Section R. 408.10946 - InspectionRule 946.
(1) A carbon dioxide extinguishing system shall be inspected by a trained and authorized employee or outside service:(a) Not less than annually to insure operability.(b) Not less than semiannually to insure that all high pressure cylinders are at the designed weight. A cylinder showing a net loss in weight of more than 10% shall be refilled or replaced.(c) Not less than annually to check the accuracy of low pressure system liquid level gauges.(d) If a container shows a loss of more than 10%, it shall be refilled, unless the minimum gas requirements are still provided.(2) A tag shall be affixed indicating the date of inspection.Mich. Admin. Code R. 408.10946