Cylinder pressure gauge is measuring engine cylinder compression force of tools. When measuring the first to heat engine make water temperature reaches 70-80 °C flameout and measurement. When measuring diesel engine for its compression force big, must the pressure multiplier closely fastening in installation of the injector position can measure. Measuring gas automata compression force is relatively small, usable hand holding the pressure gauge, the direct roof in spark plug hole measurements. The best measure 2 -- 3 times, take its average, and the type of cylinder pressure regulating compared, general gasoline engine shall be not less than 20% of the required standard, shall not be less than 15% of diesel engine standard. Each cylinder pressure between poor: shall not exceed 5%, diesel engine shall not exceed 8 percent.