Abstract: A hydrogen sensor includes a housing, which is closed off by a membrane that is made of palladium and selectively only pervious to hydrogen. The housing is evacuated and contains a Pirani pressure sensor. The membrane and the Pirani pressure sensor are each attached to a carrier. Both carriers are joined directly next to one another or kept at a distance by a connection piece. The hydrogen sensor has a high sensitivity and a low response time due to the relatively large membrane surface and the low housing volume. It can be produced in a small size and integrated in the handle of a sniffer-type leak indicator.

Abstract: A leak detector comprising a base appliance provided with a gas detector, a vacuum pump, and a control device. A sniffer probe is connected to the base appliance. A test leak device containing the supply of test gas is arranged in a separate sub-housing. The sub-housing also contains a temperature sensor, a processor, and a data memory. The processor corrects the measured temperature according to a sample, and modulates the light of a light barrier. The processor is connected to the control device in the base appliance by a data cable.

Abstract: A membrane selectively permeable to light gases comprises a membrane body formed by a first plate and a second plate. The second plate comprises a thin layer that is selectively gas-permeable. In the region of windows, this layer is exposed. There, support is provided by a porous bottom wall in the first plate or by narrow bores in the second plate. A heating device causes a radiation heating of the windows.

Abstract: A leak detector comprises a cell provided with a tracer gas inlet preferably permeable to a tracer gas. In the cell, the tracer gas is caused to assume an energetically higher metastable state. By means of laser spectroscopy the absorption spectrum of the metastable tracer gas is sampled in an optical measuring section, whereby the presence of tracer gas is detected.

Abstract: A sniffer leak detector comprising a detector with a quartz window, the window being selectively permeable to a tracer gas. The quartz window is located in a suction chamber that is connected to a vacuum pump. To reduce the response time, a gas guidance plate is situated in the suction chamber, the guidance plate and quartz window together delimiting a narrow gas guidance chamber.

Abstract: The gas sensor has a selectively permeable membrane which is composed of silicon material and is provided with a heating device on the outside. The membrane closes an evacuated housing which contains a pressure sensor. When evacuating the area surrounding the housing, the heat dissipation is changed as a result of the quick change in the total pressure of the surrounding air, with the result that signal drift arises despite temperature regulation of the membrane. The disclosure provides at least one second heating device whose temperature is regulated independently of the first heating device. As a result, the membrane temperature is highly constant even in the case of severely changing total pressure in the housing.

Abstract: A leak detector having a pre-vacuum feed pump, a gas detector and a flow sensor. The detector also includes a buffer volume and a restrictor to be arranged between the feed pump and the flow sensor. This protects the flow sensor against pressure surges generated by the feed pump.

Abstract: The helium sensor comprises a housing that encloses a detection chamber. A side of the housing is closed by a permeable wall that is selective for helium. In the detection chamber, there is located an ion getter pump comprising an anode, a cathode and a magnetic field. The cathode, or a cathode leg is made of beryllium. Beryllium has a low atomic mass, whereby the likewise light-weight helium ions can be better incorporated into the cathode material.

Abstract: A test subject, which is filled with test gas, is placed in a testing chamber, which can be evacuated. A carrier gas is conducted into the testing chamber, so that a gas mixture made of carrier gas and test gas forms therein. The gas mixture is suctioned out of the testing chamber by a compressor pump. A testing gas sensor is connected to the outlet of the compressor pump. The test gas is contained in the compressed gas mixture at a partial pressure which is increased by the compression ratio. In this manner, the sensitivity of the test gas recognition is increased and/or the time constant of the measurement is shortened.

Abstract: A sniffing leak detector which comprises a first suction line in a sniffing probe, the line leading to a main device, is provided with a larger second suction line through which gas is sucked in from the sniffing tip by a gas delivery pump. By connecting the second suction line, the distance sensitivity is increased. By disconnecting the second suction line, on the other hand, the sensitivity is increased. Thus, it is possible to first search for leaks by use of a high gas throughput and subsequently exactly determine the leaks under the quantitative aspect by use of a reduced flow.

Abstract: A cold cathode pressure sensor has gastight housing, an anode and a cathode arranged in the housing, and a radiation source directed to the cathode for igniting a cold cathode discharge. The housing has a test gas inlet and is at least partly made of glass. The radiation source is arranged outside the housing and irradiates the cathode through the housing glass. The radiation source substantially emits a radiation of a wavelength of more than 400 nm and less than 1,400 nm.

Abstract: The leak detector includes a basic device which includes a vacuum pump, a test gas sensor, and a hand-held sniffing probe. The sniffing probe is connected with the basic device via a flexible hose line which includes capillary tubes. At least two capillary tubes are provided, which are adapted to be opened via valves. Thus different capillary cross sections can be rendered operative. The dead time between the entry of the test gas into the sniffing probe and the detection by the test gas sensor can be changed and/or selected. Thus, even the smallest detectable leak rate can be changed and/or selected. The leak detector can be adapted to different requirements by the user without the need for exchanging the hose line. Further, it is possible to equip different leak detectors of the same device family with the same hose lines.

Abstract: To achieve a large measurement range from small up to larger leakage rates, a switchover from normal operation to gross operation occurs. In gross operation, the sucked-in gas flow is separated by different throttles, wherein the throttle that leads to the test gas sensor has a low flow rate. This manner of operation prevents a too large quantity of test gas from reaching the sensor surface and contaminating the sensor. In another alternative, in gross operation the test gas flows only across a part of the sensor surface. The other part is flushed.

Abstract: A sniffing leak detector which comprises a mass spectrometer, a turbomolecular pump and a forevacuum pump. In case that the sniffing hose with the hand-operated sniffing probe becomes detached from the main device, atmospheric pressure would pass into the gas inlet conduit and disrupt the high vacuum in the mass spectrometer. In order to protect the mass spectrometer and the vacuum pump apparatus, a flow restrictor with an upstream filter is arranged in the gas inlet conduit.

Abstract: A leak detector comprising a base appliance provided with a gas detector, a vacuum pump, and a control device. A sniffer probe is connected to the base appliance. A test leak device containing the supply of test gas is arranged in a separate sub-housing. The sub-housing also contains a temperature sensor, a processor, and a data memory. The processor corrects the measured temperature according to a sample, and modulates the light of a light barrier. The processor is connected to the control device in the base appliance by a data cable.

Abstract: The gas sensor has a selectively permeable membrane which is composed of silicon material and is provided with a heating device on the outside. The membrane closes an evacuated housing which contains a pressure sensor. When evacuating the area surrounding the housing, the heat dissipation is changed as a result of the quick change in the total pressure of the surrounding air, with the result that signal drift arises despite temperature regulation of the membrane. The disclosure provides at least one second heating device whose temperature is regulated independently of the first heating device. As a result, the membrane temperature is highly constant even in the case of severely changing total pressure in the housing.

Abstract: A leak testing device includes a chamber which is hermetically sealed towards the environment, having a test object filled with a test gas that is positioned in the chamber. In the chamber, a partial-pressure sensor is arranged that selectively responds to the test gas, but not to the filler gas. Thus, a leak test can be simply performed without high vacuum and without mass spectrometers.

Abstract: The leak detector comprises a basic device (10) which includes a vacuum pump (11) and a test gas sensor (12), and a hand-held sniffing probe (16). The sniffing probe (16) is connected with the basic device (10) via a flexible hose line (15) which includes capillary tubes (20). According to the invention, at least two capillary tubes (20) are provided which are adapted to be opened via valves (23). Thus different capillary cross sections can be rendered operative. The dead time between the entry of the test gas into the sniffing probe (16) and the detection by the test gas sensor (12) can be changed and/or selected. Thus even the smallest detectable leak rate can be changed and/or selected. The leak detector can be adapted to different requirements by the user without the need for exchanging the hose line. Further, it is possible to equip different leak detectors of the same device family with the same hose lines.

Abstract: A gas transmitter having selective gas permeable surfaces includes a support disc that is provided with a plurality of through openings. The support disc is made from a semiconductor material. The transmitter further includes a membrane covering the openings in the support disc thereby forming the selective gas permeable surfaces and further controls the temperature of the membrane.

Abstract: The invention relates to a gas sensor comprising a pump chamber (11) which is connected to a getter pump (30) by means of a throttle channel (20). The detection chamber (11) is closed by a wall (12, 13) that is selectively permeable only to hydrogen. The getter pump (30) sucks hydrogen out of the detection chamber (11). Hydrogen is detected by a highly sensitive pressure sensor (14) when it is diffused into the pump chamber (11) through the wall (12, 13). Said gas sensor has a simple structure and does not require a mass spectrometer.