Patent ID: 9708952
Date: 2017-07-18
CPC Classifications: B01D,F01N,G01N,Y02A,Y02T

Claim:
1. A diagnostic device for a urea water supply system having a sensor for detecting a concentration of urea water, the diagnostic device comprising: an acquisition section that acquires a detected value of the sensor; a calculation section that calculates a NOx purification rate by a selective reduction catalyst; and a diagnosis section that diagnoses a state of the urea water supply system, wherein the diagnosis section is adapted to diagnose that the sensor is abnormal when only one of a first condition and a second condition is satisfied, where the first condition is that the purification rate calculated by the calculation section is greater than or equal to a reference purification rate, and the second condition is that the detected value acquired by the acquisition section is greater than or equal to a reference concentration.