KROHNE VFM 3100 EN - Manual (Page 60)

60
9.3. Transmitter Options
Flow Units [Pick-List]
This selection defines the units for the measured flow rate. Selecting
Special Units allows the user to define units not listed. The procedure
for doing this is described in chapter 5.
Default: USgpm
Total Units [Pick-List]
This selection defines the units for the measured total rate. Selecting
Special Units allows you to define units not listed. The procedure for
doing this is described in chapter 5.
Default: USgal
Noise Rejection [On,Off]
This selection allows the user to turn off the adaptive noise rejection
feature. When On, this feature improves VFM 3100 performance by
rejecting process noise. Off would normally be selected only for
troubleshooting the process.
Default: On
Signal Conditioning [On,Off]
This selection provides the user a means of turning off the low flow
signal conditioning feature. When On, this feature improves VFM
3100 performance by reducing the adverse effects of process noise
on the vortex signal. Off would normally be selected only for troubles-
hooting the process.
Low Flow Correction [On,Off]
This selection provides a means for turning on the low flow K-factor
correction. When On, this feature corrects for the nonlinearity of the
K-Factor that occurs at Reynolds Numbers below 20,000. The de-
fault for this parameter is Off to alert the user to the fact that actual
values of the Process Density and Viscosity must be entered into the
database to achieve improved accuracy.
Default: Off
Low Flow Cut-In [Pick-List]
The low flow cut-in parameter allows the user to set the level above
which the VFM 3100 begins to measure flow, i.e., the lower range li-
mit of the VFM 3100. This process can be carried out automatically if
the flow is turned off. Otherwise, manual selection from the following
pick-list of eight levels can be made:
AUTO, (L0), (L1), (L2), (L3), (L4), (L5), (L6), (L7)
For convenience, these levels are displayed as estimated flow rates
in the selected flow units. The value of these flow rates depend on
the specific application parameters.
Default: (L3)
9.4. Process Fluid Parameters
Fluid Type [Pick-List: Liquid, Gas, Steam]
Three options are available: Liquid, Gas, or Steam. Knowledge of the
process fluid type is necessary for the automatic selection of default
process fluid properties.
NOTE: If a standard volume output is desired, the user is required to
enter base density.
Default: Liquid
Process Temperature [numeric entry for value;
Pick-List for units: °F,°C]
This is the actual temperature at process conditions. It is needed to
make the thermal expansion correction to the K-Factor.
Default: 70 °F or 20 °C (depending on units of Reference K-Factor)
Process Density [numeric entry for value;
Pick-List for units: LB/FT3,KG/M3]
This is the actual density at process conditions. It is needed by the
VFM 3100 to compute internally the lower and upper flow range li-
mits. It is also needed to compute mass flow, if selected.
NOTE: Enter density, not specific gravity.
Default depends on selected fluid type and units of
Reference K-Factor:
• Liquid - 62.301 LB/FT3; 998.2 KG/M3
• Gas - 0.5858 LB/FT3; 9.546 KG/M3
• Steam - 0.2992 LB/FT3; 4.618 KG/M3
Base Density [numeric entry]
This information is only applicable if output in standard volume is de-
sired. Units are the same as those selected for the flowing density.
Default depends on selected fluid type and units of Reference
K-Factor:
• Liquid - 62.374 LB/FT3; 999.2 KG/M3
• Gas - 0.07634 LB/FT3; 1.293 KG/M3
•Steam - 0.03730 LB/FT3; 0.5977 KG/M3
Process Viscosity [numeric entry of value; Pick-List for units:
Absolute (CPOISE), Kinematic (CSTOKE)]
This is the actual viscosity at process conditions. It is required only if
the Low Flow Correction is On.
Default depends on selected fluid type and units of
Reference K-Factor:
• Liquid - 0.9753 CPOISE or 1.002 CPOISE
• Gas - 0.0186 CPOISE or 0.0185 CPOISE
• Steam - 0.0150 CPOISE or 0.0149 CPOISE
9.5. Application Parameters
Mating Pipe [Pipe Schedule Pick-List]
This menu selection allows the Reference K-factor to be corrected
internally for piping bore mismatch upstream of the VFM 3100. The
pick-list is as follows:
SCHED 10, SCHED 40, SCHED 80
PN 16, PN40, PN 64, PN 100
SANITARY
Default: SCHED 40 (corresponds to zero bias)