The electric heater operates under rated voltage conditions, tests changes in heater power, current, and temperature, outputs different data through changes in voltage, air volume, or working environment, and finally forms a data description curve. It can clearly understand the power and temperature changes of the product under specific working conditions, and the data can guide the design, so as to design the product within a reliable service life range and avoid extreme parameter design; And there is a lifespan deduction for analyzing product design.