The Oxygen Transmission Rate Tester (Oxygen Permeability Tester / OTR Tester) measures oxygen transmission rate (OTR) and oxygen barrier performance of films, sheets, laminates, bottles, pouches, cans and other packaging materials under controlled temperature and humidity, using equal-pressure (coulometric) or differential-pressure methods. It supports ASTM D3985, ISO 15105-1/-2, GB/T 19789 and optional YBB standards, and is widely used in food, pharmaceutical, medical device, personal care, electronics and new energy industries for R&D, QC and shelf-life evaluation.