An injection quantity sensor for automotive applications

For a further optimization of the internal combustion process of automobiles, a miniaturized injection quantity sensor based on the electro-thermal measurement principle was developed. It consists of a thin film metallization of titanium/platinum on a low temperature cofired ceramics (LTCC) substrate. For high-precision fuel quantity measurements, the sensor chip was integrated into a finished common rail diesel injection nozzle. The micro-flow sensor proved its high performance over the complete fuel quantity map of a high pressure hydraulic injection system up to injection pressures of 135 MPa (1350 bar). For the evaluation of the sensor signals, an injection amount indicator integrated into the hydraulic test bench was used.