| 摘要 |
<p>A spectroscopic instrument such as a Fourier transform infrared (FTIR) spectrometer comprises a compartment 2 for housing instrument components 3 and a desiccant 4 to protect the instrument components. A deformable container 5 such as an air bag has at least one wall portion which is movable within the compartment 2 so as to vary the volume of the compartment 2 that is occupied by the deformable container 5 as the container is deformed. The interior of the deformable container 5 is in fluid communication with the surroundings of the instrument via valves (7a, 7b, Fig 7) and a tube-like portion 6 such that a difference in pressure between the compartment and the surroundings tends to cause the deformable container to deform, moving the wall portion. In this way the pressure between the compartment and the surroundings tends to equalise, reducing any pumping effect and thus extending desiccant lifetime.</p> |
