Convert ppm per degree Fahrenheit to ppm per kelvin
Convert ppm per degree Fahrenheit (ppm/°F) to ppm per kelvin (ppm/K) instantly and accurately.
Conversion Formula
ppm/K = ppm/°F × 1.8
About ppm per degree Fahrenheit
The ppm/°F (= μin/(in·°F) exactly) equals 9/5 × 10⁻⁶ /K ≈1.8 × 10⁻⁶ /K and is the dominant CTE unit in US ASTM standards, ASME piping codes, and mechanical engineering handbooks. Steel ≈6.7 ppm/°F; aluminium ≈12.8 ppm/°F; copper ≈9.4 ppm/°F. 1 ppm/°F = 9/5 × 10⁻⁶ /K.
About ppm per kelvin
The ppm/K (= μm/(m·K) exactly) equals 10⁻⁶ /K and is the universal CTE unit in international materials standards (ISO, EN, DIN). Aluminium: 23.1 ppm/K; steel: ≈12 ppm/K; ordinary glass: ≈9 ppm/K; fused silica: 0.55 ppm/K; Invar: ≈1.2 ppm/K. 1 ppm/K = 10⁻⁶ /K.
Quick Reference Table
| ppm per degree Fahrenheit (ppm/°F) | ppm per kelvin (ppm/K) |
|---|---|
| 1 ppm/°F | 1.8 ppm/K |
| 2 ppm/°F | 3.6 ppm/K |
| 5 ppm/°F | 9 ppm/K |
| 10 ppm/°F | 18 ppm/K |
| 25 ppm/°F | 45 ppm/K |
| 50 ppm/°F | 90 ppm/K |
| 100 ppm/°F | 180 ppm/K |