–(HISPANIC PR WIRE – CONTEXTO LATINO)–Oxygen sensors are critical for keeping gas mileage up and exhaust emissions down in today’s cars, light trucks and vans. Oxygen sensors measure the amount of oxygen remaining in the exhaust after the combustion process, and send a small voltage signal back to the vehicle’s engine management computer, which in turn adjusts the air/fuel mix.
“Among all the sensors in the various electronic control systems for today’s engines, the oxygen sensor is the most critical for producing the optimum air/fuel mixture of 14.7-to-1, otherwise known as ‘stoichiometric,'” notes Chuck Ruth, director of Product Management, Engine Management Products for Robert Bosch’s Automotive Aftermarket Division. “Other sensors can keep the engine running when the oxygen sensor needs replacement, but the computer can only ‘guess’ at the air-fuel mixture without a properly functioning oxygen sensor.”
Bosch developed the first automotive oxygen sensor for a 1976 Volvo, based on a gas-tight ceramic electrolyte “thimble, which projects into the exhaust stream. A high reading of 0.9 volts indicates excess fuel in the exhaust, while a low reading of 0.2 volts indicates too much oxygen, or not enough fuel.
Research indicates that as many as one out of every seven vehicles on the road needs a new oxygen sensor. If all those sensors were replaced, it would reduce automotive emissions dramatically, save an estimated 3 billion gallons of fuel every year, and improve driving pleasure and efficiency for millions of motorists, Ruth says.
The first oxygen sensors relied on heat from the exhaust to reach operating temperature, and are now known as “unheated thimble” oxygen sensors. Because the warm-up cycle of an engine produces the most exhaust emissions, Bosch developed the “heated thimble oxygen sensor,” which uses electrical heating to bring the sensor up to operating temperature in less than a minute. The heated thimble sensor has since become the standard for most automobiles and light trucks around the world.
More stringent exhaust emission requirements in the mid-1990s led to the development of “heated planar sensors,” which deliver a reading within 12 seconds after an engine is started, and feature a flat, ceramic-zirconia element projecting into the exhaust stream. First introduced on the 1998 Volkswagen Beetle, planar sensors now account for almost 50 percent of oxygen sensors installed in new vehicles in the United States. Further advancements have led to the development of the “heated wide-band oxygen sensor,” which allows even greater refinements in the fuel/air mixture — and more efficient vehicles.
Bosch supplies all four kinds of oxygen sensors: unheated thimble, heated thimble, heated planar and wide-band. “It’s important to recognize that as sensor design and manufacturing technology continues to advance, replacement sensors will often reflect those advancements and may outperform and outlast the original,” says Ruth. “As sensor technology advances, driving efficiency advances with it.”
For more information, visit Robert Bosch at http://www.boschusa.com.