To comply with increasingly stringent targets for emissions and fuel economy, more and more precise mass airflow sensor technology is required on both gasoline and Diesel engines.
On gasoline engines, the mass flow signal is used to more precisely determine engine load. This, in turn, enables more precise fuel metering than can be achieved with traditional indirect load detection methods. The lambda control variations are reduced significantly, and a more precise control of the mixture ratio can be achieved in cases where the lambda probe, i. e., the oxygen sensor, does not yet work perfectly.
On Diesel engines, the mass airflow sensor is used for the most precise automatic and independent control of EGR systems, including even the control of map dependent Diesel injection pumps. Backflow conditions on Diesel engines with four or fewer cylinders, especially in combination with EGR, render normal mass air flow meter sensing inadequate.
This article presents a new type of very fast response Pierburg mass airflow sensor, which is capable of bidirectional flow sensing. The sensor is made by chip technology and has a microprocessor integrated in the hybrid electronics.