| 摘要 |
A helium leak detector characterized in that it comprises a first molecular pump (T) having a high pumping speed, having its low-pressure outlet connected to an inlet (E) of the detector, and having its high-pressure outlet connected either to a pre-vacuum assembly (10) comprising a first valve (V1) and a first primary pump (P1), or to a measurement assembly (20) for measuring helium pressure and comprising: a first selective filter (F1) constituted by a molecular pump having a low pumping speed and a low compression ratio; and a second selective filter (F2) constituted by a molecular pump having a low pumping speed and a high compression ratio; said first and second filters being connected to one end of a second valve (V2) having its other end connected between the turbomolecular pump and the first valve (V1), said detector further comprising a third selective filter (F3) in parallel with said second valve (V2), said third filter allowing helium to pass therethrough and preventing air or vapor from passing therethrough.
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