Scaling factor = iRatioTechUnitsNum [IEC/rev] / dwRatioTechUnitsDenom [Increments/rev
dwRatioTechUnitsDenom : DWORD → 0·······4294967295
iRatioTechUnitsNum : INT → -32768·······32767
dwRatioTechUnitsDenom : DWORD → 0·······4294967295
iRatioTechUnitsNum : INT → -32768·······32767