This part of ISO 3977 specifies the standard reference conditions and ISO standard ratings for gas turbines.
BS ISO 3977-2:2004 history
2023BS ISO 3977-2:2023 Gas turbines. Procurement. Standard reference conditions and ratings
2004BS ISO 3977-1:2004 Gas turbines - Procurement - General introduction and definitions
1992BS 3863:1992 Guide for gas turbines procurement
BS ISO 3977-2:2004 Gas turbines - Procurement - Standard reference conditions and ratings has been changed from BS 3863:1992 Guide for gas turbines procurement.