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

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

ppm per degree Fahrenheit (ppm/°F)
Millimetres per metre per degree Celsius (mm/(m·°C))

Conversion Formula

mm/(m·°C) = ppm/°F × 0.0018

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 Millimetres per metre per degree Celsius

The millimetre per metre per degree Celsius (mm/(m·°C)) equals exactly 10⁻³ /K = 1 mm/(m·K), since temperature intervals 1 °C = 1 K (exact). Used in European structural engineering, EN standards, and civil/mechanical design codes for expansion joint sizing. Steel rail: 0.012 mm/(m·°C); aluminium curtain wall: 0.023 mm/(m·°C). 1 mm/(m·°C) = 10⁻³ /K = 1 mm/(m·K).

Quick Reference Table

ppm per degree Fahrenheit (ppm/°F)Millimetres per metre per degree Celsius (mm/(m·°C))
1 ppm/°F0.0018 mm/(m·°C)
2 ppm/°F0.0036 mm/(m·°C)
5 ppm/°F0.009 mm/(m·°C)
10 ppm/°F0.018 mm/(m·°C)
25 ppm/°F0.045 mm/(m·°C)
50 ppm/°F0.09 mm/(m·°C)
100 ppm/°F0.18 mm/(m·°C)

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