Description:

Model DFS221 is an airflow proving switch designed for duct heater, oven, and other HVAC or Energy Management applications where an open-mounted, nonadjustable switch is desirable. It is especially suitable for surface-mounting in areas where internal access is limited. It can be used to sense positive, negative, or differential air pressure. The DFS221 is equipped with a convenient barbed sample line connector that accepts flexible tubing.

Air Switch Glossary Here.