The GT-N20 Roughness and Air Permeability Tester is a high-precision laboratory analyzer designed to measure surface roughness and air permeability across a diverse range of technical substrates. Engineered to perform the standardized Bendtsen method, this equipment natively calculates Gurley Porosity equivalents directly from measured flow values. It guarantees full compliance with global standards including ISO 8791, ISO 5636 and DIN 53120.