| 摘要 |
An apparatus for testing the emissions, content or permeability of samples of materials, comprises at least two sample chambers (5a,5b), each in communication with a receiver (9a,9b) for a sorbent trap (10a,10b), a gas inlet conduit (2) having at least two gas delivery conduits (3a,3b), arranged to deliver gas to respective sample chambers, and at least two gas-flow impedance devices (4a,4b), arranged to control the flow of gas through respective sample chambers and through respective sorbent traps. The gas-flow impedance devices preferably comprise a body of porous material and serve to ensure that the rate of flow of gas is substantially the same through each and every sample chamber, regardless of whether a given sample chamber is in use, with a sorbent trap in place or not, or if different sorbent traps are in use for the different sample chambers. |
