Testing Film Samples
AQUATRAN 3/38 Operator’s Manual
6-2
Revision G
MOCON, Inc.
Preparing for a Film Test
Before a test can be conducted there are a number of tasks that must be performed: The samples to be
tested must be prepared. The samples must be mounted in a Test Cartridge and Loaded into the
instrument. Finally, if the test requires a Generated RH the Humidifier must be checked and filled if
necessary.
For information on preparing the film samples refer to the sections on “Sample Size”, “” and “Loading and
Unloading the Test Cartridge” in this chapter.
For information on mounting samples and loading the test cartridge refer to “Mounting Samples” and
“Loading and Unloading the Test Cartridge” in this chapter
For information on fill the Humidifiers refer to “Filling the Humidifier” in this chapter
Sample Size
The film sample should be approximately 4" x 4" (10.16 x 10.16 cm), with a thickness not exceeding 2 mm
(0.08 inches). Smaller samples can be masked to allow them to be mounted, see the following section on “”.
The film must be cut to a specific size and shape so it will fit in the Test Cartridge. MOCON provides a film
template (available as part of optional Starter Kit 054-161) as an aid to cutting your film samples.
Special Cartridge for Thick Samples
For samples with thickness up to 1/8”, a specially designed cartridge with two side-by side 10cm
2
cells, or
with two side-by-side 5cm
2
cells can be used. Refer to a separate User Guide 054-641 for details.
Using Masks
A foil mask should be used if any of these conditions exist:
•
You are testing a material with a transmission rate near or exceeding 100 g / (m
2
• day) (such
as nylon or polycarbonate). If such materials are tested as full size samples, the sensor may
over range.
Using a 5 cm
2
mask will reduce the amount of water vapor sent to the sensor by a factor of
10 allowing a sample with an un-masked (50 cm
2
area) transmission rate of 1000 g / (m
2
•
day) to be tested safely.
•
The test material is not available in pieces large enough to mount in the cell.
•
The test material is too fragile to support itself across the full cell area.
NOTE:
Some materials may fail to adhere fully to the masks, and thus give erroneous and/or highly
variable sample-to-sample transmission rates. Always check the compatibility and seal of
your sample to the mask adhesive to determine if these problems exist.
When using a mask, specify the mask open area before starting the test. The mask reduces the area of the
test sample (from the standard unmasked 50 cm
2
area). To correctly calculate transmission rate, the
instrument must compensate for the difference between the masked and unmasked areas.
