| 摘要 |
A method and an apparatus for determining the permeation rate of barrier materials, with which in a measuring chamber (8.7) which has at least two shut-off elements (81; 8.2) for opening and closing, a concentration of at least one permeate is determined which, present as a test gas with a constant concentration in a test gas chamber (8.3), is permeated into the measuring chamber (8.7) through a barrier element (8.5) which is arranged between the test gas chamber (8.3) and the measuring chamber (8.7) and which has a known permeable surface (A). In this respect, the permeation rate is calculated using an enriching time (tA) and using a purge time (tS) determined using a first measurement variant in a process step (i) and the course of the permeate concentration (c) determined during the purge time (tS) or using a course of the permeate concentration (c) determined using a second measurement variant in a process step (i) during a predefinable purge time (tvS) and using the predefinable purge time (tvS) and a predefinable enriching time (tvA) using an equation. |
| 主权项 |
1. Method for determining the permeation rate of barrier materials,
wherein in a measuring chamber (8.7) which has at least two shut-off elements (8.1; 8.2) for opening and closing, a concentration of at least one permeate is determined which, present as a test gas with a constant concentration in a test gas chamber (8.3), is permeated into the measuring chamber (8.7) through a barrier element (8.5) which is arranged between the test gas chamber (8.3) and the measuring chamber (8.7) and which has a known permeable surface (A); wherein in a process step (i), the measuring chamber (8.7) is purged with a constant permeate-free purge gas volume flow ({dot over (V)}) by opening the shut-off elements (8.1; 8.2) once a predefinable upper switchover concentration (cvA) has been reached in a first measurement variant or once a predefinable enriching time (tvA) has been reached in the second measuring variant; wherein the permeate concentration (c) in the open measuring chamber (8.7) drops as a result of the purging; and the time course of this permeate concentration (c) is either determined up to the reaching of a predefinable lower switchover concentration (cvS) in the first measurement variant, with a purge time (tS) being determined in this respect, or up to the reaching of a predefinable purge time (tvS) in the second measurement variant; and in a process step (ii), on reaching the predefinable lower switchover concentration (cvS) in the first measurement variant or on reaching the predefinable purge time (tvS) in the second measurement variant, the measuring chamber (8.7) is closed by closing the shut-off elements (8.1; 8.2), with the permeate concentration (c) increases in the closed measuring chamber (8.7) as a result of the permeation, with an enriching time (tA) up to the reaching of the predefinabie upper switchover concentration (cvA) being determined in the first measurement variant; and subsequently using the enriching time (tA) and using The purge time (tS) determined in process step (i) using the first measurement variant and using the course of the permeate concentration (c) determined during the purge time (tS), or the permeation rate (P) of the barrier element (8.5) is calculated using the equationP=∫(c(t)·V.)t·M·pR·T·ttotal·A Where ttotal is the sum of the purge time (tS) and of the enriching time (tA) for the first measurement variant and is the sum of the predefinable purge time (tvS) and of the predefinable enriching time (TvA) for the second measurement variant; M is the molar mass of the permeate; p is the maintained pressure, R is the general gas constant; and T is the temperature maintained during process steps (i) and (ii), using the course of the permeate concentration (c) determined during the predefinable purge time (tvS) using the second measurement variant in process step (i) and using the predefinable purge time (tvS) and the predefinable enriching time (tvA), |
