The AIChE has a committee that addresses regularly AIChE’s equipment testing procedures. That committee includes a subcommittee that addresses the testing of trayed and packed columns. After three years of work, that subcommittee is ready to release a 150-page manual entitled, “Trayed and Packed Columns – A Guide to Performance Evaluation.” This will be the third edition of this manual. This presentation describes the third edition, especially changes with respect to earlier editions.