This company's iris damper means that now a single device will permit airflow to be adjusted and measured at one location. This reduces field time and improves accuracy in air balancing. The iris damper uses interlocking steel plates and a calibrated control lever to form an adjustable aperture. It can measure differential pressure across the pressure ports and refer to the matched performance curve to precisely determine airflow. Ten sizes are available and capacities range from 15-25,000 cfm.

Continental Fan Manufacturing Inc., 203 Eggert Road, Buffalo, NY 14215; 800/779-4021;