A venturi tube is a measurement device that uses the pressure differential between two sections that differ in diameter. Using Bernoulli’s principle, the velocity and flow rate can be approximated from the pressure differential measured across the two areas within the venturi tube. The venturi tube is a popular method of calculated volumetric flow rates for gases, water and oils, and other internally flowing fluids. The venturi tube given here is designed specifically for use with 80mm DC fans. The venturi tube has been used to verify fluid dynamics theory while also characterizing the relationship between duty cycle and flow rate of the fan. The fan included in this kit has been characterized to output approximately 75 cubic feet per minute (CFM). The kit also includes the XGMP3v3 differential pressure sensor (similar to the MPXV7002DP), which makes the kit a complete bundle for measuring real-world flows through a venturi tube.

See the Venturi Tube in action on Youtube.

Included in the Venturi Tube Flow Meter Kit:

• 1x 3D Printed Venturi Tube (236mm x 85mm x 85mm)

• 1x XGMP3v3 Differential Pressure Sensor (with JST-XH Connector)

• 1x 80mm x 38mm 12V DC Fan (+4x Screw Set)

• 2x Silicone Tubing (OD: 5mm, ID: 2.5mm, Length: 35cm Each)

• 20pcs Jumper Wires

Features of the Venturi Tube Flow Meter:

• Dimensions: 236mm x 85mm x 85mm

• Inlet Diameter: 76mm, Throat Diameter: 57mm

• Roughness ~ 32μm

• Most 80mm DC Fans Can be Affixed to Tube

• Two Pressure Taps for 5mm Tubing (Inlet, Throat)

Features of the XGMP3v3 Differential Pressure Sensor:

• -2.5 kPa to +2.5 kPa Measurement Range

• 3.3V Supply Voltage

• 24mA Max Power Consumption (10mW)

• Analog Output Range: 0.2V - 2.7V

• Measurement Accuracy: ±2.5% Full-Scale [kPa]

• Temperature Compensated from 0°C - 60°C

• Absolute Maximums: ±2x Pressure Max, -10°C to 85°C Operating Temperature

• For Use with Non-Corrosive Gas (Air, Inert [Helium, Neon, Argon, etc.])

• JST-XH Connector Makes Connection to Raspberry Pi or Arduino Simple

• XGMP3v3 Datasheet

Features of the 12V 80mm x 38mm DC Fan:

• Dimensions: 80mm x 38mm (Diameter x Thickness)

• Input Voltage: 12V

• Power Consumption: ~ 8.4W (12V, 0.7A)

• Duty Cycle 25% - 100%

• Volumetric Flow Rates: ~30CFM - 75CFM

• Fairly noisy at high RPM (duty cycle 100%, 5500RPM, roughly 50dBA)