An apparatus for a rapid determination of hydrogen in iron and steel was designed by applying the argon carrier gas hot-extraction method. The sample was heated at 950～1100℃ in the stream of pure argon at the flow rate of about 80ml/min, and hydrogen extracted was sent together with argon into a hot palladium osmosis tube. After allowing hydrogen to diffuse into the vacuum through the tube, the hydrogen was collected in a manometer through a mercury diffusion pump and an automatic Toepler pump, by which the mount of hydrogen was determined within 25 min. The present method was applied to the determination of hydrogen in iron and steel samples and satisfactory results could be obtained
