A construction vehicle includes an engine, a hydraulic pump driven by the engine, a travel hydraulic motor driven by pressure oil discharged from the hydraulic pump, travel wheels driven by the drive force of the travel hydraulic motor, and a controller. It has been discovered that H2 evolution can significantly improve the performance of air cathodes and direct methanol fuel cell anodes. A second sound signal indicates a resulting sound signal after deletion of the second kind of sound signals from the first sound signal. Information is collected and processed over time while samples are subjected to selected temperature environments to provide a data base of adhesion characteristics of thin films and coatings.