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AQUATRAN Model 3/40 Operator's Manual
Chapter 3: Preparing for a Test
This chapter provides information on how to prepare for a permeation test.
Read this chapter to learn about:
Testing Basics
•
•
How Barrier Properties Affect Testing
Developing Test Methods for Films and Packages
•
•
Humidified Environment Testing
Testing Basics
A permeation test is comprised of a series of discrete actions or events. Some of these steps require human
thought, action or intervention. Some of the steps are performed by the instrument and will be discussed
elsewhere. The most important part of the process is the planning and preparation that occurs before the
actual testing begins. Inadequate planning or preparation may result in an inaccurate measurement. This
chapter contains information on the factors that should be considered when planning for a permeation test.
How Barrier Properties Affect Testing
A good understanding of the barrier material properties for the samples to be tested is very helpful when
preparing for a permeation test. The transmission rate of the sample and the conditions at which it will be
tested may require changes to the test methodology.
Any sample with a transmission rate within the range of the instrument (as specified in Chapter 10) can be
tested. Additional consideration is advised when setting up tests for samples that are Very Good or Very
Poor barriers. A Very Good Barrier is generally considered any material with a transmission rate less than
0.1 g / (m
• day) or 0.0005 g / (pkg • day). A Very Poor Barrier is generally considered any material with a
2
transmission rate greater than 100 g / (m
gas.
Testing Very Good Barriers
When testing a Very Good Barrier, use a sample with the largest possible surface area. It may be
necessary to combine multiple samples, using a common fixture, when testing Very Good Barrier packages
with small individual surface areas. Longer Cell Examination and ReZero Examination times may be
required. An Individual Zero test phase is recommended when testing Very Good Barriers.
Testing Very Poor Barriers
Use caution when testing Very Poor Barriers an excessively high transmission rate will over-range the water
vapor sensor. Persistent or repeated over-range conditions can damage the water vapor sensor. There are
two ways to reduce the possibility of an over-range when testing poor barriers:
Reduce the water vapor concentration (RH) of the Test Gas, but with caution.
•
When testing film samples use a mask to reduce the sample area.
•
MOCON, Inc.
2
• day) or 0.5 g / (pkg • day) when using a 100% RH as the test
Revision D
Preparing for a Test
3-1
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