Perm (unit)
A perm is a unit of permeance or "water vapor transmission" given a certain differential in partial pressures on either side of a material or membrane.
Read more about Perm (unit): Definitions, German Institute For Standardization Unit
Perm (unit)
A perm is a unit of permeance or "water vapor transmission" given a certain differential in partial pressures on either side of a material or membrane.
Read more about Perm (unit): Definitions, German Institute For Standardization Unit