Abstract: A sniffing leak detector comprises a handle with a sniffing tip. Located at the sniffing tip is a measurement gas suction opening and a reference gas suction opening. The reference gas suction opening is intended for suctioning ambient gas. The reference gas suction opening is aligned substantially the same as the measurement gas suction opening such that both suction openings are sensitive in the same direction.

Abstract: The invention relates to a leak detector comprising a first sensor for detecting a gas component (helium) in a gas taken in. Because the sensor is susceptible to saturation or contamination, a second sensor is provided. The sensor is a thermal conductivity sensor. The thermal conductivity sensor has a lower detection sensitivity, yet, at a high concentration of the gas component, it does not risk being contaminated. The two sensors together allow for a large detection range, from extremely sensitive measurements to instances with high concentrations of the gas components as those which can occur with gross leaks.

Abstract: The leak detection appliance has a test inlet to which a test chamber containing the test specimen can be connected. A high-vacuum pump produces a high vacuum in a test gas detector. A preliminary vacuum pump contains two pump stages. In order to evacuate the test chamber, the pump stages are operated in parallel mode, with their suction capabilities being added. When the necessary vacuum has been achieved, the pump stages are operated in series in order to produce the necessary high vacuum—which is required for high detection sensitivity—on the test gas detector.

Abstract: In order to test water-bearing components for leak tightness, a coating (19) is provided, which comprises a mixture made of a water-soluble base substance and a generator substance. Upon contact with water, the coating (19) releases an indicator gas. The indicator gas is detected by a sensor (13).

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: Calibrating a measuring cell arrangement having a diaphragm vacuum measuring cell having a programmable heater for heating the diaphragm vacuum measuring cell to a constant presettable temperature. The heater encompasses the measuring cells and is encompassed by an insulation jacket. The method includes setting a first heating temperature on the measuring cell to a constant preset value, performing a first calibration step by generating at least one preset pressure in a vacuum volume and obtaining vacuum measuring signals of the measuring cell and at least one reference measuring cell, storing pressure values in the memory, determining compensation values from the difference values of the measuring cell and the reference measuring cell, intermediately storing these difference values in a calibration data memory and gauging the measuring cell by transmitting the determined compensation values to the measuring cell data memory.

Abstract: An illumination device is provided at the handle-piece of a sniffing probe, in which the illumination device illuminates the region to be inspected. This incorporation considerably facilitates handling of the sniffing probe in difficult-to-access and poorly illuminated regions, for sniffing probes used for detecting gases, for example, for detecting a gas leakage in a cooling device of a motor vehicle.

Abstract: A cathode configuration for emission of electrons has a reaction zone connected to an entrance opening for the supply of neutral particles. The opening communicates with the cathode configuration for the ionization of the neutral particles and an ion extraction system communicates with the reaction zone. Ions from the extraction system are sent to a detection system and a mechanism for the evacuation of the mass spectrometer arrangement. The cathode configuration includes a field emission cathode with an emitter surface, wherein at a short distance from this emitter surface, an extraction grid is disposed for the extraction of electrons, which grid substantially covers the emitter surface. The emitter surface encompasses herein at least partially a hollow volume such that a tubular structure is formed.

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: Usually, a sniffing leak detector must be calibrated for each tracing gas. The calibration comprises ranging of the spectral positions into the mass spectrum and the amplitude height. At least one mass line is determined with a calibrating gas. The mass lines lying between two mass lines and/or between a zero point and a line are determined by interpolation and/or extrapolation. In this manner, a sniffing leak detector can be used for such tracing gases which have not previously been used for calibration purposes.

Abstract: For leak testing, a tracer gas is advanced to the outer wall (11) of the hollow test object (10) while the test object (10) is in an evacuated state. The tracer gas is discharged from a blower device (14) in the form of soap bubbles (21). When contacting the outer wall (11), the soap bubbles will burst, thus forming a cloud (27) of tracer gas immediately on the outer wall (11). By the invention, it is made easier to localize the invisible tracer gas in the ambient air. Further, the tracer gas can be used more effectively so that the costs for performing the testing process are reduced.

Abstract: The leak detector comprises a basic unit that is connected to a probe by a hose. The probe tip is placed against test zones of the test object. In case that test gas escapes from the test object, this is detected by a test gas detector in the base unit. According to the disclosure, a position determining system is provided which comprises a transmitter, a receiver that is disposed inside the probe, and a supply and evaluation unit. Thereby, the presence of the probe tip in the individual test zones is monitored and confirmed.

Abstract: In order to determine leakage on a device, which contains gas that can be condensed, an adsorbent is used through which ambient gas of the object is conducted. The adsorbed gas is desorbed by means of actuating an excitation device and fed to a gas sensor containing a mass spectrometer. In this way, minute amounts of leaking gas can be determined by means of accumulation. The method is in particular suited for use in the serial production of refrigeration machines.

Abstract: The invention relates to a sniffing leak detector comprising a sniffing line (11) and a feed line (33) that leads to a vacuum pump (16). A distribution point (24) from which a branch line (25) leads to a test gas sensor (15) is provided on the feed line (33). In order for the intermediate pressure (P2) at the distribution point (24) to be independent of feed fluctuations of the vacuum pump (16), a throttle (D2) comprising a supercritically operated orifice (20) is provided between the distribution point (24) and the vacuum pump (16). The pressure drop at the orifice (20) is greater than half the intermediate pressure (P2) at the distribution point (24). The flow at the orifice (20) is thus blocked, wherein the flow (Q) remains constant regardless of changes of the pump pressure (P3). Changes of the intermediate pressure (P2) are thus prevented so that the sensitivity and signal stability of the test gas sensor (15) is unaffected by changes of the pump pressure.

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: 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: For refrigeration units, maintenance machines are required that can receive and compress the refrigerant from the refrigeration unit. Furthermore, a vacuum pump is required, which is connected to the emptied lines and pumps out humidity and air. The maintenance machine according to the invention includes a motor that drives a compressor via a freewheel in one rotational direction. The same motor drives a vacuum pump via a second freewheel in the other rotational direction. The maintenance machine, which can perform two different functions, includes only one single motor. The machine is lightweight, so that it can be carried by the maintenance personnel. Furthermore, it is small and can be produced in a cost-effective manner.

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 valve arrangement has an annular housing with valve seat and a two-part valve plate that is rotatable about an axis. The seat is in the form of a disk including two adjacent openings with a web between and the axis is parallel to the web. The two parts of the valve plate are next to each other with their planes parallel and offset in a perpendicular direction. They are connected to each other through one of the openings by a connection piece extending through the one opening. In a closed position for the valve, the valve plate part are respectively positioned on opposite sides of the valve seat and cover and seal the respective openings due to a seal that is between the valve plate parts and the valve seat.

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.