Oxygen sensors

1. Introduction

1.1 The modern oxygen sensor:

Figure 1. The Boch oxygen sensor

Bosch pioneered the discovery of the oxygen sensor within the early 1970’s drawing upon experience inside the era of high temperature ceramics evolved from a few years of spark plug development. The oxygen sensor’s first vehicle application got here in 1976 used on a K-jetronic prepared Volvo 260 series for the californian market. this became the start of one of the maximum widely used emission control devices in automobile records. given that then, Bosch has produced over 500 million oxygen sensors internationally, offering the general public of global car manufacturers. Currently Bosch produces approximately 40 million oxygen sensors consistent with year in plant life positioned in Germany and the us. as a major international developer of automobile technology, Bosch has continually progressed the layout and function of engine management structures to optimize oxygen sensor capability and continuously enhance car exhaust emissions at the same time as enhancing basic car performance. Evolution of the sensor over time has resulted in lots of layout upgrades in each operation and substitute durations. starting as a simple single wire sensor, tendencies encompass the introduction of stepped forward earth circuits, heating factors to stabilize sensor temperature and now “planar” layout sensors delivering superior sensitivity and accuracy as well progressed service existence.

Vehicle emissions are a primary thing within the layout of latest vehicles. Bosch research and development in the vicinity of engine control system and product era has visible the introduction of “broadband” oxygen sensors, imparting expanded scope of operation of the oxygen sensor for manage of combination values outside of the regular control variety. latest years have seen many modifications inside the Australian car marketplace. in early 2006, stringent Euro III vehicle emission standards have been implemented, further assisting within the reduction of dangerous car emissions and greenhouse fuel emissions from motor cars. Due to this requirement, there is a big boom in the quantity of latest motors making use of “Broadband” oxygen sensor era in addition to the implementation of manage (pre catalyst) and prognosis (post catalyst) oxygen sensor device configuration, resulting in an growth in the number of oxygen sensors placed within the automobile. The tracking and feature of the oxygen sensor is now bigger than ever a prime influence in engine management machine operation. Extra focus must be positioned on the ordinary checking out and alternative of faulty oxygen sensors to keep finest car overall performance. diesel powered automobiles now make up about 20% of all new passenger vehicle income. A lot of those modern commonplace rail diesel systems also utilize the latest layout evolution of Bosch “broadband” oxygen sensor, the LSU 4.9 series. these units provide rapid correct information to the engine management machine, are able to resist the distinctive environmental situations skilled with diesel packages as well as presenting superior service life.

2. The working principle of the sensor

2.1 The purpose of the oxygen sensors:

Automotive computer structures use a sensor within the exhaust system to track the oxygen content of the exhaust. These sensors are known as oxygen sensors (O2S). The oxygen sensor is installed within the exhaust manifold or positioned downstream from the manifold inside the exhaust pipe.

Figure 2.1 The location of the oxygen sensor

The majority of the fuel-control oxygen sensors are placed in the exhaust manifold near its outlet so that the sensor can discover the presence or absence of oxygen in the exhaust stream for all cylinders that feed into the manifold

The oxygen sensor is placed within the course of the exhaust fuel movement, where it detects oxygen degree in both the exhaust circulation and the ambient air. In a zirconia oxygen sensor, the end carries a thimble fabricated from zirconium dioxide (ZrO 2 ), an electrically conductive material able to generating a small voltage within the presence of oxygen. The oxygen sensor is utilized by the PCM to control distribution.