dim objDoc as your SE document, you can reference the units of measure by
There are several types (Length, Angle, Mass etc) that you can reference by using it's item number (x):
item(1) = Linear
item(2) = angular
This will return an integer, to decode look up the UnitOfMeasure Enumerations in your SDK help file. So for linear units look at UnitOfMeasureLengthReadoutConstants Enumeration; 17 is milimeters, 15 is meters ect. Using some handy code and arrays you can match the integer with a string so you get text instead of numbers.