Patent ID: 7587288
Filing Date: 2009-09-08
Classification: F01N,G01N,Y02A,Y02T

Abstract:
1. A liquid reducing agent discriminating apparatus comprising: a sensor disposed in a storage tank capable of storing a liquid reducing agent and configured to output a signal in relation to concentration of the liquid reducing agent on the basis of a characteristic of heat transmission between two points apart from each other within the storage tank; and a control unit having therein a computer, wherein the control unit: outputs a measurement trigger at a predetermined time interval after start of an engine; calculates concentration of the liquid reducing agent on the basis of the signal from the sensor when the measurement trigger is outputted; counts each of first number of times that the concentration successively becomes equal to or higher than a predetermined upper limit threshold and second number of times that the concentration successively becomes equal to or lower than a predetermined lower limit threshold; determines that there is no remainder of liquid reducing agent when the first number of times becomes equal to or larger than a predetermined value; and determines that there remains an incorrect solution other than the liquid reducing agent when the second number of times becomes equal to or larger than the predetermined value.