Bernoulli’s Principle


Bernoulli’s principle describes the relationship between the flow velocity of a fluid and its pressure. An increase in velocity leads to a reduction in static pressure in a flowing fluid, and vice versa. The total pressure of the fluid remains constant. Bernoulli’s equation is also known as the principle of conservation of energy of the flow.

The FM 100.02 experimental unit is used to demonstrate Bernoulli’s principle by determining the pressures in a Venturi nozzle. The experimental unit includes a pipe section with a transparent Venturi nozzle and a movable Pitot tube for measuring the total pressure. The Pitot tube is located within the Venturi nozzle, where it is displaced axially. The position of the Pitot tube can be observed through the Venturi nozzle’s transparent front panel. The Venturi nozzle is equipped with pressure measuring points to determine the static pressures. The pressures are displayed on the six tube manometers.

The total pressure is measured by the Pitot tube and displayed on another single tube manometer. The experimental unit is positioned easily and securely on the work surface of the HM 150 base module. The water is supplied and the flow rate measured by FM 100. Alternatively, the experimental unit can be operated by the laboratory supply.


  1. Familiarization with Bernoulli’s principle
  2. Venturi nozzle with transparent front panel and measuring points for measuring the static pressures
  3. Axially movable Pitot tube for determining the total pressure at various points within the Venturi nozzle
  4. 6 tube manometers for displaying the static pressures
  5. Single tube manometer for displaying the total pressure
  6. Flow rate determined by FM 100 base module
  7. Water supply using FM 100 base module or via laboratory supply

Technical Details

  1. Venturi nozzle
  2. A: 84…338mm2
  3. Angle at the inlet: 10,5°
  4. Angle at the outlet: 4°
  5. Pitot tube
  6. Movable range: 0…200mm
  7. Ø 4mm
  8. Pipes and pipe connectors: PVC

Measuring ranges:

  • Pressure 0…290mmWC (static pressure) 0…370mmWC (total pressure)