Technical Specifications

633
Menu - Configure
Simple - Compound Linkage Configuration
SIMPLE LEVER
The simple lever has the pivot point (the potentiometer in the SVI) mounted a fixed distance
(L1) from the valve stem pickup point. To compute the proper correction curve:
1. Enter the stroke length, the distance from the pivot to the valve stem pickup point and
the valve position at horizontal.
2. Click Simple to compute the correction and display the curve.
COMPOUND LEVER
The compound linkage has two lever segments attached at one end to the pivot (the
potentiometer in the SVI) and the other end to the valve stem pickup point. To compute the
proper correction curve:
1. Enter the stroke length, first lever segment length (L1), second lever segment length (L2),
the distance from the pivot to the valve stem pickup (L3), the valve position at horizontal.
2. Click Compound to compute the correction and display the curve.
Most Masoneilan linkages use a linkage with L3 equal to L1, i.e. the second lever arm is
vertical when the first lever arm is horizontal. The correction computation correctly
computes the correction curve when L3 is not equal to L1, however L3 must be greater than
0 which requires that the valve stem pickup not be lined up with the pivot and that the
pickup be on the same side of the pivot as the link between the first and second lever
segments.
Menu - Configure
When you right-click on the Configure tab, a context menu appears:
 Custom Linearization - Displays the Custom Linearization tab to allow correction for
linkage non-linearity. The Custom Linearization tab creates a custom
characterization that linearizes the valve movement with respect to the input signal.
 Detach Trend - Removes the trend display from the tabbed dialog and creates a
separate trend display.
 Help - Displays the help file at the Configure tab instructions