A transient method of measuring the water vapour permeability of packaging films I. Dynamic performance of a sorptive sensor

✍ Scribed by Stefan Doroszewicz

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 596 KB
• Volume: 9
• Category: Article
• ISSN: 0894-3214
• DOI: 10.1002/(sici)1099-1522(199601)9:1<43::aid-pts52>3.0.co;2-q

✦ Synopsis

Principles o f an analysis o f t h e inertia o f a sorptive sensor used for transient measurements of water vapour permeability through packaging films have been developed. The construction of t h e measuring cell and t h e method of measurement o f water vapour permeation through packaging films have been readjusted t o t h e developed principles. It is shown t h a t t h e inertia o f a sorptive sensor, defined as a difference A between measured signal value RH" and an estimated value o f air relative humidity RHI close t o the film surface in an input chamber can be described as a difference of exponential functions A = RHo.[exp(-Ar) -exp (-Br)]. The characteristic parameter determining the sensor inertia is t h e maximum delay time r,; the roots o f t h e funct i o n A(T) derivative. The theory and procedure for using 7, f o r t h e iterative determination of water vapour permeability through packaging films based on analysis of t h e sorptive sensor inertia is presented.