The most widely used performance standard for cleanrooms is ISO 14644 which imposes exacting requirements on the cleanroom user. Product quality and audit requirements work together to ensure that the end result is as was called for in the design. CON-TEST personnel are able to put their expertise to work to not only certify the Class of room, be it Class 10, 100 or 100,000, but to also maximize the range of capabilities for the room. From initial installation to annual recertification our technicians have kept the users interest paramount. NEBB cleanroom performance testing procedures are an integral part of the process. CON-TEST personnel helped write the procedural standards manual and regularly instruct at their courses on cleanroom performance. Particle counts, velocity profiles, airflow visualization and many other performance features of a cleanroom can be verified for the user. Where necessary we can lend our considerable experience to guide the user.