You can add, edit and delete unit systems.
Add unit system
Click on the corresponding icon in the toolbar or make a right mouse click on a unit system column header and choose Add unit system.
A dialog opens, where you can enter a name and a description. Enter at least a unique name. It is not allowed to have multiple unit systems with the same name in the unit table. If you enter a description, it will be shown as tooltip when hovering the column header of a unit system in the table with the mouse.
Edit unit system
Make a right mouse click on the unit system column header and choose Edit unit system. A dialog opens, where you can edit the name and the description.
Delete unit system
Make a right mouse click on the column header of the unit system you want to delete and choose Delete unit system. Alternatively, you can click on the corresponding icon in the toolbar and select the unit system(s) to be deleted in the dialog.
Import/export unit systems
Use the corresponding icons in the toolbar for these functions.
You can import one or more unit systems from a file (*.ut).
In the import dialog you can select the unit system(s) to be imported. The primary unit system is always selected because it is the reference for the conversion. Existing units will be overwritten with new values during import. New units will be added.
You also can export one or more unit systems and save them in a file (*.ut).
In the export dialog you can select the unit system(s) to be exported. The primary unit system is always selected.

