Arrhenius Acceleration Factor: The Core of Temperature Acceleration
What is the Arrhenius Model?
The Arrhenius model describes how chemical reaction rate changes with temperature: failure rate rises exponentially with temperature, giving the acceleration factor AF = exp[(Ea/k)(1/Tu − 1/Ts)], where Ea is the activation energy, k is Boltzmann's constant (8.617×10⁻⁵ eV/K), Tu the use temperature and Ts the test temperature, both in kelvin. It is the most common basis for temperature-accelerated testing and assumes a single temperature-driven reaction mechanism; if that assumption fails, another model is needed.
When to Use It
Use it to design high-temperature operating life (HTOL) and high-temperature storage tests, to extrapolate accelerated results to the rated use temperature, and for lifetime assessment of LED lumen depreciation, electrolytic capacitors and semiconductor devices. For temperature cycling or failures not dominated by temperature, switch to other models; the tool notes its applicable range.
How to Use It (Step by Step)
Enter the activation energy, use temperature and test temperature, and the tool returns the acceleration factor AF, the equivalent use hours per test hour, and the equivalent use time for a given test duration. Convert temperatures to kelvin (℃ + 273.15) and review the source of Ea before trusting the result — AF is highly sensitive to both Ea and temperature.
Key Formulas / Example
AF = exp[(Ea/k)(1/Tu − 1/Ts)]. Example: Ea = 0.7 eV with a use temperature of 25 °C and a test temperature of 105 °C gives AF ≈ 300, so 1,000 test hours represent roughly 300,000 use hours. Beware that an excessively high test stress can introduce a new failure mechanism and invalidate the extrapolation.