unit of measure

Dear Friends,

this is chandrashekar, i 'm working on ecc6.0 here i have unit of measure is T is calld ton so if i maintained in BUOM is in kgs and Oorder unit is TON in material master it is not asking for conversion factor if i'm procuring in po it showing TON only but it taking as 1kg = 1 ton like this it is updating in material stock how can i chainge this please tell me.

regards

chandu