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Surface Emissions Testing
In real-world use, some materials will only have one surface exposed to the patient (e.g. breathing bags) and
in this case, this is the only surface that needs to be tested (see figure 3).
Samples may be cut or punched out of the test material and sealed in place at the top of the microchamber
sample pot using sprung spacers so that only VOCs from the surface of interest are collected. Samples of
different thicknesses can be accommodated using appropriately sized spacers.
Fig. 3 – Surface emissions testing: samples are cut out of a material and sealed in place in a microchamber
sample pot to collect VOCs from only the exposed area.
Permeation Testing
Used to measure VOCs permeating through a thin layer of material, the material, e.g. nitrile gloves
or membranes used in filtering systems, is held at the top of a permeation accessory within a
microchamber sample pot and sealed in place, with a gap at the top to collect VOCs (see figure 4).
A liquid sample is introduced, via a septum, into a well at the bottom of the permeation accessory.
The microchamber sample pot is then placed in the µ-CTE and gas is passed over the sample.
VOCs permeating the material through to the top of the sample pot can be collected periodically in
sorbent tubes to determine the length of time it takes for the VOCs to pass through the material.
Fig. 4 – Microchamber permeation accessories enable permeation tests on nitrile gloves, for example.