O2 Sensors, Design

O2 Sensors, Design
Finger Sensor




1 Electrical connection
2 Sensor housing
3 Active ceramic probe body
4 Electrode (inner)
5 Electrode (outer)
6 Heating element
7 Inner, open combustion chamber
8 Protective tube
9 View of electrical connection for O2sensor
1 Sensor heater
2 Sensor heater ground
3 O2 sensor signal ground
4 O2 sensor signal
G3/1 O2 sensor downstream of TWC
G3/2 O2 sensor upstream of TWC
G3/3 Left O2 sensor upstream of TWC
G3/4 Right O2 sensor upstream of TWC
G3/5 Left O2 sensor downstream of TWC
G3/6 Right O2sensor downstream of TWC

Voltage-free insulated O2 sensors are used.
The active sensor ceramic consists of a gas-permeable ceramic body manufactured from zirconium dioxide. A protective tube with several slots protects the ceramic body from mechanical stresses and from temperature jumps.
The eletrical connection is performed by means of a 4-pin connector.
The capacity of the sensor heater at operating temperature is:
- 18 W (engines with ME 1.0, 2.0, 2,1)
- 7 W (engine 112, 113 with ME 2.8, engine 137).