IEC 60041 - 1991, "FIELD ACCEPTANCE TESTS TO DETERMINE THE HYDRAULIC PERFORMANCE OF HYDRAULIC TURBINES, STORAGE PUMPS AND PUMP-TURBINES". CLAUSE 14 "THERMODYNAMIC METHOD FOR MEASURING EFFICIENCY" COMMENTS

Since the last revision of the test code IEC 60041 1991 there has been a large development in instrumentation and computers, and a lot of test experience has been gained. Some of the recommendations in the code were important because of insufficient accuracy and repeatability of the earlier instrumentation, as the code states in 14.1.3 “Instrumentation” that “the apparatus presently available varies widely and may possibly become obsolete in the future”. The introduction of new instruments and equipment may also introduce new problems not addressed in the present code.