The paper deals with the basic principles of use and testing of the new method for measuring injected volumes of liquids. The
above method was employed in measuring the injected fuel volume in diesel injection systems, where fuel is injected at time
intervals of up to 4 ms. It works by measuring the electric charge deposited by liquid droplets impacting a metal electrode. The
electric charge is generated mainly in the injection nozzle, where the fuel rubs against the metal parts of injection nozzle, resulting
in one portion of free electrons moving from the metal to the fuel. The fuel then transfers this electric charge to the sensor electrode.
Rubbing merely serves to bring many points of the surface into good contact. The electric current appears also due to the temperature
gradient in the sensor electrode. The temperature gradient in the electrode is a result of the transformation into heat of kinetic
energy of fuel droplets hitting the electrode at velocities of 100–300 m s-1. The electric charge is led from the electrode to the
charge amplifier, where it is converted into electric current. The test results showed a very reliable operation of the sensor and a
linear dependence of the area under the injection rate curve upon the injected fuel volume. The comparison of the injected rates
measured with the charge and Bosch measuring method, which is most frequently utilised today, showed a good matching of results
in any operating regime.