O2 Sensor question,
11-26-2006, 07:53 PM
#1
O2 Sensor question, Quick question for someone that knows alot about O2 sensors.
Where dose the sensor get its comparison reading for the ambient 02? Dose it come in from the back side of the sensor?
The reason I ask is that you see most sensors have a mesh type of conduit over the wires vs a heat shrink type of material. Would there be any problem with the the heat shrink also encapsulating the back of the sensor to add a bit more strength to the wire harness.
The reason I ask is that I had to extend the harness and did just that used a heat shrink tubing and ran it up on the back side of the sensor housing. Have not had a chance to see the o2s in action yet. Just got to thinking after all was said and done.
Where dose the sensor get its comparison reading for the ambient 02? Dose it come in from the back side of the sensor?
The reason I ask is that you see most sensors have a mesh type of conduit over the wires vs a heat shrink type of material. Would there be any problem with the the heat shrink also encapsulating the back of the sensor to add a bit more strength to the wire harness.
The reason I ask is that I had to extend the harness and did just that used a heat shrink tubing and ran it up on the back side of the sensor housing. Have not had a chance to see the o2s in action yet. Just got to thinking after all was said and done.
11-26-2006, 10:06 PM
#2
I copied this from the book "how to tune and modify engine management systems" by Jeff Hartman. It's an excellent read if your gonna tune your own car. I'm sure you'll be fine with what u've done though. I've extended my 02's before. It seems the sensor is vented on the back side of the housing, so just make sure to not block it completely.
"The 02 sensor used in most cars is a voltage-generating sensor that can be thought of as a sort of "air battery". In the lead acid batter used to start a car, an acid medium induces a current flow between two dissimilar metals, freeing energy stored in the acid. The chemical composition of the medium changes as the batter discharges, affecting the output or voltage of the battery. One could, therefore, deduce the chemical composition of the acid (state of charge) based on the output voltage of the battery. In a similar way, the tip of the 02 has a zirconium ceramic bulb coated with porous platinum on the inside and on the outside. The coated inside and outside serve as the electrodes of the air battery. The bulb contains two platinum electrodes and is vented through the sensor housing to the outside atmosphere. When the bulb is exposed to hot exhaust, the difference in oxygen levels across the bulb creates a voltage.
The zirconium-dioxide element in the tip of an 02 sensor thus produces an electrical voltage that varies according to the difference in oxygen content between the atmosphere and the exhaust gases. The sensor can generate as much as approximately .9 volts when the fuel mixture is rich. When the mixture is lean, the sensors output voltage can drop to as low as .1 volts. When the air/fuel mixture is chemically balanced (about 14.7:1) prior to the combustion, the exhaust gas oxygen sensor will generate about .45 volts."
"The 02 sensor used in most cars is a voltage-generating sensor that can be thought of as a sort of "air battery". In the lead acid batter used to start a car, an acid medium induces a current flow between two dissimilar metals, freeing energy stored in the acid. The chemical composition of the medium changes as the batter discharges, affecting the output or voltage of the battery. One could, therefore, deduce the chemical composition of the acid (state of charge) based on the output voltage of the battery. In a similar way, the tip of the 02 has a zirconium ceramic bulb coated with porous platinum on the inside and on the outside. The coated inside and outside serve as the electrodes of the air battery. The bulb contains two platinum electrodes and is vented through the sensor housing to the outside atmosphere. When the bulb is exposed to hot exhaust, the difference in oxygen levels across the bulb creates a voltage.
The zirconium-dioxide element in the tip of an 02 sensor thus produces an electrical voltage that varies according to the difference in oxygen content between the atmosphere and the exhaust gases. The sensor can generate as much as approximately .9 volts when the fuel mixture is rich. When the mixture is lean, the sensors output voltage can drop to as low as .1 volts. When the air/fuel mixture is chemically balanced (about 14.7:1) prior to the combustion, the exhaust gas oxygen sensor will generate about .45 volts."
Last edited by Xtnct00WS6; 11-26-2006 at 10:14 PM.