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Introduction
AQUATRAN Model 3/40 Operator's Manual
Permeation Test Overview
A "Permeation Test" consists of up to two phases that are performed using a Test Cell. The "Cell" may
contain a package cartridge or a film cartridge. The Test Phase (always present) is used to measure the
transmission rate of the test sample. The Individual Zero Phase is optional and may occur at the beginning
or end of a Permeation Test. Each phase in the test consists of a series of discrete states. A Permeation
Test may utilize all or only a subset of the possible test states. During a test the steps (or states) within each
phase are executed in a fixed order. This order is called the "Test Sequence". A brief description of the
phases and states within a permeation test are given below:
Individual Zero Phase
An Individual Zero Phase is used to determine the amount of water vapor that is present in the carrier gas
from factors other than actual transmission through the sample. The Individual Zero value is used to correct
the transmission rate values obtained from each sample during testing. For more information on when and
how to use an Individual Zero Phase see "Individual Zero Processing" in Chapter 3.
Conditioning the Sample
Almost every material requires a period of time to acclimate to the test environment and reach equilibrium.
A conditioning state can be specified to allow the barrier to "Condition" to the test environment. When used,
the Conditioning State will occur at the beginning of each test phase. See details in Chapter 3.
ReZero State
Periodically the instrument baseline must be measured so that any changes in the baseline will not affect
the accuracy of your transmission rate data. This is done during a "ReZero State" by measuring the
apparent Water Vapor Transmission Rate of the ReZero Cell.
Cell Examination State
The Cell Examination State is used to measure the transmission rate of the barrier sample. The carrier gas
leaving the Test Cell is sent to the water vapor sensor where the amount of water vapor contained in the
gas is measured to determine a transmission rate.
Bypass State
When no gas is being routed to the water vapor sensor it is said to be in the Bypass State. The Bypass
State is used to maximize the useful life of the sensor. The water vapor sensor is automatically placed in
Bypass during conditioning, when tests are completed or when an excessively high level of water vapor is
detected.
Test Completion
At some point sufficient measurements will have been made to accurately determine the transmission rate
of the samples. A Permeation Test can be terminated manually by the user, after a fixed number of test
cycles or using an automatic convergence process. When testing is complete, the cell is removed from the
test sequence and no further transmission rate examination of that sample is performed. For more
information on stopping a transmission rate test see "Determining When to Stop a Test" in Chapter 3.
Report Generation
You can request a report for one or all cells at any time until a new permeation test is started. See the
instrument Help System for information on printing reports.
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Revision D
MOCON, Inc.
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