fuel injection technology Active Flow Meter for GDI injector test


The active flow meter (AFM) developed by Sonplas is an innovative assembly efficiently combining two disciplines – high pressure generation and flow measurement – for flow measurement of the injector. During conventional flow metering of fuel injectors, the supply pressure is generated by a rotating pump, and is permanently available – regardless of whether it is needed or not. This pump feeds a comparatively complex hydraulic circuit, and supplies the test object in the process. In this configuration, the mass flow through the injector must be recorded by an external sensitive measurement system.

The Sonplas AFM replaces the inefficient high pressure pump and additional measurement system, while it allows the generation of a minimal and – in comparison to the traditional flow measurement – efficient, and thus environmentally friendlier hydraulic circuit for the supply of the injector.

The principle of the active flow meter is very simple: A hydraulic cylinder pushes a test medium through the injector. Knowing the stroke volume and the boundary conditions allows a precise statement to be made about the injector flow.


  • Up to 97% less energy consumption in comparison with conventional technology
  • Pressure generation and flow measurement combined in one system
  • The pump design can be used for flow and leak tests
  • Sturdy construction
  • Easy and low cost maintenance
  • Enhanced system availability
  • Minimal space requirement
  • Optional retrofitting in existing systems available
  • Low noise emission
  • Optional self-diagnosis and maintenance prediction available

Technical data  

  • Pressure range of up to 1000 bar
  • Flow range: 1.0 mg/shot to 150 mg/shot
  • Scalable cylinder volume