METHOD FOR CONTROLLING LOW OXYGEN AND HIGH SULFUR PARTIAL PRESSURE

摘要

PURPOSE:To enable the exact control of the mixing ratio of an atmospheric gas by a chemical method to a desired value by circulating the gases to be controlled among an oxygen partial pressure control part and a sulfur partial pressure control part and a measuring part. CONSTITUTION:The oxygen partial pressure control part 1 consists of an oxygen ion conductive zirconia oxygen pump 4 and an oxygen sensor 6. The output of the oxygen sensor 6 is sent to a driving power supply 10 which drives the oxygen pump 4 so that the feedback control of the quantity of the oxygen in the system is executed. The quantity of the oxygen is the atmospheric gas is controlled by executing the oxidation/reduction of the gaseous hydrogen introduced into said part. The sulfur partial pressure control part 3 is constituted by packing cobalt sulfide CoS powder 28 into an alumina tube 13. Gaseous hydrogen sulfide is generated by the chemical equil. reaction of the gaseous hydrogen introduced into said part and the cobalt sulfide, by which the quantity of the sulfur in the atmosphere gas is controlled. The measuring part 2 consists of an oxygen sensor 14 provided in an alumina tube 12. The output of the sensor can be checked by a recorder 18. High-purity gaseous hydrogen 30 is used as the circulating gas. After the inside of the system is evacuate, the gas is introduced into the system and the prescribed partial pressures of the oxygen and sulfur are controlled.