The flow velocity and flow in ventilation duct to determine, the testo 440 Set an effective measuring device directly to the work to begin!The testo 440 Set contains a compact hand-held meter and calibration protocol, a vane probe (Ø 100 mm) and a hot-wire probe. The probes are both Bluetooth-enabled and have a temperature sensor. The testo 440 hand-held measuring device is supplied with batteries and is ready for use immediately! To Set a suitable combination case included.The meter has a large, illuminated color display and has a structured measurement menu by pressing and specific temporal averaging, average volume flow, current measured value, as well as min/max values are displayed. You can also dimension and geometry of the channel cross-section must be entered to calculate an exact calculation of the volume flow. Other measurement menus as long-term measurement and volume flow measurement with funnel are also possible.The testo 440 meter collects and evaluates your measurement d