... program control,when synthesis of chromatography and vacuum distillation, to gradually control the vacuum degree(gradient control needs to another ... for example: Methylene chloride,benzene, Trichloro ethane,and ethanal etc .Vacuum controller can replace the inert gas so ... specifications 220VA 50Hz 1,“Set” set vacuum Numerical value2,“Start” started operation3,“start” and “Pause” is the same button4,“ ...