Emerson MICRO MOTION 2700, Configuration And Use Manual, Page: 36 / 374

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 setting is 0.05% of the sensor's rated maximum flow rate or a
value below the highest expected flow rate. Do not set
Mass Flow Cutoff
to 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.
Interaction between Mass Flow Cutoff and AO Cutoff
Mass Flow Cutoff
defines the lowest mass flow value that the transmitter will report as
measured.
AO Cutoff
defines the lowest flow rate that will be reported via the mA output. If
mA Output Process Variable
is set to
Mass Flow Rate
, the mass flow rate reported via the 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).
AO Cutoff affects only mass flow values reported via the mA output.
Example: Cutoff interaction with AO Cutoff lower than Mass Flow Cutoff
Configuration:
• mA Output Process Variable : Mass Flow Rate
• Frequency Output Process Variable : Mass Flow Rate
• AO Cutoff : 10 g/sec
•
Mass Flow Cutoff
:
15
g/sec
Result: If the mass flow rate drops below 15 g/sec, mass flow will be reported as 0, and 0
will be used in all internal processing.
Example: Cutoff interaction with AO Cutoff higher than Mass Flow Cutoff
Configuration:
•
mA Output Process Variable
:
Mass Flow Rate
•
Frequency Output Process Variable
:
Mass Flow Rate
• AO Cutoff : 15 g/sec
• Mass Flow Cutoff : 10 g/sec
Result:
• If the mass flow rate drops below 15 g/sec but not below 10 g/sec:
- The mA output will report zero flow.
Configure process measurement
28 Micro Motion ® Model 2700 Transmitters with Analog Outputs