Siemens SITRANS F Operating Instructions Manual page 14

Manual Addendum
To access the Digital Damping Control using the Test Facilities Graph Screen, proceed as follows:
1. To use the Test Facilities Graph Screen you must have a working site.
2. To activate the Test Facilities Graph Screen:
In the main menu, scroll to the [Diagnostic Data] menu and select [Test Facilities].
Scroll down to [Graph], press the <Right Arrow> and highlight [Yes]. Press <ENT> to select.
The Test Facilities Graphic Screen will appear on the meter display as shown below.
Setting the Digital Damping Factor to a value HIGHER than the default value of 4 may be necessary
in cases where the signal to noise ratio (SN) is found to be unacceptably low (<15:1), but only if the
noise is determined to be asynchronous (i.e., not associated with the transmit or flowmeter timing
circuitry) as shown in the signal example above, where the baseline noise has a higher frequency
than the true gas signal.
The following application conditions may require a higher Digital Damping Factor:
Close proximity to pressure control valves which may generate in-band acoustic noise
Very low acoustic signal levels (ALC < 40%)
High electronic noise from variable frequency drives or other external equipment.
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