Many definitions in this standard are applicable to devices other than electron tubes ? especially semiconductor devices. These definitions have been made as general as possible, but it should always be remembered, in interpreting these definitions that they are primarily written for electron tubes. IEEE Std 161-1971, consists of IEEE Std 160-1957 as revised in part by the clarified definitions
of "noise factor" and "noise temperature" in IEEE Std 161-1962.