US 10,890,479 B2
Vibratory flowmeter and methods and diagnostics for meter verification
Timothy J Cunningham, Boulder, CO (US); David J Kapolnek, Broomfield, CO (US); Matthew J Rensing, Cincinnati, OH (US); and Christopher George Larsen, Cincinnati, OH (US)
Assigned to Micro Motion, Inc., Boulder, CO (US)
Appl. No. 15/108,627
Filed by Micro Motion, Inc., Boulder, CO (US)
PCT Filed Dec. 19, 2014, PCT No. PCT/US2014/071558
§ 371(c)(1), (2) Date Jun. 28, 2016,
PCT Pub. No. WO2015/112296, PCT Pub. Date Jul. 30, 2015.
Claims priority of provisional application 61/931,421, filed on Jan. 24, 2014.
Prior Publication US 2016/0320227 A1, Nov. 3, 2016
Int. Cl. G01F 25/00 (2006.01); G01F 1/84 (2006.01)
CPC G01F 25/0007 (2013.01) [G01F 1/84 (2013.01); G01F 1/8436 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A vibratory flowmeter (5) having meter verification, the vibratory flowmeter (5) comprising:
a flowmeter assembly (10) including one or more flowtubes (130, 130′) and first and second pickoff sensors (170L, 170R);
a driver (180) configured to vibrate the one or more flowtubes (130, 130′); and
meter electronics (20) coupled to the first and second pickoff sensors (170L, 170R) and coupled to the driver (180), with the meter electronics (20) being configured to: vibrate the flowmeter assembly (10) in a single mode using the driver (180), determine a single mode current (230) of the driver (180) and determine first and second response voltages (231) generated by the first and second pickoff sensors (170L, 170R), respectively, compute frequency response functions for the determined first and second response voltages (231) from the determined single mode current (230), fit the generated frequency response functions to a pole-residue model to compute a meter stiffness value (216), compute a difference of meter stiffness values at the first and second pickoff sensors (170L and 170R), and verify proper operation of the vibratory flowmeter (5) using the computed difference of the meter stiffness values to detect erosion, corrosion, or coating of the flowtubes (130, 130′);
wherein the meter stiffness value (216) includes a correction for density.