Membrane flow resistance of unit area is defined as the measure of the resistance that a membrane presents to the flow of a substance through it, normalized by the area of the membrane. And is denoted by Rm. Membrane Flow Resistance of Unit Area is usually measured using the 1 per Meter for Reciprocal Length. Note that the value of Membrane Flow Resistance of Unit Area is always negative. Typically, the value of Membrane Flow Resistance of Unit Area is greater than 0.