Leybold-heraeus Gmbh

Leybold Aktiengesellschaft

Leybold-heraeus Gmbh & Co. Kg

Gunter Reich

Rudolf Flosbach

Werner G Bley

William Worthington

Hans-Joachim Schubert

Leak detecting device working on the counter current principle uses a test piece connected to the inlet of a first turbomolecular pump, a gas detector connected to the inlet of a second turbomolecular pump. First and second molecular pumps downstream of the respective turbomolecular pumps have a common outlet connected to a pre-vacuum pump and reduce the effect of test gas substratum. Both turbomolecular and other molecular pumps are on a common shaft, the passages between each turbomolecular and molecular pumping stage being connected.

Pumping system for a leak detecting device

Leak detector operating according to the countercurrent principle is used in a leak detection method and includes a first high vacuum pump having an inlet which is connected to an inlet of the leak detector, a second high vacuum pump having an inlet which is connected to a mass spectrometer, and a first roughing pump having an inlet which is connected to the outlets of the first and second high vacuum pump respectively. In order, on the one hand, to detect particularly large leaks and, on the other hand, avoid overloads due to high test gas concentrations, a second roughing pump is provided having an inlet which may be selectably connected to one of the inlet of the leak detector via a conduit equipped with a control valve and to the inlet of the first roughing pump by way of a conduit equipped with a choke.

Leak detector and leak detection method

A conduction-responsive meter head has a device having electrical conduction responsive to a condition such as pressure to be metered. The device communicates with the condition to provide its electrical-conduction response to a bridge electrically including the device. A power supply has two terminals on the meter head for providing electrical power to the bridge. The measurement signal from the bridge is provided, however, to a third terminal by a lead from the bridge.

Conduction-responsive meter head

A measuring head for a vacuum gauge. An essentially cylindrical housing encloses a measuring cell which is sealed in a vacuum tight manner against the surrounding atmosphere and is connectable with an evacuatable cavity. A measuring filament for producing an electrical signal corresponding to the pressure in the measuring cell is disposed in the measuring cell. The measuring filament is disposed approximately perpendicularly to the axial direction of the housing.

Measuring head for vacuum gauge

A friction pump (molecular pump, turbomolecular pump) has pumping surfaces which include surface areas which face upstream as well as surface areas which face downstream with respect to the pumping direction. In at least a portion of the pumping surfaces, surface areas of different roughness are present, such that the roughness of the surface areas facing downstream with respect to the pumping direction is greater than the roughness of the surface areas facing upstream with respect to the pumping direction.

Friction pump

A turbomolecular pump for counterflow leakage tests and the method of its use arranges two, tandem turbomolecular pump stages for pumping toward each other and connects opposite ends of the tandem pump stages respectively to a container or test tank through which a test gas is provided when there is a leak and a detector for detecting the test gas. A connection between the tandem pump stages connects to a forepump for assisting the turbomolecular pump. Arranging the turbomolecular pump in this way permits different pressures in the container or test tank and detector, as is often desired when, for example, the detector is a mass spectrometer, without partition and conduit arrangements therefor.

Turbomolecular pump suitable for performing counterflow leakage tests

A method of operating a gas examining apparatus which has a gas examining device such as a mass spectrometer, a chamber communicating with the gas examining device, a gas pump communicating with the chamber and a probe hose coupled to the chamber for introducing into the apparatus gas to be examined. According to the method, in case probe hoses of different lengths or different quantities are used, the gas examination is so performed that the pressure in the above-mentioned chamber arranged upstream of the gas examining apparatus is maintained constant.

Method and arrangement for operating gas examining apparatuses

In order to evacuate a receptacle using a pumping arrangement composed of a backing pump connected to the receptacle and a fine or high vacuum pump connected to the receptacle via a cold trap, the receptacle is initially evacuated only by operation of the backing pump, the time taken to achieve a predetermined initial pressure reduction in the receptacle only by the action of the backing pump is measured, then, on the basis of the magnitude of such pressure reduction and the measured time period, the subsequent time period which would be required, if the effect of condensable gases in the receptacle were ignored, to reach a predetermined second pressure, lower than the first pressure, in the operating range of the fine or high vacuum pump is calculated, and the receptacle is then evacuated by operation of the fine or high vacuum pump at the expiration of the subsequent time period.

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Cologne, Germany

Gunter Reich