Convert ppm per degree Fahrenheit to ppb per kelvin
Convert ppm per degree Fahrenheit (ppm/°F) to ppb per kelvin (ppb/K) instantly and accurately.
Conversion Formula
ppb/K = ppm/°F × 1800
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 ppb per kelvin
The ppb/K (parts per billion per kelvin) equals 10⁻⁹ /K and is the resolution unit for ultra-low-CTE materials. Zerodur Class 0 (±0.02 ppb/K) and ULE titanium-silicate glass (±0.03 ppb/K) at 20 °C are characterised in ppb/K for gravitational-wave interferometers and space telescope optical benches. 1 ppb/K = 10⁻⁹ /K = 10⁻³ ppm/K.
Quick Reference Table
| ppm per degree Fahrenheit (ppm/°F) | ppb per kelvin (ppb/K) |
|---|---|
| 1 ppm/°F | 1800 ppb/K |
| 2 ppm/°F | 3600 ppb/K |
| 5 ppm/°F | 9000 ppb/K |
| 10 ppm/°F | 18000 ppb/K |
| 25 ppm/°F | 45000 ppb/K |
| 50 ppm/°F | 90000 ppb/K |
| 100 ppm/°F | 180000 ppb/K |