I read recently about a new type of O2 sensor that is coming on the market called a Wide Range Air/Fuel (WRAF) sensor. The output is a bi-directional current (up to about 20 ma); the direction of the current indicates whether the mixture is rich or lean, and the value of the current gives the air/fuel ratio directly. There are no more rapid voltage swings as in the old O2 sensors.
The advantage of the WRAF sensor is that it covers a wider range of A/F ratios and, more importantly, has an extremely rapid response to the A/F ratio.
What caught my eye is the following quote from an article whose link I'll give below:
Quote:
|
Instead of giving a simple rich/lean indication, wide ratio air/fuel sensors measure the “actual” air/fuel ratio. A WRAF sensor can measure mixtures that range from extremely rich to extremely lean (even straight air!). This ability allows the PCM to control fuel mixtures much more precisely, to handle much leaner fuel mixtures, to reduce emissions and to improve fuel economy compared to ordinary switching O2 sensors. WRAF sensors react much faster than ordinary O2 sensors, which allows them to monitor the fuel mixture from individual cylinders as each puff of exhaust blows by the sensor element. The PCM can then adjust the mixture for each cylinder individually to reduce emissions and optimize fuel economy.
|
That knocked my sox off.
The above quote is from:
Oxygen Sensors: Are You Up to Date on the Latest Designs?
Another good discussion on the WRAF sensor is at:
Wide Range Air/Fuel (WRAF) Sensors
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
