Configuration and Use Manual
MMI-20019053
Configure process measurement
October 2022
4 Configure process measurement
4.1 Configure mass flow measurement
The mass flow measurement parameters control how mass flow is measured and reported.
4.1.1 Configure Mass Flow Measurement Unit
Display
ProLink III
Field Communicator
OFF-LINE MAINT → OFF-LINE CONFG → UNITS → MASS
Device Tools → Configuration → Process Measurement → Flow
Configure → Manual Setup → Measurements → Flow → Mass Flow Unit
Mass Flow Measurement Unit specifies the unit of measure that will be used for the mass flow rate. The unit used for mass total and mass inventory is derived from this unit.
You can configure the mA and Frequency Outputs independently. For example, you can configure the mA
Output for mass flow and the Frequency Output for liquid volume or gas standard volume. If the same process variable is assigned to both the mA and Frequency Outputs, then any selected measurement unit,
(mass, volume or gas standard volume), is automatically applied to both outputs.
Procedure
Set Mass Flow Measurement Unit to the unit you want to use.
The default setting for Mass Flow Measurement Unit is g/sec (grams per second).
Tip
If the measurement unit you want to use is not available, you can define a special measurement unit.
Options for Mass Flow Measurement Unit
The transmitter provides a standard set of measurement units for Mass Flow Measurement Unit , plus one user-defined special measurement unit. Different communications tools may use different labels for the units.
Unit description
Grams per second
Grams per minute
Grams per hour
Kilograms per second
Kilograms per minute
Kilograms per hour
Kilograms per day
Metric tons per minute
Metric tons per hour
Display
G/S
G/MIN
G/H
KG/S
KG/MIN
KG/H
KG/D
T/MIN
T/H
ProLink III
Label g/sec g/min g/hr kg/sec kg/min kg/hr kg/day mTon/min mTon/hr
Field Communicator g/s g/min g/h kg/s kg/min kg/h kg/d
MetTon/min
MetTon/h
Configuration and Use Manual 19
Configure process measurement
October 2022
Configuration and Use Manual
MMI-20019053
Unit description
Metric tons per day
Pounds per second
Pounds per minute
Display
T/D
LB/S
LB/MIN
Pounds per hour
Pounds per day
LB/H
LB/D
Short tons (2000 pounds) per minute ST/MIN
Short tons (2000 pounds) per hour ST/H
Short tons (2000 pounds) per day
Long tons (2240 pounds) per hour
Long tons (2240 pounds) per day
Special unit
ST/D
LT/H
LT/D
SPECL
ProLink III
Label mTon/day lbs/sec lbs/min lbs/hr lbs/day sTon/min sTon/hr sTon/day lTon/hr lTon/day special
Field Communicator
MetTon/d lb/s lb/min lb/h lb/d
STon/min
STon/h
STon/d
LTon/h
LTon/d
Spcl
Define a special measurement unit for mass flow
Display
ProLink III
Field Communicator
Not available
Device Tools → Configuration → Process Measurement → Flow → Special Units
Configure → Manual Setup → Measurements → Special Units → Mass Special Units
A special measurement unit is a user-defined unit of measure that allows you to report process data, totalizer data, and inventory data in a unit that is not available in the transmitter. A special measurement unit is calculated from an existing measurement unit using a conversion factor.
Note
Although you cannot define a special measurement unit using the display, you can use the display to select an existing special measurement unit, and to view process data using the special measurement unit.
Procedure
1. Specify Base Mass Unit .
Base Mass Unit is the existing mass unit that the special unit will be based on.
2. Specify Base Time Unit .
Base Time Unit is the existing time unit that the special unit will be based on.
3. Calculate Mass Flow Conversion Factor as follows: a) x base units = y special units b) Mass Flow Conversion Factor = x ÷ y
The original mass flow rate value is divided by this value.
4. Enter Mass Flow Conversion Factor .
5. Set Mass Flow Label to the name you want to use for the mass flow unit.
20 Micro Motion 2700 Transmitters with Configurable Input/Outputs
Configuration and Use Manual
MMI-20019053
Configure process measurement
October 2022
6. Set Mass Total Label to the name you want to use for the mass total and mass inventory unit.
The special measurement unit is stored in the transmitter. You can configure the transmitter to use the special measurement unit at any time.
Example: Defining a special measurement unit for mass flow
You want to measure mass flow in ounces per second (oz/sec).
1. Set Base Mass Unit to Pounds (lb).
2. Set Base Time Unit to Seconds (sec).
3. Calculate Mass Flow Conversion Factor : a. 1 lb/sec = 16 oz/sec b.
Mass Flow Conversion Factor = 1 ÷ 16 = 0.0625
4. Set Mass Flow Conversion Factor to 0.0625
.
5. Set Mass Flow Label to oz/sec .
6. Set Mass Total Label to oz .
4.1.2 Configure Flow Damping
Display
ProLink III
Field Communicator
Not available
Device Tools → Configuration → Process Measurement → Flow
Configure → Manual Setup → Measurements → Flow → Flow Damping
Damping is used to smooth out small, rapid fluctuations in process measurement. Damping Value specifies the time period (in seconds) over which the transmitter will spread changes in the process variable. At the end of the interval, the internal value will reflect 63% of the change in the actual measured value.
Procedure
Set Flow Damping to the value you want to use.
The default value is 0.8 seconds. The range depends on the core processor type and the setting of Update
Rate , as shown in the following table.
Update Rate setting
Normal
Special
Damping range
0 to 51.2 seconds
0 to 40.96 seconds
The value you enter is automatically rounded off to the nearest valid value. For example, if the damping is currently set to 0.8 seconds, any value entered up to 1.2 seconds will be rounded down to 0.8 seconds, and any value entered from 1.21 to 1.59 seconds will be rounded up to 1.6 seconds.
Update Rate setting
Normal
Special
Valid damping values
0.0, 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, 12.8, 25.6, 51.2
0.0, 0.04, 0.08, 0.16, 0.32, 0.64, 1.28, 2.56, 5.12, 10.24,
20.48, 40.96
Configuration and Use Manual 21
Configure process measurement
October 2022
Configuration and Use Manual
MMI-20019053
Effect of flow damping on volume measurement
Flow damping affects volume measurement for liquid volume data. Flow damping also affects volume measurement for gas standard volume data. The transmitter calculates volume data from the damped mass flow data.
Interaction between Flow Damping and mA Output Damping
In some circumstances, both Flow Damping and mA Output Damping are applied to the reported mass flow value.
Flow Damping controls the rate of change in flow process variables. mA Output Damping controls the rate of change reported through mA Output. If mA Output Process Variable is set to Mass Flow Rate, and both
Flow Damping and mA Output Damping are set to non-zero values, flow damping is applied first, and the added damping calculation is applied to the result of the first calculation.
4.1.3 Configure Mass Flow Cutoff
Display
ProLink III
Field Communicator
Not available
Device Tools → Configuration → Process Measurement → Flow
Configure → Manual Setup → Measurements → Flow → Mass Flow Cutoff
Mass Flow Cutoff specifies the lowest mass flow rate that will be reported as measured. All mass flow rates below this cutoff will be reported as 0.
Procedure
Set Mass Flow Cutoff to the value you want to use.
The default value for Mass Flow Cutoff is 0.0 g/sec or a sensor-specific value set at the factory. The recommended value is 0.5% of the nominal flow rate of the attached sensor. See the sensor specifications. Do not leave Mass Flow Cutoff at 0.0 g/sec.
Effect of Mass Flow Cutoff on volume measurement
Mass Flow Cutoff does not affect volume measurement. Volume data is calculated from the actual mass data rather than the reported value.
Volume flow has a separate Volume Flow Cutoff that is not affected by the Mass Flow Cutoff value.
Interaction between Mass Flow Cutoff and mA Output Cutoff
Mass Flow Cutoff defines the lowest mass flow value that the transmitter will report as measured.
mA Output Cutoff defines the lowest flow rate that will be reported through mA Output. If mA Output
Process Variable is set to Mass Flow Rate, the mass flow rate reported through mA Output is controlled by the higher of the two cutoff values.
Mass Flow Cutoff affects all reported values and values used in other transmitter behavior (e.g., events defined on mass flow).
mA Output Cutoff affects only mass flow values reported through mA Output.
22 Micro Motion 2700 Transmitters with Configurable Input/Outputs
