Abstract: This report describes test results from an assessment of the acoustically treated 9×15 Foot Low Speed Wind Tunnel at the NASA Glenn Research Center in Cleveland, Ohio in July of 2016. The tests were conducted in accordance with the recently adopted international standard ISO 26101-2012 on Qualification of Free Field Test Environments. This method involves moving a microphone relative to a source and comparing the sound pressure level versus distance measurements with theoretical inverse squar…