Lambda Sensor

[4lec]

I know that lots of modern engines have Lambda Sensors. Does anyone know why they were called "Lambda"? Is it just coincidence that it is a physics term for wavelength aswell or was there a logical explanation between them?
thanks
alec

[Toureman]

The only thing I have found so far is that it is the eleventh letter in the Greek alphabet!

[KebabMeister]

AFAIK it was Volvo who first started using the term Lambda. Most other manufacturers just call them Oxygen Sensors.

[kempie]

The first lambda probes (precursor of the lambda sensor) were produced by Bosch.

Lambda is used in chemistry for stoichiometry (ratio of chemicals or reactants) such as that of the fuel/air mix measured in the exhaustpipe.

When lambda equals one, you have a 14.7:1 stoichiometric air/fuel ratio and ideal combustion.

When the air/fuel ratio is greater than 14.7:1, lambda also will be greater than one and the engine will have a lean mixture.

Likewise when lambda is less than one the engine will have a fuel rich mixture.

http://www.forparts.com/BoswidebandO2.htm

[KebabMeister]

Those clever Bosch people... iirc they also invented the Anti Blockier System (ABS).