دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: diving in which a diver uses a normal atmospheric mixture of oxygen and nitrogen as a breathing medium. It is limited to depths less than 190 feet (58 metres) because of the dangers of nitrogen narcosis;however, dives with bottom times of 30 minutes or less may be conducted to a maximum of 220 feet (67 metres).