The Testo 425 Thermal Anemometer with telescopic probe enables simple, fast, and precise measurement of air velocity and volume flow in ventilation and air conditioning ducts. It covers 0–5905 fpm velocity and -4–158°F temperature, with automatic calculation of volume flow and time/point averages.

The telescopic probe extends up to 32 inches for flexible measurements in overhead or large-diameter ducts. Connection to the Testo Smart App turns your phone into a secondary display, supports configuration, data storage, and documentation. Measurements can be exported as PDF or CSV and shared via email.

Features

• -4 to 158°F temperature range
• 0 to 5905 fpm air velocity range
• Timed and point mean value calculation
• Fast in-app configuration and data memory
• Durable compact design with robust housing
• °F, °C, fpm, m/s, cfm, m³/h units