Measurement method of a fuel-air mixture - uses an oxygen sensor in the exhaust gas flow

摘要

The method is intended for i.c. engines, and the sensor delivers an electric switching signal at a certain composition of the fuel-air mixture or of the exhaust gases, result of the fuel-air mixture combustion. A part of the exhaust gases is separated from the main flow, and a reducing and/or oxidising gas is mixed with it until the sensor delivers its signal. The quantity of the reducing and/or oxidising gas is measured. The quantity of the added gas at the moment of signal delivery is the measure for te fuel-air mixture composition. Before the above gas is added, the fuel-air mixture is tested for being rich or poor, and reducing or oxidising gas is added in accordance with oxygen sensor output signal.