Accelerated Life Testing (ALT) Foundations
ALT applies elevated thermal, voltage, or humidity stresses to compress months of physical wear into days of laboratory chamber testing without altering the underlying failure physics.
Intermediate Category: Reliability Analysis • ~5 min read
Accelerated Life Test (ALT) Planner
Calculate acceleration factors (AF) and shorten life test durations under elevated stress.
Q:
How does Arrhenius thermal acceleration work in ALT?
The Arrhenius acceleration factor AF scales chemical and thermal degradation rates with temperature: AF = exp[(Ea / kB) · (1/Tuse - 1/Tstress)], where Ea is activation energy (eV), kB = 8.617 × 10⁻⁵ eV/K, and temperatures are in Kelvin. A target 50,000-hour field life tested at AF = 25× requires only 2,000 chamber test hours.
Acceleration Model
Typical: 0.7 eV (electronics), 0.3-0.5 eV (mechanical)
Total Acceleration Factor (AF)
61.25×
1 test hr = 61.25 field hrs
Required Chamber Test Time
408.2 h
17.0 days
Zero-Failure Sample Size (n)
45 units
At 90% conf, 95% rel
Acceleration Factor Factorization
Arrhenius Thermal AF:
61.25×
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Engineering & Regulatory Notice: The calculations, projections, and failure models provided in this suite are for engineering estimation and educational purposes. Verify all calculations and assumptions independently before making operational, equipment replacement, safety-critical, or regulatory compliance decisions.
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