An air flow differential pressure switch (AFDPS) is a device that monitors the difference of air pressure between two points in a system. It’s typically used to detect changes in air velocity due to blockages, leaks or obstructions in an airway system, allowing for corrective measures to be taken. By creating an alarm when a predetermined air pressure level is exceeded, an AFDPS can help keep an airway system functioning at peak efficiency and potentially save costs associated with costly repairs.