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ERDC/CRREL TR-02-12
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RESULTS AND DISCUSSION
Ease of use
The easiest sampler to use was the PDB sampler since all that is required is
to place it in the well and then remove it after two, or more, weeks' equilibration.
We used a glass Pasteur pipet to puncture the device and transfer the sample to a
sample bottle. However, we found it difficult to control the flow into the bottle
because the bag was flexible and tended to flop over. We found that it was easier
to transfer the sample to a vial if the sampler was placed on a stand that held it
upright. This allowed the individual taking the sample to have both hands free to
collect the sample.
The HydraSleeve was lightweight and also relatively easy to operate.
However, pouring the sample out of this device was also tricky for the same
reasons and because the check valve had to be held open. We found it took two
people to fill the sample vial; one person used a glass Pasteur pipet to hold the
check valve open while the other held up the far end of the bag to help control
the flow from the bag. Again, it might be better to transfer the sample to a vial by
using a stand to hold the HydraSleeve upright and then puncture it as we did with
the bag sampler. The manufacturer currently recommends obtaining a sample in
this manner.
The Kabis Sampler was also easy to operate. The trickiest aspects of using
this device were lowering it at a slow and steady rate and allowing enough time
for it to fill. One advantage with this sampler was that once the sample was
collected in the well, it did not have to be transferred to another container. How-
ever, because we tested one of the larger diameter devices, it was relatively heavy
when it was full.
Operating the Discrete Interval Sampler was more complicated and took
longer than the three previous samplers because it had to be pressurized prior to
sampling and prior to retrieving the sample. However, it was much lighter in
weight than its counterpart, the PneumoBailer. We also found that this device
was easier to bring into the field than the PneumoBailer because all that was
needed to pressurize this device was a hand pump, vs. bringing a gas cylinder
into the field. We were able to control the flow of the sample into the sample
bottle extremely well with both of these devices.
The manufacturer gives 28 steps for collecting a sample with the Pneumo
Bailer, and we found that this was the most difficult device to operate. There are
several steps where you hook the tubing to the cylinder, then unhook it and re-
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