P233F-P3-AAC | Differential Pressure Switch, 0.3 Mbar Fixed, No Differential, SPDT Contacts, No accessories included | Johnson Controls

This switch senses a change in the (differential) pressure as the airflow changes. The (differential) pressure is applied to the two sides of a diaphragm in the control. The spring-loaded diaphragm moves and actuates the switch. The series P233A/F can also be used to detect small positive gauge pressure or to detect a vacuum.