Abstract: A device detects leaks in a test object (1), which is contained in a test container (2). The device includes a mass spectrometer (14) detecting a noble gas such as helium, and a pump arrangement containing a primary vacuum pump (13) and a spiromolecular pump (11). The noble gas atoms flow through the latter in opposition to the pump direction towards the mass spectrometer. Between the test container (2) and an outlet port (10) of the spiromolecular pump (11), an accumulation chamber (8) is inserted, whose volume is considerably larger than that of the test container (2). The test container is provided with a source of purge gas (3) and a valve (4) for purging the test container with a purge gas under an adjustable overpressure. Closure valve (7) is disposed between the test container (2) and the accumulation chamber (8) and a closure valve (9) between the accumulation chamber (8) and the outlet port (10) of the spiromolecular pump (11).

Abstract: The invention resides in a method for analyzing gases according to the counterflow principle, comprising a mass spectrometer tube (3) located at the suction side of a molecular pump (2). The primary vacuum pressure is adjusted in such a way that basically ambiguous spectrometer indications can only result from a gas with low molecular weight reaching the mass spectrometer in counterflow to the molecular pump and not from a gas with higher molecular weight, which in itself would provoke a similar spectrometer indication.

Abstract: The invention relates to a mechanical vacuum pump having a displacement member (2) and a casing (1) which is provided with an inlet channel (3) on the suction side and an outlet channel (4) on the discharge side. A spring-loaded non-return flap valve (5) is incorporated into the outlet channel (4). Upstream of this flap (5), a gas jet pump (7, 8) is installed in the outlet channel (4), the jet direction being parallel to the sealing surface of the non-return flap valve (5).This gas jet pump allows to significantly increase the final vacuum of the mechanical vacuum pump and to improve the cooling of the pump.

Abstract: A molecular high-vacuum pump has a bell-shaped rotor 5 including a shaft supported by roller bearings 12, 13 disposed inside the bell rotor. The stator 1, 6 defines two converging pumping stages, one in cooperation with the inner cylindrical surface 10 of the rotor and the other in cooperation with the outer cylindrical surface 9 of the rotor. The suction inlet 3 is disposed in the apex area 4 of the bell rotor. The discharge outlet 11 of the pump is disposed in the vicinity of the lower rim of the bell, and both pumping stages transfer gases towards this rim. In this way, gases introduced through the inlet 3 into the pump cannot penetrate into the motor space 15 and damage the bearings of the pump.