This application measure air flow in ventilation equipment. The primary use is balancing a ventilation system, that calculates the air flow with the following equation (Swegon and other brands). q = k · √ p (l/s)q = measured air flow (l/s)p = actual balancing pressure (Pa)k = k-factorIn order to measure a USB differential pressure sensor in needed. The price for the sensor is 150 EUR + VAT + shipping + customs duty, dispatched from Sweden. To order a sensor send a email to: firstname.lastname@example.orgA possible improvement to this app is to add a balancing protocol to reduce the paper work and speed up the work.