Hello Pannala,
During the BDC, conversion occurs using the conversion routine assigned to the domain of the field.
Check the conversion routine associated to the domain of the field in which you are getting.
refer to the below document, it might give you some hint.
http://wiki.scn.sap.com/wiki/display/SI/Unit+of+Measure+related+settings+in+SAP
Regards,
Tp