Bronkhorst FlowTune - Manual (Page 10)

BRONKHORST
available. The unit type determines the unit list at Unit. The text field and slider at the right both represent the Full
scale capacity of the fluidset in the instrument expressed in the selected unit, i.e. the capacity at which the instrument
points 100% measure. The fluid structure formula is shown at Fluid.
To change the full scale capacity, edit the value in the text field or move the slider. The minimum and maximum
allowed full scale capacity is indicated at the slider. The unit in which the capacities are expressed can be changed at
Unit, after which the capacity in the previous unit is converted to the capacity in the new unit. For instrument
operation, this action has no effect other than changing the real output value and unit.
In addition to the capacity and the unit, the fluid and fluid conditions can be changed for fluidsets which are not
factory set. The fluid pull‐down is enabled in this case. Also enabled are the Actual conditions, i.e. the operating
Pressure inlet, Pressure outlet and Temperature. One or more of these conditions can be changed after which the full
scale capacity range can be recalculated. The pressure conditions must be entered in bar (a) with a maximum of 10
bar (a). The allowed temperature range is 0 to 70 °C. Changes which are not yet calculated are highlighted in yellow
and the Calculate range button is enabled.
Once a new fluid is selected from the list or the Calculate Range button is pressed, FlowTune calculates the fluid
properties, converts the calibration curve, calculates the new capacity range and a new controller gain (Kp). These
calculations are performed based on properties from the instrument and the FlowTune databases. Conversion is
based on fluid properties, sensor and restriction properties, valve properties and the original calibration curve. This
ensures the conversion and the new ranges to be calculated correctly. The result of these calculations is visualized in
the indicators in the right part of the window. One or two indicators (depending on the type of instrument) show a
capacity range, the upper one for the sensor and the lower one for the valve (available for controllers only). A valid
capacity range is indicated in blue, whereas an invalid capacity range is indicated in red. Both capacity ranges are
calculated based on the properties of the instrument, the selected fluid and the actual conditions. The full scale
capacity can be scaled in the area where the two ranges overlap. Dotted lines at the minimum and the maximum
allowed full scale capacity point out the resulting full scale capacity range as shown in the slider.
For some applications, it may be needed to adjust the controller speed. This can be done by moving the Speed slider
at the Controller settings section to faster or slower. The speed slider represents a multiplier for the controller gain.
The value 1 is marked by nominal, at which the controller gain calculated by FlowTune is used.
After the desired changes have been made, the changed or new fluid can be accepted and written to the instrument
by clicking OK. Note that the calibration curve of that fluidset is overwritten in case a fluid conversion has been
perfomed. On Cancel no changes are made to the instrument.
Changes have no effect on the instrument settings until confirmed by the OK button. On OK, the new
settings are written to the instrument and the window is closed. On Cancel no changes are made to the
instrument.
3.2.2 Remove a fluidset
Fluidsets added by FlowTune can also be removed from the instrument. The Remove button in the main window
removes the selected fluidset from the instrument. The active fluidset or factory set fluidsets cannot be removed.
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