Reading CFM and Duct Velocity with a Testo 510i, the Smart Probe app and a Pitot Tube
In this video we cover the basics of using the Testo 510i with a pitot tube to do a duct traverse and easily calculate Velocity in FPM and volume in CFM on a small 8″ duct. Using this method is handy because you can use the reliable, accurate and inexpensive 510i to perform the measurement without any other equipment other than tubes and a pitot tube.
As stated in the video, a pitot tube is best (most accurately) used in the following conditions –
- Medium to High Air Velocities
- With 4 -8 feet of hose
- In low turbulence air at least 8.5 diameters downstream of any turns, fittings or diffusers (I was less than this in the video resulting in lower accuracy)
- In a duct at least 30 times larger than the pitot tube diameter (It was less than this in the video resulting in lower accuracy)
For more information see the following links –
TruTech Tools Traverse Quick Chart
TruTech Measuring with a pitot tube
Video on the performance of a rectangular time average traverse
