The climate measuring instruments testo 440 combine the benefits of a compact handheld device with intuitive measurement menus and a comprehensive selection of air velocity & IAQ probes. Both the digital Testo Smart Probes and numerous Testo temperature probes can be connected. Clearly structured menus for measuring volume flow in ducts/at outlets, degree of turbulence, cooling/heating load, mould indication and logging mode are stored on the instrument.