This is the visual definition icon responsible for specifying how thermo curves are a Thermodynamic diagram background is displayed. It controls features such as line colour, line thickness and how missing data will be plotted.
The macro language equivalent is mthermo().
The Thermo Plotting Editor
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related to isotherms, isobars, mixing ratio lines, dry and moist adiabats.
Info
From Macro/Python the icon can be called as mthermogrid().
