An electrochemical sensor for distinguishing two-stroke-engine oils

Abstract

An electrochemical sensor, which is composed of two gold-plated iron electrodes, was developed to distinguish two-stroke-engine oils from four-stroke-engine oils, so that the catalytical converter on a two-stroke-engine car would not be poisoned by the antiwear agents (zinc organodithiophosphates or ZDP's) or metallo-organic detergents (such as calcium sulfonates) existing in four-stroke-engine oils. The sensor has demonstrated its capability in detecting metallo-organic detergents, ZDP's, and ashless detergents. At 23 and 50°C, the sensor outputs obtained from the four-stroke-engine oils are much higher than those from the two-stroke-engine oils (with the exception of Pro-Series and Yamalube). High sensor outputs obtained from Pro-Series and Yamalube are due to the addition of an ashless detergent, amide, in these two-stroke-engine oils. Therefore, the sensor has the potential of distinguishing two-stroke-engine oils; (without ashless detergents) from four-stroke-engine oils and two-stroke-engine oils containing ashless detergents. At present, it is not clear whether the ashless detergents would poison the catalytic converter on a two-stroke-engine car.