testo 435-4 – Multifunction indoor air quality meter | Testo Finland

Flow measurement in the ventilation duct using a thermal anemometer and vane anemometer

Testo offers compact anemometer probes and pitot tubes for measuring the flow and volumetric flow in the ventilation duct.

Selecting a suitable probe or measuring instrument depends on the flow velocity in the ventilation duct. This can be broken down into three sub-ranges:

• Low flow velocities: 0 to 5 m/s => thermal anemometers and thermal probes are suitable for this (order no. 0635 1535, 0635 1025)
• Medium flow velocities: 5 to 40 m/s => best results are achieved by the 16 mm vane anemometer und Flügelrad-Sonden (order no. 0635 9535)
• High flow velocities: 40 70 100 m/s => the pitot tube provides the best prerequisites (see following application)

The flow sensors for duct measurement are all equipped with telescopes making them easy to use in large air ducts. Air temperature and humidity can also be measured with the same probe as the flow velocity if required. According to the required application, choose between a thermal probe, vane probe or pitot tube for measuring the flow measurement in the duct.