| 摘要 |
A gas chromatograph/mass spectrometer combination (11, 12) has an insulated compartment (15) for the temperature control of a capillary column (16) containing a gaseous sample which progresses via the inlet (17), column (16) and outlet conduit (14) to the mass spectrometer unit (12) for completion of the analysis. A housing (13) surrounds the compartment (15) and its upper surface (22) sub-divides the clearance between the units (11, 12) into two spaces (23, 24) to form a thermal barrier. The temperature stability of the combination is materially enhanced by an upper fan (28, 29) which draws air through the space (24) to cool the baseplate (26) and turbo-molecular vacuum pump (27) whilst a lower fan assembly (19, 20, 21) circulates air through the space (23) and assists temperature uniformity in the compartment (15).
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