Damping; Meter Factors - Emerson Micro Motion 3711 Configuration And Use Manual

Configuring the Core Interface
Flow calibration values
Two separate values are used to describe flow calibration: a 6-character FCF value and a 4-character
FT value. Both values contain decimal points. On the sensor tags, these two values are concatenated
to form a 10-character string called Flow Cal or Flow Cal Factor (see Figure 5-5).
• For the FCF value, enter the first six characters of the string. In the sample tags in Figure 5-5,
this value is shown as
• For the FT value, enter the last four characters of the string. In the sample tags in Figure 5-5,
this value is shown as
5.5.2

Damping

You can configure damping for both mass flow measurement, density measurement, and temperature
measurement. Damping helps the transmitter smooth out small, rapid measurement fluctuations:
• A high damping value makes the output appear to be smoother because the output must change
slowly.
• A low damping value makes the output appear to be more erratic because the output changes
more quickly.
When you specify a new damping value, it is automatically rounded down to the nearest valid
damping value.
Valid damping values are listed in Table 5-4.
Table 5-4 Valid damping values
Process variable
Mass flow
Density
Temperature
Note: For typical gas applications, Micro Motion recommends a flow damping value of 3.2 (the
default).
5.5.3

Meter factors

Meter factors allow you to adjust the Model 3711's reported mass flow rate or density value to match
an external measurement standard. Meter factors are used for proving the meter against a Weights &
Measures standard. You may need to calculate and configure the meter factors periodically.
Use the following formula to calculate a meter factor:
NewMeterFactor
44
.
19.000
.
5.13
Valid damping values
0, .2, .4, .8, ... 51.2
0, .2, .4, .8, ... 51.2
0, .6, 1.2, 2.4, 4.8, ... 76.8
= ConfiguredMeterFactor
ExternalStandard
×
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ActualTransmitterMeasurement
Micro Motion
®
Model 3711 Gas Flow Computers