By measuring differential pressure across the pressure ports, and referring to the matching performance curve, airflow can be precisely determined.
Ten sizes are available, from 4 to 32 in., with capacities to 20,000 cfm. Iris dampers are made from galvanized steel. The dampers are fitted with a neoprene gasket for airtight mounting and come in stainless-steel and motorized versions.
Continental Fan Mfg. Inc. 203 Eggert Rd. Buffalo, NY 14215 (800) 779-4021 continentalfan.com