407119A Datasheet, PDF (11/12 Pages) Extech Instruments Corporation. – Heavy Duty Hot Wire CFM Thermo-Anemometer

Useful Equations and Conversions
Area equation for rectangular or square ducts
Width (W)
Height (H)
Area (A) = Width (W) x Height (H)
Area equation for circular ducts
Radius
Area (A) = x r²
Where = 3.14 and r² = radius x radius
Cubic equations
CFM (ft³/min) = Air Velocity (ft/min) x Area (ft²)
CMM (m³/min) = Air Velocity (m/sec) x Area (m²) x 60
NOTE: Measurements made in inches
must be converted to feet or meters before using the above formulae.
Unit of Measure Conversion Table
1 m/s
1 ft/min
1 knot
1 km/h
1 MPH
m/s
1
0.00508
0.5144
0.2778
0.4464
ft/min
196.87
1
101.27
54.69
87.89
knots
km/h
MPH
1.944
3.6
2.24
0.00987
0.01829
0.01138
1
1.8519
1.1523
0.54
1
0.6222
0.8679
11
1.6071
1
Model 407119A Version 5.0 October 2005