InstroTek
19
8.
Place the channel bag with the rough side down inside the external bag. It is
important that the channel side (rough side) of the bag is face down against
the bottom. This will help in removing the air from underneath the sample.
9.
Place your hand inside the channel bag and gently and evenly spread the
sample within the channel bag.
Do not try to spread the sample by
squeezing down on the bags. Putting pressure on the bags will create
punctures.
10.
Push in the opening of the channel bag away from the opening of the
external bag.
Make certain that the channel bag opening is not folded as to
restrict airflow out of the bag and the channel bag is about 1” (25mm) away
from the closed end of the external bag.
11.
Place the external bag opening over the seal bar and close the chamber
door. The channel bag should not be over the seal bar.
After the vacuum and sealing operation the chamber door will open. See
“SEAL”
on
page 11
for additional information. Gently remove the sealed sample
from the chamber and immediately transfer the sample to a large water bath
equipped with scales. Completely submerge the bag in water and while
submerged (at least 2” under water) cut the bag under the seal joint but above
the channel bag. The bag opening should extend all the way across, leaving
approximately 1” intact.
Note: Cutting the bag too close to the water surface will allow air to enter the
bag and would negatively impact the result. Always keep the sample a
minimum of 2” under water.
12.
Open both bags while under water and hold open for 15 seconds to allow
the water to enter the two bags and wet the sample.
Note: If you notice a massive amount (like boiling water) of bubbles coming out
of the bags, then the test should be repeated. The bag has been punctured.
13.
Carefully fold the bags over and, while keeping them completely under
water, place the sample on the provided weighing basket hung from the
scale.
14.
While over the weighing basket open the bags and let water freely enter the
bags.
15.
If necessary, use the alligator clip tied to the weighing basket to stop the
bags from floating above the surface of the water.
Caution: Make certain the bag is not touching the sides or the bottom of the
water tank.
16.
Allow the scales to stabilize and record the weight in column C.
