HiBarSens: Measurement of barrier properties by tunable diode laser absorption spectroscopy (TDLAS)

摘要

Organic electronic products require ultra-high barrier materials and an adequatemetrology for barrier quality guarantee with water vapor transmission rates (WVTR)better than 10~(-4) g m~(-2) d~(-1). Tunable diode laser absorption spectroscopy is a selective,highly sensitive non-invasive moisture sensor that has been applied to meet thesedemands. Two different methods – the isostatic mode (carrier gas) and the quasiisostaticmode (accumulation) are compared in one setup and the results arediscussed. Thus different interference effects have been identified and there influenceon ultra-low permeation measurement was reviewed. As a result a new technologywith diffusion controlled transport of the permeate and consequently higher moistureconcentrations at the sensor site is shown for a reliable detection of ultra-low watervapor transmission rates.