Lambda Measurement

What is Lambda?

Lambda is a measure for the mass air to fuel ratio (AFR) present during combustion. When exactly enough fuel is combined with the available free oxygen, the mixture is chemically balanced and is called stoichiometric.

  • Lambda = 1 —stoichiometric mixture

  • Lambda < 1 —mixture is rich, excess fuel present 

  • Lambda > 1 —mixture is lean, excess air present

The amount of air that is needed depends on the type of fuel used. In the case of gasoline/petrol, a stoichiometric mixture consists of an air to fuel ratio of 14.7 to 1. For different fuel, different ratios apply.

Narrowband Lambda

Narrowband Lambda is a measurement method where the AFR range is limited from 14:1 to 15.4:1. The sensor reading switches very sharply between the thresholds of lean and rich areas, providing a signal which indicates either a rich or a lean mixture but not to what degree.

This works well in controlling an engine for emissions, however, the limited range makes narrowband Lambda unsuitable for accurate tuning.

Wideband Lambda

Wideband Lambda sensors are designed to give an exact reading of Lambda. This is particularly useful when the precise mixture needs to be known in order to tune the engine for optimum power. The measuring range can span from 0.7 to 32 Lambda for a 5 wire sensor type. 
Wideband Lambda sensors use sophisticated controls, as the temperature change needs to be taken into account to be accurate.


4 item(s) - Page 1 of 1
MoTeC Lambda to CAN Module
Product ID : JRR LTC
MoTeC Lambda to CAN Module - NTK
Product ID : JRR LTC NTK
MoTeC Lambda to CAN Module - Dual Channel
Product ID : JRR LTC-D
MoTeC Lambda to CAN Module - NTK Dual Channel
Product ID : JRR LTC-D NTK