220 Sum of fractions

The sum of fractions clay, silt and sand should be 100% (by mass).

The system accepts an error of 1% per fraction, so a sum between 97 and 103% will be accepted.

When correcting the percentage of fractions to end up with a sum of exactly 100%, please do so by adopting the largest fraction.

Example:

• clay = 6%
• silt = 58%
• sand = 35%

-> sum = 99%

Adopt silt (here largest fraction) to 59% to achieve a sum of 100%:

• clay = 6%
• silt = 59%
• sand = 35%

-> sum = 100%

The rationale is that 1% error on the smallest fraction (mostly clay) has a larger impact then on the largest fraction, when the relative error is similar for each fraction.