188.8.131.52. The sensor of concentration of oxygen (with heating)
The control unit to engines uses signals of the oxygen sensor for the regulation of structure of a topli-vno-air mix providing optimum fuel profitability and decrease in harmful emissions. According to information on the content of oxygen in the fulfilled gases, arriving from the forward oxygen sensor, extent of enrichment or pauperization of the fuel and air mix submitted to cylinders of the engine is defined. Efficiency of catalytic converter of the fulfilled gases is determined by signals from the back oxygen sensor. EBU calculates efficiency of converter by signal comparison from the back oxygen sensor with a signal from the forward sensor.
Normal tension of a signal of the oxygen sensor constantly changes about value 500 мВ, and frequency of a signal of the forward sensor makes not less than 5 Hz at 2500 mines-1. As a result of effect of catalytic converter frequency of a signal of the back oxygen sensor is lower, than frequency of a signal of the forward oxygen sensor. If frequency of a signal of the back oxygen sensor during a wide interval of time coincides with frequency of a signal of the forward oxygen sensor, it indicates decrease in efficiency of catalytic converter or on malfunction of a power supply system of the engine.
|Fig. 2.248. The scheme of connections of the sensor of concentration of oxygen with EBU