UREA CONCENTRATION IDENTIFYING SYSTEM, METHOD FOR IDENTIFYING UREA CONCENTRATION AND AUTOMOBILE EXHAUST GAS REDUCING SYSTEM USING SAME, AND METHOD FOR REDUCING AUTOMOBILE EXHAUST GAS

摘要

The concentration of the urea of a urea solution is identified accurately and immediately. A pulse voltage is applied for a predetermined time to a urea concentration identifying sensor heater including a heater and an identifying liquid temperature sensor provided in the vicinity of the heater, a urea solution to be identified is heated by the heater, and the concentration of the urea is identified with a voltage output difference V0 corresponding to a temperature difference between an initial temperature and a peak temperature in the identifying liquid temperature sensor.