Registering Custom Units
1.Click File > Info > Project Database Properties.
2.In the Project Database Properties dialog box that appears, click on the Unit Manager tab.
3.Click on the button Edit table of custom units on the tab to open the Table of Custom Units dialog box.
4.From the Table list box, choose the table that you want to edit.
5.Click on Insert item or press the INSERT key.
6.In the Unit column of the list, enter the symbol of the new unit using the correct case-sensitive. You cannot use symbols that are already assigned to other units.
7.Now click on the field to the right of the symbol and enter the representation of the unit in SI units. Please note the following rules for entering a unit:
•You can use any SI units you want during input and not just the seven base units, such as "N" or "W".
•Enter "1" for a dimensionless unit.
•Unit symbols are case-sensitive, which means, for instance, that "S" is the symbol for the unit "Siemens" and "s" is the unit for seconds.
•Use a space for multiplication, e.g. "N m" instead of "Nm".
•Use the '^' character for exponents, e.g. "m^2".
•Use the '/' character for division, e.g. "m/s^2".
•Use parentheses correctly, e.g. "kg/(kW h)".
•You can specify an SI prefix or a factor, e.g. "mm" or "0.001 m".
•You can specify an offset, e.g. "K−273.15".
8.If you want to allow the use of an SI prefix for your new unit, click in the Allow SI Prefix column and select Yes.
9.Click Close to accept your changes.
Note: You cannot edit the unit tables in the shared template databases directly. For instance, to add a unit to a shared template database, you first have to register it in the current project database or the personal template database as described here and then copy it to the shared template database, as described in Organizing Units.