| 摘要 |
Exhaust pressure in an exhaust system 15 that evacuates a processing furnace 2 is determined as absolute pressure by using a differential manometer 23, which measures the exhaust pressure as differential pressure, and a barometer, which measures atmospheric pressure as absolute pressure. An opening of a pressure regulating valve 25 is adjusted based on the absolute exhaust pressure thus determined so that pressure in the processing furnace 2 is regulated. |
