English to Russian Tech/Engineering Metallurgy / Casting VD/VOD plant (��������� �����������������)

During this decarburization phase, an oxygen quantity, according to the existing analysis data, has to be blown. Especially for this final phase, the end of the decarburization treatment is exactly indicated ***by control of the exhaust gas analysis***.

VCD-Treatment
By further lowering of vacuum, the final decarburization is continued only by CO development. After termination of this so called "vacuum decarburization", one obtains an exact indication ***by the exhaust gas control***. Now the desired carbon content has been reliably adjusted.

Как вы это понимаете? Какой-то контроль (устройство контроля?) отработанных газов, от которого идут показания о стадии операции???