Convert ppm per degree Fahrenheit to Microns per metre per degree Celsius

Convert ppm per degree Fahrenheit (ppm/°F) to Microns per metre per degree Celsius (μm/(m·°C)) instantly and accurately.

ppm per degree Fahrenheit (ppm/°F)
Microns per metre per degree Celsius (μm/(m·°C))

Conversion Formula

μm/(m·°C) = 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 Microns per metre per degree Celsius

The micrometre per metre per degree Celsius (μm/(m·°C)) equals exactly 10⁻⁶ /K, since temperature intervals 1 °C = 1 K (exact). It is the standard CTE notation in European engineering datasheets, ISO material standards, and many textbooks. Numerically identical to ppm/K. Aluminium: 23.1 μm/(m·°C); steel: ≈12 μm/(m·°C). 1 μm/(m·°C) = 1 ppm/K = 10⁻⁶ /K.

Quick Reference Table

ppm per degree Fahrenheit (ppm/°F)Microns per metre per degree Celsius (μm/(m·°C))
1 ppm/°F1.8 μm/(m·°C)
2 ppm/°F3.6 μm/(m·°C)
5 ppm/°F9 μm/(m·°C)
10 ppm/°F18 μm/(m·°C)
25 ppm/°F45 μm/(m·°C)
50 ppm/°F90 μm/(m·°C)
100 ppm/°F180 μm/(m·°C)

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