Abstract: The invention relates to a cold cathode pressure sensor comprising a gastight housing having a test gas inlet, an anode and a cathode arranged in said housing, and a radiation source directed to said cathode for igniting a cold cathode discharge. Said housing is at least partly made of glass. Said radiation source is arranged outside said housing and irradiates said cathode through the housing glass. Said radiation source substantially emits a radiation of a wavelength of more than 350 nm and less than 1,400 nm.

Abstract: An electron-emitting cathode consists of an electrically conducting emitter layer attached to a side wall which consists of stainless steel and a gate which is fixed at a mall distance inside a concave emitter surface of the emitter layer. The cathode surrounds a reaction area containing a cylindrical grid-like anode and a central ion collector which consists of a straight axial filament. An ion collector current reflecting the density of the gas in the reaction region is measured by a current meter while a gate voltage is kept between the ground voltage of the emitter layer and a higher anode voltage and is regulated in such a way that an anode current is kept constant. The emitter layer may consists of carbon nanotubes, diamond-like carbon, a metal or a mixture of metals or a semiconductor material, e.g., silicon which may be coated, e.g., with carbide or molybdenum. The emitter surface can, however, also be a portion of the inside surface of the side wall roughened by, e.g., chemical etching.

Abstract: A leak rate measuring device contains a strip spectrometer in which the ion path of the respective gas is influenced by at least one variable influencing quantity. When a gas having a predetermined mass is detected, and leakages of a gas having other predetermined masses interfere with this detection due to lack of selectivity of the spectrometer, the influencing quantity is modulated in a sinusoidal manner, and the wanted signal is subsequently selected in a lock-in amplifier. This modulation enables, for example, the elimination of the interfering influence of underground water during the leak rate measurement while using helium as a test gas.

Abstract: In a leak detector with a sniffer probe, the invention provides that the sniffer tube (12), which is provided in the form of a throttling capillary line and which leads from the sniffer probe (10) to a vacuum chamber (13), has an inner cross-sectional area that varies in the longitudinal direction. The cross-sectional area enlarges in the direction of flow of the drawn-in gas, thus from the inlet (11) to the vacuum chamber. This reduces the dead time, i.e. the transit time of the gas through the sniffer tube (12).

Abstract: The invention relates to a leak detector including a hand-held device with a sniffer tip. A distance detector for detecting a defined distance of the sniffer tip from the test object is provided on the sniffer tip. A test is only initiated if the distance between the sniffer tip and the test object is correct, thereby avoiding measuring errors due to wrong manual positioning of the sniffer probe. The leak detector can also be provided with an acceleration detector, which permits the test to be carried out only if the sniffer probe is kept steady.

Abstract: A vacuum measuring cell has a first housing body and a membrane, both of Al2O3 ceramic or sapphire. The membrane is planar with a peripheral edge joined by a first seal to the first housing body to form a reference vacuum chamber. A second housing body of Al2O3 ceramic or sapphire opposite the membrane, is joined to the peripheral edge of the membrane by a second seal to form a measurement vacuum chamber. A port connects the vacuum measuring cell to a medium to be measured. At least in the central area of the first housing body, an optical transparent window is formed and at least the central region of the membrane has an optically reflective surface. Outside the reference vacuum chamber, in opposition to and at a distance from the window, an optical fibre is arranged for feeding in and out light onto the surface of the membrane.

Abstract: For operating a hydrogen test leak unit comprising a chamber (21) defined by a membrane (22), a test gas mixture of hydrogen and an added gas is used. The added gas has a permeation coefficient relative to the material of the membrane (22) ranging between 50% and 200% of that of hydrogen. In this manner, demixing of the test gas mixture is limited and significant concentration variations in the chamber (21) are prevented. Preferably, helium is used as added gas.

Abstract: The invention relates to a sensor (1) for helium or hydrogen with a vacuum-tight housing (2), wherein a gas consuming cold cathode array (3, 4) is arranged, in addition to a selectively active passage (9) for the gas to be detected. According to the invention, in order to improve the properties of said sensor, the housing (2) is made of glass, components of the gas passage (9) include a membrane (18) made of a silicon material having the desired selective qualities, in addition to a silicon plate (19) which supports the membrane (18) and is provided with a plurality of openings (21) and a heating element (24). The housing (2) and the selectively active gas passage (9) are joined together without polymer and elastomer.

Abstract: A leak detecting device of the counterflow type includes a high vacuum pump having an inlet connected to a mass spectrometer. In addition, a prevacuum pump is provided having an inlet connected to an outlet of the high vacuum pump and a leak detecting device input. A connecting conduit is further provided between the leak detecting device input and an intermediate inlet of the high vacuum pump. A first valve of variable conductance is arranged in the course of the connecting conduit. Valves with a large inner diameter are expensive while valves with a small inner diameter show considerable resistance even in a fully opened state. A second valve arranged parallel to the first adjustable valve is provided in the course of the connecting conduit; thereby allowing the first and second valves to have relatively small inner diameters arranged in the connecting conduit, wherein the combined conductance of both opened valves is considerably increased.

Abstract: A leak test apparatus includes a housing having an interior sized for retaining a plurality of instrument components including a control unit. A sniffer gun is linked to the instrument components, the sniffer gun having an intake point, and a test leak includes a gas reservoir, a constriction, an opening suited for introducing the intake point of said sniffer gun, and a temperature sensor. The temperature sensor is linked, either by means of a wired connection or wirelessly to the control unit for signal transfer.

Abstract: A reference leakage device for a leak sniffer detector that is equipped with a sniffing tip and a control unit. The reference leakage device includes a gas reservoir and a constriction wherefrom there is released a specific amount of test gas, at least during calibration. A sensor is located in the constriction for detecting the approach of the sniffing tip wherein the device further is capable of transmitting signals to control unit of the leak detector.

Abstract: A sniffing leak detector includes a handpiece, supporting a sniffing tip, the detector further including a gas sensor. To promote longer life and obtaining more accurate results, the leak detector is equipped with an acceleration sensor for recording the movements of the handpiece.

Abstract: A leak detecting device of the counterflow type includes a high vacuum pump having an inlet connected to a mass spectrometer. In addition, a prevacuum pump is provided having an inlet connected to an outlet of the high vacuum pump and a leak detecting device input. A connecting conduit is further provided between the leak detecting device input and an intermediate inlet of the high vacuum pump. A first valve of variable conductance is arranged in the course of the connecting conduit. Valves with a large inner diameter are expensive while valves with a small inner diameter show considerable resistance even in a fully opened state. A second valve arranged parallel to the first adjustable valve is provided in the course of the connecting conduit; thereby allowing the first and second valves to have relatively small inner diameters arranged in the connecting conduit, wherein the combined conductance of both opened valves is considerably increased.

Abstract: The invention relates to a method and a device for detecting leaks in the wall of a test object, container or similar, by measuring and evaluating changes that occur in a partial gas pressure. The invention aims to simplify the detection of leaks. To this end, changes that occur in partial pressures of oxygen are detected and evaluated using an oxygen sensor (4).

Abstract: A leak detector operating according to the counterflow principle comprises a first high vacuum pump that operates in series with a primary pump. A second high vacuum pump is branched at a connecting point and an entry side thereof is connected to a mass spectrometer. A light test gas in the form of helium flows through the second high vacuum pump in a direction opposite to a transport direction. A conduit connecting an inlet to the entry side of the first high vacuum pump is devoid of restricted flow zones and valves in such a way that the pumping capacity of the leak detector is high for helium, thereby reducing the response time thereof. A valve for blocking the conduit leading via the first high vacuum pump is arranged between the exit side thereof and the entry side of the primary pump.

Abstract: A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.

Abstract: A leak indicator including a housing that houses components of the indicator as well as a test leak, and test leaks that are suitable for integration into a leak indicator.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 ?m, in particular less than 120 ?m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: An electron-emitting cathode consists of an electrically conducting emitter layer attached to a side wall which consists of stainless steel and a gate which is fixed at a mall distance inside a concave emitter surface of the emitter layer. The cathode surrounds a reaction area containing a cylindrical grid-like anode and a central ion collector which consists of a straight axial filament. An ion collector current reflecting the density of the gas in the reaction region is measured by a current meter while a gate voltage is kept between the ground voltage of the emitter layer and a higher anode voltage and is regulated in such a way that an anode current is kept constant. The emitter layer may consists of carbon nanotubes, diamond-like carbon, a metal or a mixture of metals or a semiconductor material, e.g., silicon which may be coated, e.g., with carbide or molybdenum. The emitter surface can, however, also be a portion of the inside surface of the side wall roughened by, e.g., chemical etching.

Abstract: A test gas leakage detector includes an inlet for gases to be analyzed for the presence of a test gas, a test gas detector and a first high vacuum pump connected to the test gas detector. An intermediate inlet is arranged on the first high vacuum pump that is used to supply the gases to be analyzed for the presence of a test gas. A fore-vacuum pump is connected to the first high vacuum pump and a line section fitted with a valve is located between the inlet and the fore-vacuum pump. In order to provide greater sensitivity and a quicker result time, a second high vacuum pump is provided between the inlet and the intermediate inlet. The second high vacuum pump has an outlet which is connected to the inlet of the fore-vacuum pump by means of a line section fitted with a valve.