Upper and lower tolerances are set differently in PM and the old Sounding Grid Utility (SGU).
In SGU lower and upper tolerance should be set as positive.
In PM, upper tolerance is positive, lower tolerance is negative. This is not clear.
To understand the terminology in the volume results, the user needs to read the help
To make it clearer that the tolerances are related to the reference selected
Please only allow positive values to be entered like in the SGU and a small picture/drawing to make clear in the Calculation display.
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