Level control tuning methods assume a linear relationship between liquid volume and level indication. While this is true for vertical cylindrical vessels, it is not the case for horizontal cylinders (especially those with dished ends) and spheres.

This module enables the user to determine the volume of liquid between the level indications of 0 and 100%. This parameter is key to the calculation of tuning for both tight and averaging level control. The module also provides a plot of liquid volume versus level indication. This can be used to assess whether there is likely to a problem with linearity. If so, a cubic approximation to the linearisation function is displayed. This would provide a measurement to the level controller that is in % of working volume rather than % of maximum level. Alternatively the user can explore relocating or re-ranging the level gauge.