ISO 5389:2005 applies to performance tests on turbocompressors of all types. ISO 5389:2005 does not apply to fans and high-vacuum pumps, or to jet-type compressors with moving drive components Turbocompressors comprise machines in which inlet, compression and discharge are continuous flow processes. The gas is conveyed and compressed in impellers and decelerated with further increase in pressure in fixed vaned or vaneless stators. ISO 5389:2005 is intended to provide standard provisions for the preparation, procedure, evaluation and assessment of performance tests on compressors as specified above. The acceptance test of the performance is based on this performance test code. Acceptance tests are intended to demonstrate fulfilment of the order conditions and guarantees specified in the contract.