• Measures air velocity, volume flow, and temperature
• Measures in-duct air flow and automatically calculates volume flow (enter duct dimensions simply)
• Small dia. (<0.5") and 15" telescopic shaft length is ideal for in-duct flow averaging and timed traverse
• Perform air duct leakage tests
• Measurement data is transmitted to the convenient and powerful testo Smart Probes App in your smart device
• Tough, accurate, and easy-to-use
• For all HVAC/R technicians and contractors

The testo 405i Smart Probe hot-wire anemometer is a wireless instrument for measuring air flow velocity, temperature, and volume flow. It is equipped with a telescopic shaft which extends to 15" for easy in-duct testing. You can reliably determine timed and multipoint flow traverses. Users can read the measurements using the testo Smart Probes App installed on their smart device. The app lets users configure duct dimensions to calculate volume flow measurements. Use the testo 405i along with the testo 605i thermo-hygrometer to determine cooling and heating performance. The testo 405i works on smart devices with either Android or Apple operating systems. The testo Smart Probes App is a powerful and easy-to-use tool. It allows you to remotely read measurements from up to six (6) Smart Probes and easily document/report the results. Automatic calculations make it a snap! All measurement data is displayed as instrument readings, tables, or graphs. The measurements can be quickly saved as PDF or Excel files. The App creates custom reports which can be saved and/or shared by email. All your data can be stored and retrieved saving you hours of time consuming paperwork! Testo Smart Probes: Compact Bluetooth Instruments The compact and wireless Smart Probes can be operated by a smartphone or tablet via the testo Smart Probes app, which also provides complete reports at the push of a button. These durable multi-function probes are perfect for all aspects of the HVAC field. The Smart Probes offer you the following • Comprehensive selection of measuring instruments: smartphone anemometer, iPhone (and Android) hygrometer, smartphone thermometer and lots more • Practical kits for the most important applications in heating, air conditioning, ventilation and refrigeration • Operation and documentation entirely via the testo Smart Probes App