A Fast Light Off Thimble-type Oxygen Sensor

The largest portion of hydrocarbon and/or carbon monoxide emissions is released during engine cold-transient operation. To achieve closed loop control as quickly as possible, a fast light off (FLO) oxygen sensor is required. The heater, element and structure of the thimble-type oxygen sensor that has been used in the market for some time has been improved to achieve closed loop control within 15 seconds. The heater is improved by concentrating the heating area and by lowering its resistance. The heater life is similar to that of the current type by using new materials and adopting new heater temperature control strategies. In addition to the efficiency of heat transfer, the low temperature characteristics of the element have also been improved. The fast light off thimble-type oxygen sensors can now be put to practical use to achieve emission reductions.