Home > Engine Controls > Emissions Control > Air/Fuel Control Introduction
Introduction to Air/Fuel Ratio Control
The Gill air/fuel ratio control system provides cost effective emissions control for gaseous fuelled engines used in demanding industrial applications.
The system is designed to accurately control the air/fuel ratio of stoichiometric engines fitted with a three way catalytic converter, and lean burn engines with or without a cat.
- Automatically controls optimum air/fuel ratio
- Reduces engine emissions
- Prolongs catalyst life
- Improves engine efficiency
- No need for constant manual engine tuning
The Gill AF120 system uses a wide band oxygen sensor (UGEO) that provides a consistent linear output, in relation to percentage of oxygen in an engine’s exhaust. This provides accurate measurement from very fuel rich air/fuel mixtures up to 21% Oxygen concentration (Atmospheric concentration) – see graph below. This sensor can be used in both stoichiometric and lean burn configurations and allows the use of proportional control systems.

As the UEGO sensor provides such an accurate measurement of the oxygen concentration, for example when an engine experiences a change in load, the AF120 system is able to measure the change in O2 and make adjustments to the valve position accordingly leading to a faster and more accurate response to load steps. Engines using the Gill AF120 system have shown that the system is capable of keeping an engine’s emissions below strict requirements, such as those in California, for over six months, without the operator making changes to the engine - a major improvement over older narrow band systems.
Typical Applications
- CHP Engines
- Generator Set Engines
- Compressor Engines
- Commercial Vehicle Engines
- Fork Lift Truck Engines
|