Convert ppb per degree Fahrenheit to ppm per kelvin
Convert ppb per degree Fahrenheit (ppb/°F) to ppm per kelvin (ppm/K) instantly and accurately.
Conversion Formula
ppm/K = ppb/°F × 0.0018
About ppb per degree Fahrenheit
The ppb/°F equals 9/5 × 10⁻⁹ /K ≈1.8 × 10⁻⁹ /K, the Fahrenheit counterpart of ppb/K. Used when ultra-low-expansion glass ceramics are characterised in US laboratories using Fahrenheit protocols. Zerodur at ±0.02 ppb/K ≈ ±0.011 ppb/°F. 1 ppb/°F = 9/5 × 10⁻⁹ /K ≈1.8 ppb/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
| ppb per degree Fahrenheit (ppb/°F) | ppm per kelvin (ppm/K) |
|---|---|
| 1 ppb/°F | 0.0018 ppm/K |
| 2 ppb/°F | 0.0036 ppm/K |
| 5 ppb/°F | 0.009 ppm/K |
| 10 ppb/°F | 0.018 ppm/K |
| 25 ppb/°F | 0.045 ppm/K |
| 50 ppb/°F | 0.09 ppm/K |
| 100 ppb/°F | 0.18 ppm/K |