udunits/src/main/java/ucar/units/ScaledUnit.java
public double fromDerivedUnit(final double amount)
            throws ConversionException {
        if (!(_unit instanceof DerivableUnit)) {
            throw new ConversionException(getDerivedUnit(), this);
        }
        return ((DerivableUnit) getUnit()).fromDerivedUnit(amount) / getScale();
    }
public double fromDerivedUnit(final double amount)
            throws ConversionException {
        if (!(_unit instanceof DerivableUnit)) {
            throw new ConversionException(getDerivedUnit(), this);
        }
        return ((DerivableUnit) getUnit()).fromDerivedUnit(amount) / getScale();
    }
Converts a numeric value from the underlying derived unit to this unit.

@param amount
The numeric value in the underlying derived unit.
@return The equivalent value in this unit.
@throws ConversionException
Can't convert value.