US 11,067,423 B2
• Time in Patent Office: Days
• CPC Class Codes: G01F 1/8422 exciters
• CPC Class Codes: G01F 1/8431 electronic circuits
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 15/024 involving digital counting
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01R 19/04 Measuring peak values or amplitude or envelope of ac or of pulses
• CPC Class Codes: G01R 19/32 Compensating for temperature change
• CPC Class Codes: H03F 2200/468 the temperature being sensed
• CPC Class Codes: H03L 1/02 against variations of temperature only
• CPC Class Codes: H03L 1/026 by using a memory for digitally storing correction values H03L1/025 takes precedence
• CPC Class Codes: H03L 1/028 of generators comprising piezoelectric resonators H03L1/021, H03L1/022 take precedence; oscillation generators with a piezoelectric resonator H03B5/32

Abstract

A method for temperature compensation of a test tone used in meter verification is provided. The method uses a drive amplifier to provide a drive signal to a drive circuit, wherein the drive circuit includes a drive mechanism in a meter assembly of a vibratory meter. The method measures a first maximum amplitude of the drive signal at a first temperature of the drive circuit, and measures a second maximum amplitude of the drive signal at a second temperature of the drive circuit. The method also determines a maximum amplitude-to-temperature relationship for the drive circuit based on the first maximum amplitude at the first temperature and the second maximum amplitude at the second temperature.

Claims

1. A method for temperature compensation of a test tone used in meter verification, the method comprising:

using a drive amplifier to provide a drive signal to a drive circuit, wherein the drive circuit includes a drive mechanism in a meter assembly of a vibratory meter;

measuring a first maximum amplitude of the drive signal at a first temperature of the drive circuit;

measuring a second maximum amplitude of the drive signal at a second temperature of the drive circuit; and

determining a maximum amplitude-to-temperature relationship for the drive circuit based on the first maximum amplitude at the first temperature and the second maximum amplitude at the second temperature.

2. The method of claim 1, wherein the drive signal comprises a resonant drive signal and one or more test tones, the one or more test tones being at a frequency that is different than a frequency of the resonant drive signal.

3. The method of claim 2, wherein the first maximum amplitude is an amplitude of the one or more test tones and the second maximum amplitude is the amplitude of the one or more test tones.

4. The method of claim 1, wherein:

measuring the first maximum amplitude of the drive signal at the first temperature comprises increasing an amplitude of the drive signal at the first temperature until the amplitude of the drive signal is clipped and measuring an amplitude less than the amplitude at which the amplitude of the drive signal is clipped; and

measuring the second maximum amplitude of the drive signal at the second temperature comprises increasing the amplitude of the drive signal at the second temperature until the amplitude is clipped and measuring the amplitude of the drive signal that is less than the amplitude at which the amplitude of the drive signal is clipped.

5. The method of claim 1, wherein determining the maximum amplitude-to-temperature relationship for the drive circuit based on the first maximum amplitude at the first temperature and the second maximum amplitude at the second temperature comprises performing linear interpolation based on the first maximum amplitude at the first temperature and the second maximum amplitude at the second temperature.

6. The method of claim 1, wherein at least one of the first maximum amplitude and the second maximum amplitude comprises a maximum amplitude of a test tone in the drive signal.

7. A method for temperature compensation of a test tone used in meter verification, the method comprising:

determining a resistance-to-temperature relationship of a drive circuit configured to receive a drive signal from a drive amplifier, wherein the drive circuit includes a drive mechanism in a meter assembly of a vibratory meter;

determining a maximum output of the drive amplifier; and

determining a maximum amplitude of the drive signal based on the resistance-to-temperature relationship and the maximum output of the drive amplifier.

8. The method of claim 7, wherein determining the maximum amplitude of the drive signal based on the resistance-to-temperature relationship and the maximum output of the drive amplifier comprises determining a maximum amplitude-to-temperature relationship based on the resistance-to-temperature relationship and the maximum output of the drive amplifier.

9. The method of claim 7, wherein determining the resistance-to-temperature relationship of the drive circuit configured to receive the drive signal from the drive amplifier comprises determining a resistance of at least one of a drive resistor, a drive mechanism, and a lead between the drive amplifier and the drive mechanism.

10. The method of claim 7, wherein determining the maximum amplitude of the drive signal based on the resistance-to-temperature relationship and the maximum output of the drive amplifier comprises measuring a temperature of the drive circuit and determining a resistance of the drive circuit based on the measured temperature and the resistance-to-temperature relationship and calculating the maximum amplitude of the drive signal based on the determined resistance of the drive circuit at the measured temperature.

11. The method of claim 7, wherein the resistance-to-temperature relationship comprises linear relationship between a temperature of the drive circuit and a resistance of the drive circuit.

12. The method of claim 7, wherein the maximum amplitude of the drive signal comprises a maximum amplitude of a test tone in the drive signal.

13. A method for temperature compensation of a test tone used in meter verification, the method comprising:

measuring a temperature of a drive circuit configured to receive a drive signal from a drive amplifier, wherein the drive circuit includes a drive mechanism in a meter assembly of a vibratory meter;

obtaining a maximum amplitude-to-temperature relationship;

determining a maximum amplitude based on the measured temperature of the drive circuit and the maximum amplitude-to-temperature relationship; and

setting a maximum amplitude of the drive signal provided by the drive amplitude to the determined maximum amplitude.

14. The method of claim 13, wherein obtaining the maximum amplitude-to-temperature relationship comprises determining a maximum amplitude-to-temperature relationship for the drive circuit based on a first maximum amplitude of the drive signal at a first temperature and a second maximum amplitude of the drive signal at a second temperature.

15. The method of claim 13, wherein determining the maximum amplitude based on the measured temperature of the drive circuit and the maximum amplitude-to-temperature relationship comprises determining a resistance of the drive circuit at the measured temperature and determining the maximum amplitude based on the determined resistance of the drive circuit at the measured temperature.

16. The method of claim 13, wherein determining the maximum amplitude based on the measured temperature of the drive circuit and the maximum amplitude-to-temperature relationship comprises determining a maximum amplitude of at least one test tone in the drive signal.

17. The method of claim 13, wherein setting the maximum amplitude of the drive signal comprises setting a maximum amplitude of a test tone in the drive signal.

18. The method of claim 13, wherein setting the maximum amplitude of the drive signal comprises writing a value to at least one of a processor and a memory in a meter electronics that provides the drive signal to the drive mechanism.