What is the exact volume equivalence of the Iraqi Ratl used in defining the Sa'?

Primary text

The Iraqi Ratl was historically equivalent to one hundred and twenty-eight and four-sevenths dirhams, which equates to ninety mithqals. Subsequently, an addition was made, making it ninety-one mithqals, resulting in one hundred and thirty dirhams, intended to eliminate fractional dirhams. The ruling adheres to the initial, historical measure, as this was prevalent when scholars defined the Mudd. Consequently, the Mudd is one hundred and seventy-one and three-sevenths dirhams, corresponding to the Damascene Ratl, which weighs six hundred dirhams (three uncias and three-sevenths of an uncia). Thus, the Sa' is four Amdad, equal to one ratl, one uncia, and five-sevenths of an uncia.