Converter
logarithmic particle-size scale
phi grain-size scale
exact
- Record
- M663
- Definition quality
- Historically documented
- Conversion mode
- formula
- Calculator
- Formula-based
Definition
φ = -log2(Dmm); Dmm = 2^-φ.
Reference value
phi grain-size scale converts through a formula rather than a simple multiplier.
Modern use
Modern use is context-dependent and varies by region or measurement system.