Siemens SITRANS FC330, Руководство по эксплуатации, Страница: 132 / 280

Manual zero point adjustment
In case an automatic zero point adjustment cannot be performed, it is possible to do a manual
zero point adjustment by entering the zero point offset value.
1. Select "Manual" in "Zero point adjustment" (menu item 2.1.3).
2. Enter the desired value in "Offset" (menu item 2.1.3.7).
8.2.3 Low flow cut-off
In certain applications, as for instance dosing applications, 0% flow signals below a certain
flowrate are desired. In these applications, the flow signal can be forced to zero, when the flow
is lower than a predefined flow value (Low Flow Cut-Off).
The device provides two parameters for setting the low flow cut-off:
● Low Mass Flow Cut-Off
● Low Volume Flow Cut-Off
The low flow cut-off parameters influence all outputs of the device, for example Local User
Interface, Channel 1 to 4, and bus communication outputs.
Depending on the process values selection of the output either Low Mass Flow Cut-Off or Low
Volume Flow Cut-Off will influence the output.
8.2.4 Empty tube monitoring
The empty tube monitoring function uses the process density for detecting an empty tube. Use
of this function is recommended for all standard applications.
Note
Gas applications
Deactivate the empty tube monitoring function.
Empty tube monitoring parameters
Two parameters for setting the empty tube monitoring function are available:
● Empty Tube Detection (Modbus address 2129)
● Empty Tube Limit (Modbus address 2127)
The empty tube monitoring is activated via the Empty Tube Detection parameter. When the
empty tube monitoring function is on, the mass flow / volume flow value is forced to zero if the
tube is empty.
Parameter assignment
8.2 Functions
SITRANS FC330
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Operating Instructions, 01/2019, A5E44030648-AB