INSTRUMENT FOR MEASURING CONCENTRATION OF ALCOHOL FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To exactly measure the concn. of alcohol over a long period of time by impressing a voltage to the electrodes of an alcohol sensor for a prescribed period of time. CONSTITUTION:The voltage is impressed from a power source to a pair of the electrodes provided in the alcohol-mixed fuel G of a fuel tank 18 to be supplied to an internal combustion engine 11 and the concn. of the alcohol in the fuel G between the electrodes is measured 23. One end of a fuel piping 20 is connected to a fuel pump 19 and the other end to an injection valve 12 and the alcohol sensor 23 is provided to the intermediate point. A program for processing the voltage impression and a timer are stored in the memory circuit of an arithmetic unit 23 to control the voltage impression in such a manner as to impress the voltage for the prescribed time necessary for the measurement for the specified period of time from the operation of the engine 11 and to stop the impression. The concn. of the exhaust gas of the engine 11 is detected by an oxygen sensor 17 during the stop of the impression. The voltage is impressed to the electrodes when decision is made that the output value changes. The concn. of the alcohol is then measured.