Originated in part as part of AS 1924.1—1976 and AS 1924.2—1981.Previous edition AS 4685.4—2004.Second edition AS 4685.4:2014. Originated in part as part of AS 1924.1-1976 and AS 1924.2-1981. Previous edition AS 4685.4-2004. Second edition AS 4685.4:2014.