Vibratory flowmeter and method for meter verification

1. A vibratory flowmeter ( 5 ) for meter verification, the vibratory flowmeter ( 5 ) comprising:

a flowmeter assembly ( 10 ) including one or more flowtubes ( 130 , 130 ′) and first and second pickoff sensors ( 170 L, 170 R);

first and second drivers ( 180 L, 180 R) configured to vibrate the one or more flowtubes ( 130 , 130 ′); and

meter electronics ( 20 ) coupled to the first and second pickoff sensors ( 170 L, 170 R) and coupled to the first and second drivers ( 180 L, 180 R), with the meter electronics ( 20 ) being configured to vibrate the flowmeter assembly ( 10 ) in a primary vibration mode using the first and second drivers ( 180 L, 180 R), determine first and second primary mode currents ( 230 ) of the first and second drivers ( 180 L, 180 R) for the primary vibration mode, determine first and second primary mode response voltages ( 231 ) generated by the first and second pickoff sensors ( 170 L, 170 R) for the primary vibration mode, and generate a meter stiffness value ( 216 ) using the first and second primary mode currents ( 230 ) and the first and second primary mode response voltages ( 231 ), the meter stiffness value being a 2×2 matrix including a cross stiffness term K LR and a cross stiffness term K RL , wherein the primary vibration mode is a natural vibration mode of the one or more flow tubes.

2. The vibratory flowmeter ( 5 ) of claim 1 , with the first and second primary mode currents ( 230 ) comprising commanded current levels.

3. The vibratory flowmeter ( 5 ) of claim 1 , with the first and second primary mode currents ( 230 ) comprising measured current levels.

4. The vibratory flowmeter ( 5 ) of claim 1 , wherein the second driver ( 180 R) is uncorrelated with the first driver ( 180 L).

5. The vibratory flowmeter ( 5 ) of claim 1 , with the meter electronics ( 20 ) being further configured to compare the meter stiffness value ( 216 ) to a predetermined stiffness range ( 219 ), generate a verification indication for the vibratory flowmeter ( 5 ) if the meter stiffness value ( 216 ) falls within the predetermined stiffness range ( 219 ), and generate a verification failure indication for the vibratory flowmeter ( 5 ) if the meter stiffness value ( 216 ) does not fall within the predetermined stiffness range ( 219 ).

6. The vibratory flowmeter ( 5 ) of claim 1 , with the meter electronics ( 20 ) being further configured to vibrate the flowmeter assembly ( 10 ) in a secondary vibration mode using the first and second drivers ( 180 L, 180 R), determine first and second secondary mode currents ( 236 ) of the first and second drivers ( 180 L, 180 R) for the secondary vibration mode and determine first and second secondary mode response voltages ( 237 ) of the first and second pickoff sensors ( 170 L, 170 R) for the secondary vibration mode, and generate the meter stiffness value ( 216 ) using one or both of the first and second primary mode currents ( 230 ) and the first and second primary mode response voltages ( 231 ) or the first and second secondary mode currents ( 236 ) and the first and second secondary mode response voltages ( 237 ).

7. The vibratory flowmeter ( 5 ) of claim 1 , with the meter electronics ( 20 ) being further configured to generate a meter residual flexibility value ( 218 ) using the first and second primary mode currents ( 230 ) and the first and second primary mode response voltages ( 231 ).

8. The vibratory flowmeter ( 5 ) of claim 1 , with the meter electronics ( 20 ) being further configured to generate a meter residual flexibility value ( 218 ) using the first and second primary mode currents ( 230 ) and the first and second primary mode response voltages ( 231 ), compare the meter residual flexibility value ( 218 ) to a predetermined residual flexibility range ( 221 ), generate a verification indication for the vibratory flowmeter ( 5 ) if the meter residual flexibility value ( 218 ) falls within the predetermined residual flexibility range ( 221 ), and generate a verification failure indication for the vibratory flowmeter ( 5 ) if the meter residual flexibility value ( 218 ) does not fall within the predetermined residual flexibility range ( 221 ).

9. The vibratory flowmeter ( 5 ) of claim 1 , with the meter electronics ( 20 ) being further configured to vibrate the flowmeter assembly ( 10 ) in a secondary vibration mode using the first and second drivers ( 180 L, 180 R), determine first and second secondary mode currents ( 236 ) of the first and second drivers ( 180 L, 180 R) for the secondary vibration mode and determining first and second secondary mode response voltages ( 237 ) of the first and second pickoff sensors ( 170 L, 170 R) for the secondary vibration mode, and generate a meter residual flexibility value ( 218 ) using one or both of the first and second primary mode currents ( 230 ) and the first and second primary mode response voltages ( 231 ) or the first and second secondary mode currents ( 236 ) and the first and second secondary mode response voltages ( 237 ).