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: 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: 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 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: In the leak detection method, it is provided that a specimen (24) filled with a test gas is positioned in front of a suction opening (11). The suctioned air brushes along the surface of said specimen and takes up test gas in the case of a leak. Said test gas is recognized by a test gas detector (17,17a). According to the invention, full mobility of said specimen (24) is ensured during the testing process such that a test can also be carried out while said specimens are moving past said suction opening.

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: 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: 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: 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: 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 sampling leak detector which comprises a basic device and a sniffling probe connected thereto via a tube. A visual display is located on the sniffling probe. A tactile indicator is provided in a handle. An acoustic indicator is arranged on the basic device. The detector can be switched to a detection mode in which the color in the visual display changes and the indicator are activated when a predetermined leakage rate is exceeded. The detector can also be switched to a locating mode in which leakage rate information is displayed by means of a bar of variable length and a sound is generated which has a parameter depending on the leakage rate information.

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: Sniffing probes are frequently used for detecting leaking gases in difficult-to-access and poorly visible environments, for example for detecting a gas leakage in a cooling device of a motor vehicle. It is an object of the invention to improve handling of the sniffing probe. According to the invention, the object is achieved by providing an illumination device (25) at the handle-piece (14) of the sniffing probe (11), which illumination device (25) illuminates the region to be inspected. This considerably facilitates handling of the sniffing probe in difficult-to-access and poorly illuminated regions.

Abstract: A piston compressor comprises a piston (12) which oscillates in a cylinder (14). A compressed-gas supply arrangement is provided which comprises a compressed-gas accumulator (34), a compressed-gas supply line (18) between a compressed-gas source (20) and the compressed-gas accumulator (34). Further, the compressed-gas supply line (18) comprises an inlet valve (42) which is open when the piston (12) is in a filling position. The inlet valve (42) is defined by a cylinder wall opening (22) and a piston wall opening (38) which are located opposite each other when the piston (12) is in the filling position, thus defining an open valve, and which are closed by the piston wall (40) and the cylinder wall (24), respectively, when the piston (12) is in the non-filling position, thus defining a closed valve. Thereby, a valve is provided which does not comprise any moving parts and is thus easy to manufacture, is highly reliable and has a long service life.

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 piston compressor comprises a piston (12) which oscillates in a cylinder (14). A compressed-gas supply arrangement is provided which comprises a compressed-gas accumulator (34), a compressed-gas supply line (18) between a compressed-gas source (20) and the compressed-gas accumulator (34). Further, the compressed-gas supply line (18) comprises an inlet valve (42) which is open when the piston (12) is in a filling position. The inlet valve (42) is defined by a cylinder wall opening (22) and a piston wall opening (38) which are located opposite each other when the piston (12) is in the filling position, thus defining an open valve, and which are closed by the piston wall (40) and the cylinder wall (24), respectively, when the piston (12) is in the non-filling position, thus defining a closed valve. Thereby, a valve is provided which does not comprise any moving parts and is thus easy to manufacture, is highly reliable and has a long service life.

Abstract: Two resistance elements (3, 6) are used for eliminating the influence of wall temperature on the gas pressure in a vessel, determined by a Pirani manometer. The first resistance element (3) is present in a first branch of a Wheatstone bridge (1), and the voltage is tapped by means of a voltage divider (7). The second resistance element (6) is present with a series resistance (5) in the second branch and is adjusted to a lower temperature. The changes in the voltages tapped at the branches are essentially identical for identical temperature changes at the resistance elements (3, 6), so that the Wheatstone bridge (1) remains balanced. The adjustment is improved by a constant current source (11).

Abstract: A measurement amplifier has an integrator circuit (2) and a reference current source (33) which supplies a reference current to the input of the integrator when the voltage set at the output of the integrator (2) exceeds or falls below a reference voltage. In addition, a differentiator, for example, is provided which receives the output voltage of the integrator (2) and supplies an output signal which is proportional to the variation in time of the output voltage of the integrator. The output voltage of the differentiator is proportional to the input current to be measured by the measurement amplifier. The measurement amplifier allows very weak input currents to be rapidly and accurately detected.

Abstract: An electronic circuit for measuring current in a working circuit is provided with a first operational amplifier having a positive input, a negative input, and an output connected to at least one in-line amplifier to form a first current path. A second operational amplifier having a positive input, a negative input, and an output connected to a differential amplifier is provided within the circuit to form a second current path. An input terminal is connected to the negative inputs of each of the operational amplifiers to provide a connection between the electronic circuit and the working circuit. A variable conductance component is connected in series between the input terminal and the negative input of the second operational amplifier to control the flow of variable currents through the two current paths.