How many years to change the registration certificate for the use of oxygen tanks

Three years. According to the query Daoki Baba, the oxygen chamber use registration card is valid for three years, after the expiration date need to be replaced. Oxygen chamber is the use of hyperbaric oxygen treatment of a medical device, oxygen chamber can simulate the high-pressure oxygen environment, in the high-pressure oxygen chamber, the body contains more than four times the usual oxygen, can be used to treat ischemic and hypoxic diseases.