This Code provides standard procedures for conducting and reporting tests on fans, including those of the centrifugal, axial and mixed flow types. This Code provides the rules for testing fans to determine performance under actual operating conditions. It also provides additional rules for converting measured performance to that which would prevail under specified operating conditions. Some of the quantities that can be determined include fan mass flow rate, fan specific energy and fan input power. The scope of this Code is limited to the testing of fans after they have been installed in the systems for which they were intended. However, the same directions can be followed in a laboratory test. (The laboratory test performance may not be duplicated by a test after installation because of system effects.) The term fan implies that the machine is used primarily for moving air or gas rather than compression. The distinction between fans, blowers, exhausters, and compressors in common practice is rather vague; accordingly, machines that bear any of these names may be tested under the provisions of this Code.