Alternate Method For Calculating The Meter Factor For Volume Flow - Emerson Micro Motion 1700 Configuration And Use Manual

Procedure
1.
2.
3.
Example: Calculating the meter factor for mass flow
The flowmeter is installed and validated for the first time. The mass flow measurement
from the transmitter is 250.27 lb. The mass flow measurement from the reference device
is 250 lb. The mass flow meter factor is calculated as follows:
The first meter factor for mass flow is 0.9989.
One year later, the flowmeter is validated again. The mass flow measurement from the
transmitter is 250.07 lb. The mass flow measurement from the reference device is
250.25 lb. The new mass flow meter factor is calculated as follows:
The new meter factor for mass flow is 0.9996.
9.4.1 Alternate method for calculating the meter factor for
volume flow
The alternate method for calculating the meter factor for volume flow is used to avoid the
difficulties that may be associated with the standard method.
This alternate method is based on the fact that volume is inversely proportional to density.
It provides partial correction of the volume flow measurement by adjusting for the portion
of the total offset that is caused by the density measurement offset. Use this method only
when a volume flow reference is not available, but a density reference is available.
Procedure
1.
2.
Configuration and Use Manual
Determine the meter factor as follows:
a. Use the flowmeter to take a sample measurement.
b. Measure the same sample using the reference device.
c. Calculate the meter factor using the following formula:
NewMeterFactor
=
Ensure that the calculated meter factor is between 0.8 and 1.2, inclusive. If the
meter factor is outside these limits, contact Micro Motion customer service.
Configure the meter factor in the transmitter.
MeterFactor
MassFlow
MeterFactor
MassFlow
Calculate the meter factor for density, using the standard method (see
Calculate the meter factor for volume flow from the meter factor for density:
ConfiguredMeterFactor
250
x
= 1
250.27
250.25
x
0.9989
=
250.07
Measurement support
ReferenceMeasurement
x
FlowmeterMeasurement
= 0.9989
= 0.9996
Section 9.4).
153