A composite material having a laminated film is disclosed in which between two or more photocatalyst layers each possessing a light permeability an a photocatalytic reactivity middle layers composed of a light permeable material having a reflectance different from that of the photocatalyst layers are interposed, laminated on a base material surface. The subject arrangement 22 is useful in both high and low dust environments to mitigate ash and like particulate accumulation on reducing agent nozzles 42 and to provide more uniform reducing agent flow distribution upstream of the SCR reactor 18. A tank is mounted on the chassis for holding liquid to be sprayed. The processor, responsive to the processor interrupt signal, measures the acceleration with higher accuracy than the motion detector is capable of, but in a way that consumes more power than was needed by the motion detector.