Hello.
I recently replaced a flowmeter and transmitter in a facility for measuring the mass flow rate and the density of liquid oxygen.
I plotted a figure which shows the relationship between the measured mass flow rate and the calculated one from the flow coefficient of an object at the end of the facility. (below graph)
As you can see, at first, the flow meter showed coincident data(red circles, o) with the old one(black circles, o).
But, recently the flowmeter seems to show somewhat biased values(purple circles, o) from the previous data.
I wonder if there is any possible reason of getting biased mass flow rates from the coriolis meter and then why.
I also want to know how to check the integrity of the sensor.
Thank you.
Here are the flow meter and transmitter specs.
Model: CMF100HB33NRAIEZZX_36020CMF100H MICRO MOTION ELITE CORIOLIS METER, 1 INCH (DN25), NICKEL ALLOY C22B33 Process Connections: 1-inch CL900/1500 ASME B16.5 F304/F304L Lap joint flange N06022 stubN Case Options: Standard pressure containmentR Electronics Interface: 9-wire polyurethane-painted aluminum J-boxA Conduit Connections: No glandI Approvals: IECEx Zone 1E Language: English installation manualZ Calibration Options: 0.10% mass flow and 0.0005 g/cc density calibrationZ Measurement Application Software: No measurement application softwareX Factory Options: ETO Product36020 ETO Number: CRYO TEMP CYCLING MODIFICATIONS WITH J-BOX TO -240C(AMBIENT ANDFLUID) ON A CMF100H
Model 2700R12BBIEZZZPK2700 MICRO MOTION 2700 FIELD AND INTEGRAL-MOUNT MULTIVARIABLE FLOW AND DENSITYTRANSMITTERR Mounting: 4-wire Remote Mount Transmitter (Polyurethane-Painted Aluminum Housing) includes10ft. [3m] 4 wire Shielded PVC Cable1 Power: 18 to 100 VDC and 85 to 265 VAC; Self Switching2 Display: Backlit Dual Line Display for CSA, UL, and IIB + H2 ATEX IECEx and NEPSI RatingsB Output: One mA; Two Configurable IO Channels - Default Configuration of 2 mA, 1 FOB Conduit Connections: 1/2-inch NPT - No glandI Approvals: IECEx- Equipment Category 2 ( Zone 1 - Flameproof Terminal Compartment )E Language: English Installation Manual and English Configuration ManualZ Software Options 1: Flow and Density Variables (Standard)Z Software Options 2: No Software Options 2Z Factory Options: Standard ProductPK Add on Option: 2-inch Pipe Mount U-Bolt Kit for Electronics
This is unexpected behavior in a application like yours. Typically, the only thing that could cause a change in a Coriolis meter mass flow bias error as suggested by this data would be some physical damage to the flow tubes inside the meter. Is it possible the meter may have experienced any extreme internal pressure that would be higher than the rated pressure? We have diagnostics called Smart Meter Verification (SMV) that can detect damage to the tubes, but I am not sure if your meter has this feature.
Please contact me by email at marc.buttler@emerson.com so that we can engage our engineers directly to help diagnose the problem for you.