Flow Damping
controls the amount of damping that will be applied to the measured mass flow rate. It affects
flow rate process variables that are based on the measured mass flow rate. This includes volume flow rate and
gas standard volume flow rate.
Flow Damping
also affects specialized flow rate variables such as temperature-corrected volume flow rate
(API referral) and net mass flow rate (concentration measurement). It is not applied to the flow rate received
via the frequency input.
Damping is used to smooth out small, rapid fluctuations in process measurement. The 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 of the process variable (the damped value) will reflect 63% of the
change in the actual measured value.
Procedure
Set
Flow Damping
to the value you want to use.
•
Default: 0.64 seconds
•
Range: 0 seconds to 60 seconds
Note
If a number greater than 60 is entered, it is automatically changed to 60.
Tip
•
A high damping value makes the process variable appear smoother because the reported value changes
slowly.
•
A low damping value makes the process variable appear more erratic because the reported value changes
more quickly.
•
The combination of a high damping value and rapid, large changes in flow rate can result in increased
measurement error.
•
Whenever the damping value is non-zero, the reported measurement will lag the actual measurement
because the reported value is being averaged over time.
•
In general, lower damping values are preferable because there is less chance of data loss, and less lag time
between the actual measurement and the reported value.
•
The transmitter automatically rounds off any entered damping value to the nearest valid value. Therefore,
the recommended damping value for gas applications should be 3.2 seconds. If you enter 2.56, the
transmitter will round it off to 3.2.
•
For filling applications, Micro Motion recommends using the default value of 0.04 seconds.
Configure process measurement
Configuration and Use Manual
April 2019
MMI-20048166
26
Micro Motion 4200 Transmitters
