An isosurface object is a surface upon which a particular variable has a constant value, called the "level". To create a new Isosurface, select Insert > User Defined > Isosurface from the main menu.
Set Variable to one of the available variables for
                        defining the isosurface. Type in the variable value, set it using the
                        embedded slider, or click in the box, click Enter
                            Expression
                        
  (to the right of the box), and enter an expression. Set
                        appropriate units for the variable. The isosurface connects all locations
                        with the specified variable value.
The option of using hybrid or conservative values is available. Unless you are postprocessing CFD results using Ansys TurboGrid, this option can be ignored. For details, see Hybrid and Conservative Variable Values.
See Color Tab for details.
Note:  You may color the isosurface using any variable or choose a constant
                        color. You should not select the Local range option
                        when coloring an isosurface with the variable used to define it. In this
                        case the local range is zero by definition, so a plot would be colored
                        according to the effects of round-off error.
See Render Tab for details.