Compressed Air Quality Testing Compressed air is widely used throughout industry, with over 90% of manufacturing industries globally using compressed air in one form or another. To be a safe, reliable and cost-effective utility, compressed air must be treated. Many facilities use international standards to specify the purity (quality) of compressed air they require for their applications and this will dictate the compressed air treatment equipment installed. Once the compressed air treatment equipment is installed and operating, users often require ‘proof’ the specified air purity (quality) is being achieve.