Abstract: A system and a method for accurately testing gas leak detectors by considering multiple operational parameters as per the standard requirements are disclosed. The system comprises one or more gas cylinders, a test execution chamber, mass flow controllers (MFCs), and a control system. The test execution chamber is connected to the gas cylinders via test gas pipelines and a plurality of valves, and the mass flow controllers. The test execution chamber further comprises a first chamber and a second chamber, which are connected to form a closed cycle, thereby saving consumption of the testing gases. The control system in communication with the mechanized system, thereby controlling the operation of the system for accurately testing the gas leak detector test samples. The performance of the one or more gas leak detector test samples is controlled by adjusting the density of the testing gas to a predetermined value and as per the standard requirements.

Abstract: A method of processing an input data stream including at least one data peak (2), comprising: detecting at least one peak (2) in the input data stream having an apex with an amplitude above a predetermined threshold (4); and extrapolating (30) the segment of the peak which has an amplitude above the predetermined threshold (7, 8), based on a shape characteristic of the peak (2), to estimate the amplitude of the segments of the peak which have an amplitude less than said threshold (15, 16).

Abstract: A method for testing a gas sensor and a gas-measuring device with a testing device for testing the gas sensor provides an improved analysis and evaluation of states of gas sensors. Due to a testing of a gas admission element, by monitoring measuring signals (35, (38) in a time course (400) in conjunction with dispensing (91, 91?, 91?) a quantity of test substance, it is made possible to check whether a gas supply to the gas sensor is possible (to check if the gas diffusion path is open) and given.

Abstract: A method for operating an internal combustion engine is provided, which has a combustion unit, including a combustion chamber; a fresh gas tract; an exhaust tract, including an exhaust gas sensor integrated therein; and a fuel tank system. During an operation of the internal combustion engine, while purge gas is conducted via a purge gas line a hydrocarbon content of the purge gas is ascertained with the aid of the HC sensor, and the mass flow of the purge gas is also ascertained, and a fuel mass flow introduced into the fresh gas tract is ascertained from these values in combination and a quantity of fuel introduced into the combustion chamber and/or into the fresh gas tract with the aid of at least one fuel injector is adapted.

Abstract: The present disclosure relates to a device for measuring the amount of oxygen present in a gas to be analyze. The device includes at least one member for measuring the amount of oxygen, a first inlet in communication with the measuring member for the supply of gas to be analyzed, and an outlet for the discharge of said analyzed gas. The device also includes a second inlet intended to communicate with the measuring member, allowing said device to be supplied selectively with a calibration gas having a known amount of oxygen, such that the measurement of the amount of oxygen present in the calibration gas makes it possible to determine a potential drift of the measurement of said measuring member relative to the actual known amount of oxygen present in the calibration gas.

Abstract: An atmospheric environment monitoring apparatus includes: a communication interface unit which sequentially receives first atmospheric environment measurement data to N-th atmospheric environment measurement data from any one atmospheric environment sensor when a measurement period of an atmospheric environment sensor comes; a data storage unit which stores the first atmospheric environment measurement data to the N-th (N is an integer of 1 or more) atmospheric environment measurement data; and a control unit which checks the total number of the first atmospheric environment measurement data to the N-th atmospheric environment measurement data.

Abstract: Systems and methods for operating an internal combustion engine that includes an oxygen sensor are described. In one example, a voltage that is applied to a heating element of an oxygen sensor is integrated to determine a resistance of the heating element. The resistance of the heating element is the basis for adjusting voltage applied to the heating element during subsequent engine starts.

Abstract: A computer implemented system for a vertical farming system comprising at least a first crop growth module and operating in an environmentally-controlled growing chamber, the control system comprising sensors for measuring environmental growing conditions in the environmentally-controlled growing chamber over time to generate environmental condition data, a device configured for measuring a crop characteristic of a crop grown in the crop growth module of the environmentally-controlled growing chamber to generate crop growth data and a processing device comprising software modules for receiving the environmental condition data and the crop growth data; applying an algorithm to the environmental condition data and the crop growth data to generate an improved environmental growing condition and generating instructions for adjustment of the environmental growing conditions in or around the growth module in the environmentally-controlled growing chamber to the improved environmental growing condition.

Abstract: An electronic device includes a housing having a hole formed therein, an audio device inside the housing and communicating with an outside of the electronic device through the hole, a gas sensor inside the housing and communicating with the outside through the hole, a proximity sensor inside the housing, a wireless communication module inside the housing, and a processor inside the housing. The processor is configured to acquire data associated with air outside the electronic device by using the gas sensor, to recognize a user gesture of starting a proximity call by using the proximity sensor, and to calculate air quality of the outside air based on at least one of data acquired by the gas sensor before the proximity call starting gesture is recognized and data acquired by the gas sensor after a gesture of ending the proximity call is recognized. Other various embodiments are possible.

Abstract: An exhaust gas sensor for detecting a measurement gas component, having a ceramic sensor element fixed in a housing, and a double-walled protective pipe having outer and inner protective sleeves, the inner sleeve enclosing a gas chamber into which the sensor element extends with a segment at the measurement gas side, in the direction of a longitudinal axis of the sensor, and an annular chamber being formed between the outer and inner protective sleeves. The outer sleeve has a cladding surface having at least one opening configured as a swirling element, through which measurement gas can move into the annular chamber with rotation about a longitudinal axis of the sensor, and the inner sleeve has at least one opening that is adjusted and/or functionally optimized, as to a sensitive region of the sensor element, through which opening the measurement gas can move from the annular chamber into the gas chamber.

Abstract: A self-assembled heteroepitaxial oxide nanocomposite film including alternating layers of a first metal oxide having a first melting point and a second metal oxide having a second melting point that differs from the first melting point is formed in an opening formed in a semiconductor substrate. After forming a metal or metal alloy via structure in the semiconductor substrate, first and second thermal treatments are performed to remove each layer of first or second metal oxide providing a nanoporous membrane.

Abstract: A gas sensor includes a sensor element made of an oxygen-ion conductive solid electrolyte, at least one electrode provided to the sensor element so as to contact a measurement gas, and a controller configured to control the gas sensor. The sensor element is heated, by a heater provided to the sensor element, at a temperature higher than an operating temperature set in advance for a predetermined time period at start of the gas sensor, and then the temperature of the sensor element is decreased to the operating temperature.

Abstract: A method for adapting a characteristic curve of a nitrogen oxide sensor of a combustion engine with exhaust gas recirculation having the first nitrogen oxide sensor upstream of an SCR catalytic converter and a second nitrogen oxide sensor downstream of the SCR catalytic converter includes determining that a particle filter is in a regeneration phase, increasing the exhaust gas recirculation rate, interrupting the supply of urea by a urea injection device, acquiring first nitrogen oxide values from signals generated by the first nitrogen oxide sensor, determining that the first nitrogen oxide values are within a first nitrogen oxide interval, acquiring values from second nitrogen oxide signals generated by the second nitrogen oxide sensor, and determining that the second nitrogen oxide values are within a second nitrogen oxide interval, and adapting the characteristic curve of the first nitrogen oxide sensor by the second nitrogen oxide values.

Abstract: Methods and system for concentrating oxygen include providing a portable apparatus having a plurality of sieve beds, each sieve bed in the plurality of sieve beds including a first end and a second end, a reservoir storing oxygen-enriched gas exiting from the second ends of the plurality of sieve beds, a compressor, an oxygen delivery valve communicating with the reservoir via a delivery line, a flow sensor associated with the delivery line, and control electronics adapted to control operation of the oxygen delivery valve; measuring, via the flow sensor, a flow of the oxygen-enriched gas through the sensor and outputting a signal indicative thereof; and controlling, using the control electronics, the opening and closing the oxygen delivery valve to deliver the oxygen-enriched gas from the reservoir to a user based on the signal.

Abstract: Methods and systems are provided for improving operation of a vehicle heating, ventilation, and air conditioning system. In one example, a method may include calibrating a vehicle humidity sensor position inside a cabin of the vehicle by obtaining one or more humidity measurements with one or more personal computing devices positioned inside the cabin, and may further include adjusting operation of the heating, ventilation, and air conditioning system responsive to the calibration. In this way, an interior humidity sensor of a vehicle may be regularly calibrated, which may improve operation of the vehicle heating, ventilation, and air conditioning system, and may further increase fuel economy.

Abstract: Systems, devices, and methods for adjusting tuning settings of tunable components, such as tunable capacitors, can be configured for calibrating a tunable component. Specifically, the systems, devices and methods can measure a device response for one or more inputs to a tunable component, store a calibration code in a non-volatile memory that characterizes the device response of the tunable component, and adjust a tuning setting of the tunable component based on the calibration code to achieve a desired response of the tunable component.

Abstract: A determination device determining malfunction of a humidity sensor includes a malfunction determination portion. The humidity sensor includes a humidity detector, a temperature detector and a heater. The humidity detector has a humidity-sensitive film in an intake passage and detects a relative humidity of intake air taken into an internal combustion engine for a vehicle. The temperature detector detects a temperature of the humidity-sensitive film. The heater heats the humidity-sensitive film and the temperature of the humidity-sensitive film is increased by the heater. The malfunction determination portion estimates an estimated relative humidity at a subsequent temperature from an original relative humidity and the subsequent temperature, and compares the estimated relative humidity at the subsequent temperature and an actual subsequent relative humidity to determine malfunction of the humidity detector.

Abstract: An engine control device of a vehicle engine includes a processor that detects an operation state of the engine and controls an output of a heater which heats an intake air oxygen concentration sensor detecting oxygen concentration of intake air of the engine. The intake air includes a portion of exhaust gas recirculated to an intake passage of the engine as EGR gas. The processor controls the output of the heater, according to a detected operation state of the engine, so that the intake air oxygen concentration sensor enters one of (i) an active state where a temperature of the intake air oxygen concentration sensor becomes greater than or equal to an activation temperature, (ii) a semi-active state where the sensor temperature is lower than the activation temperature and higher than an inactivation temperature, and (iii) an inactive state where the sensor temperature is lower than the inactivation temperature.

Abstract: A mass spectrometer for analyzing a sample may include an analysis chamber for analyzing the sample and a first vacuum pump operably connected to the analysis chamber, wherein the first vacuum pump operates to create a first vacuum state. The mass spectrometer may also include a sample-preparation chamber operably connected to the analysis chamber and a second vacuum pump that operates to create a second vacuum state, wherein the first vacuum state is a lower pressure than the second vacuum state. The second vacuum pump may be operably connected to the first vacuum pump in a first configuration, and the second vacuum pump may be operably connected to the sample-preparation chamber in a second configuration.

Abstract: In order to make it possible to accurately measure the HF concentration in a BHF solution in a low concentration region using a simple structure, there are provided a relationship storage unit that stores relationships between a pH of a BHF solution and an HF concentration, a pH meter that measures the pH of the BHF solution, and a concentration calculation unit that refers to relationships stored in the relationship storage unit, and calculates the HF concentration from the pH values measured by the pH meter.

Abstract: Methods for optimizing exhaust gas system regeneration and cleaning are provided. The exhaust gas system can include an exhaust gas stream supplied by an exhaust gas source to a particulate filter device through an exhaust gas conduit, and a gas sensor having a sampling end disposed within the exhaust gas conduit upstream from the particulate filter device. The methods can include detecting a gas sensor malfunction, detecting particulate filter device soot loading, and performing an optimized maintenance utilizing at least one common technique. A common technique is one which is capable of cleaning a gas sensor and regenerating a PF device. The exhaust gas source can comprise an internal combustion engine and the at least one common technique comprises a post-injection strategy. Systems for performing the disclosed methods are also provided.

Abstract: A device (118) for automatically calibrating an analyzer (112) used for mud gas or fluid logging, comprising: a cabinet (140) having a plurality of dedicated reception slots (144), each slot (144) being configured for the insertion of a canister (148) containing a known calibration mixture, the cabinet (140) containing: a main line (174) to be connected to the analyzer (112), a connection assembly able to selectively connect each reception slot (144) to the main line (174), a control unit (151) for controlling the connection assembly to successively connect at least two successive slots (144) to the main line (174).

Abstract: Methods and systems are provided for diagnosing sensors in an engine intake by utilizing in an evaporative leak check module pump (ELCM pump). In one example, during engine off conditions, the ELCM pump in an evaporative emission system of the vehicle may be operated in a pressure mode to flow ambient air from the evaporative emissions system to the intake manifold. During humidity sensor diagnostics, the air flow may be used to generate water vapors within the intake manifold, and humidity sensor may be rationalized by monitoring an output of the humidity sensor; and during MAF sensor diagnostics, MAF sensor may be rationalized by monitoring if the MAF sensor output corresponds to a flow rate generated by the ELCM.

Abstract: A device produces an electrical signal in response to a stimulus. The device is formed of a flexible substrate including a layer of fibers, for example, paper, and a solution of dispersed carbon nanotubes coated onto and within the fibers, the solution evaporated to leave carbon nanotubes intertwined within the layer of fibers. The carbon nanotubes are functionalized to be optimized for producing an electrical signal for a particular stimulus, where the stimulus includes exposure of the device to a particular gas or vapor. A number of such devices, some or all of which can be different, are housed together, for producing a complex electronic signal, or for sensing any of a wide variety of stimulus.

Abstract: A method and device for measuring a substance's concentration in a fluid. The method includes first passing a sample to be measured through a chemical sensor at least twice and recording the response value each time; forming a simultaneous equation set using the equation relation between the response value obtained during each measurement and the concentration of the substance, and the mass equation relation satisfied by the concentration change caused by a physical, chemical reaction during each measurement and by the change of the mass, electric quantity, and heat; solving for the concentration of the substance measured and the sensor calibration parameter. The method, used as an absolute measurement method, can be applied to calibrate the sample concentration of a fluid, overcomes the effects on the measurements caused by temperature, humidity, pressure, and some interfering gas, requires no sensor calibration, and substantially enhances the measurements' stability and reliability.

Abstract: A confined space entry station is disclosed. The station has a back plate, an accessory holder, and a probe holding arm. The back plate is configured to attach to a manway of a confined space. The accessory holder is connected to the back plate. The probe holding arm has a connecting segment and a probe holding segment. The probe holding arm has a deployed position and a stored position. The connecting segment is connected to the probe holding segment. The probe holding segment is transverse to the connecting segment. The connecting segment is pivotally connected to the back plate and extends beyond the back plate when the probe holding arm is in the deployed position. The probe holding segment has a surface for supporting a probe. The probe holding segment extends transverse to the back plate when the probe holding arm is in the deployed position.

Abstract: A method for calibrating an exhaust gas sensor arranged in a measurement chamber, includes providing a measurement chamber in or adjacent to an exhaust channel of an internal combustion engine. At the start of a calibration phase, exhaust gas present in the measurement chamber is displaced by a filling of the measurement chamber with calibration gas, and at the end of the calibration phase, exhaust gas diffuses into and/or is introduced into the measurement chamber.

Abstract: An exemplary embodiment of the present invention provides a simultaneous multipoint testing system for analyzing the composition of a fluid in a duct. The system can comprise a plurality of probes each having a plurality of sample legs at different locations within the duct. Each probe can also comprise a mixing chamber for mixing fluid samples collected by each of the sample legs. The system can further comprise a global mixing chamber configured to receive the mixtures of fluid samples from each probe mixing chamber and mix those fluid samples to create a global fluid sample. The system can further comprise an analyzer configured to receive at least a portion of the global fluid sample and measure levels predetermined compounds present in the at least a portion of the global fluid sample.

Abstract: The invention relates to a method and to a regulating device for regulating an air-fuel ratio of an internal combustion engine (10), wherein an exhaust-gas composition of an exhaust gas of the internal combustion engine (10) is determined by virtue of an actual probe signal, which is dependent on the exhaust-gas composition, being detected by means of an exhaust-gas probe (22) and the exhaust-gas composition being determined as a function of the actual probe signal by means of a characteristic curve or a calculation rule, and wherein the determined exhaust-gas composition is compared with a setpoint value or a threshold value, the attainment or exceedance of which triggers a manipulation of the air-fuel ratio supplied to the internal combustion engine (10), wherein, in order to take into consideration at least one disturbance variable which affects the actual probe signal, a safety margin (?S) is defined which is applied to the characteristic curve or calculation rule, to the actual probe signal or to the set

Abstract: A method and test devices are used for field calibration of gas detectors. Brand new gas detectors are used as measurement standards in field calibration. The brand new gas detectors are in this case either employed directly as working standards, in which case the regular calibration by a reference standard is dispensed with, since the brand new gas detectors are always deemed to be sufficiently accurate. Alternatively, the brand new gas detectors are employed directly, namely as sufficiently accurately calibrated reference standards for the reference gas sensors acting as working standards and incorporated into the test device. In both cases the measured values of the gas sensors in the gas detectors to be calibrated are fed back to a sufficiently calibrated system, namely either directly to at least one brand new gas detector as a working standard or else to a reference sensor of a calibrated test device.

Abstract: A particulate matter sensor unit may include a sensor portion of an electrostatic induction type that may be reacted when a particulate matter having electric charge may be passing the vicinity thereof, a protection pad that the sensor portion may be bonded on one side thereof through a conductive paste, an heater electrode that may be formed on the protection pad and burns the particulate matters that may be disposed on the sensor portion to eliminate them, and a sensor electrode that may be formed on the protection pad to transfer a signal that may be generated by the sensor portion to an outside.

Abstract: There is provided a monitoring apparatus that monitors abnormalities in a system including a plurality of components or products. The plurality of components or products respectively include a plurality of types of microcapsules that release, due to specific causes, a plurality of marker chemical substances respectively, the marker chemical substances having respectively different ion mobilities. The monitoring apparatus includes an ion mobility sensor that detects the plurality of marker chemical substances. By detecting the marker chemical substances, the monitoring apparatus is capable of identifying the occurrence of an abnormal state, the type of abnormal state, the occurrence location, the extent of the abnormal state, and the like.

Abstract: A calibration system is provided that supports a plurality of multi-gas detectors and that includes additional options for delivering additional test gases to the detectors. The system can include a calibration module for calibrating a multi-gas detector with a first gas and a replacement module capable of being coupled to the calibration module. When coupled to the calibration module, the replacement module can support delivering a plurality of test gases, not including the first test gas, to the calibration module.

Abstract: To provide a method for manufacturing a sensor element, by which stabilization of an electrode, which is performed prior to inspecting element characteristics, can be performed for a shorter time period and in a more reliable manner than in the conventional. The sensor element includes: an oxygen-ion conductive solid electrolyte layer; a first electrode that is formed on a surface of the oxygen-ion conductive solid electrolyte layer; and a second electrode that is formed in a space provided inside the oxygen-ion conductive solid electrolyte layer, and that is configured to reduce said predetermined gas component. As the pre-treatment, by an external power source, a voltage is applied between the first electrode and the second electrode, to thereby decompose and remove a gas component attached to the second electrode.

Abstract: A test station for a plurality of test gases, includes a main unit (10) with a control (12) and test modules (20), each for a gas measurement device, that exchange data to register a type of gas measurement device and test gas(es) required for the device type. The control sets a schedule for a test using a test gas, or for a plurality of successive tests each with different test gases and carries out the specific test planned according to the schedule, in parallel with tests for all of the test modules for a test gas and determines, as an additional gas measurement device is inserted, based on the particular device type of the additional gas measurement device, whether the currently-running test with the current test gas is suitable for the inserted test module; and if the test gas is suitable, to start the test for this test module.

Abstract: A first voltage (V1) is detected between an auxiliary pump electrode and a reference electrode of an exhaust gas sensor, and a target diagnosis value (SDIAG) is determined as a function of the detected first voltage (V1). A measured current (Im) is detected between a measurement electrode and a second main pump electrode of the exhaust gas sensor, said measured current being set up as the pump current by regulating a second voltage between the measurement electrode and the reference electrode to a pre-defined voltage. An actual diagnosis value (IDIAG) is determined as a function of the detected measured current (Im). An error (ERR) of the exhaust gas sensor is recognized depending on the target diagnosis value (SDIAG) and the actual diagnosis value (IDIAG).

Abstract: A method is described for diagnosing a heatable exhaust gas sensor of an internal combustion engine, in which a predefined chronologically varying or constant voltage or a predefined chronologically varying or constant current is generated with the aid of a voltage source, the voltage or the current is applied to terminals of the exhaust gas sensor, a current or applied voltage, which flows through the voltage source when the voltage or the current is applied, is detected, and the current or the voltage is analyzed to diagnose the exhaust gas sensor.

Abstract: When a detection signal obtained from the cell of a gas sensor (S15) has reached a start determination value (specifically, when the output voltage of the cell is higher than 600 mV (S16: YES) or lower than 300 mV (S17: YES)), a pulse voltage is applied to the cell (S18), and a start-time internal resistance is obtained on the basis of the detection signal having changed as a result of application of the pulse voltage (S20). The start-time internal resistance is compared with a deterioration determination value set in advance (S21). A target resistance of the cell used in temperature control (energization control) for the heater is corrected in accordance with the result of the comparison (S28). Thus, the temperature of the cell can be stably maintained constant irrespective of deterioration of the cell.

Abstract: Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor in varying ambient humidity conditions. The learned zero point is corrected based on an estimated ambient humidity to calibrate the reading for dry air conditions or standard humidity conditions. EGR control is performed by comparing the output of an intake oxygen sensor during EGR conditions relative to the humidity-corrected zero point.

Abstract: A method for measuring the concentration of a gas component in a measurement gas using a gas analyzer comprises varying the wavelength of the light of a wavelength-tunable light source within periodically consecutive scan intervals for wavelength-dependent scanning of a gas component absorption line of interest. The method also comprises modulating the wavelength of the light of the wavelength-tunable light source with a frequency, guiding the modulated light through the measurement gas onto a detector and demodulating a measurement signal generated by the detector in the event of a harmonic of the frequency. The method further comprises producing a measurement result by fitting a desired curve to the profile of the demodulated measurement signal. A function orthogonal to the desired curve is provided, and an orthogonal component of the measurement result is produced by fitting the orthogonal function to the profile of the demodulated measurement signal.

Abstract: A method and apparatus for background cancellation for electronic noses to make automated aroma analysis practical in complex field environments. The system and methods compensate for background contaminants while automatically emphasizing all constituents, be they chemically identified or not, which represent information content in the sample being tested.

Abstract: An apparatus for cleaning a detector comprising a housing and a bowl connected to the housing having a detector chamber adapted for enclosing a detector to be cleaned, a contacting surface positioned on the bowl, and one of more air nozzles positioned within the detector chamber for directing one or more bursts of compressed air at a detector to clean the detector, and a fan positioned within the housing operable to draw air within the detector chamber into a filter, and a dust collector for containing dirt and debris dislodged from a detector during the cleaning operation.

Abstract: Apparatus for testing a hazard detector, the apparatus comprising electrically-powered generating means arranged to generate at least two stimuli for application to the detector; and control means arranged to control the generation of each stimulus by said stimulus generating means, wherein said generating means includes a carbon monoxide generator.

Abstract: A system for improving operation of an engine having a particulate matter sensor is presented. The system may be used to improve engine operation during cold starts especially under conditions where water vapor or entrained water droplets are present in vehicle exhaust gases. In one embodiment, particulate sensor degradation is indicated in response to an output of said particulate matter sensor staying below a threshold as engine temperature increases past the dewpoint temperature.

Abstract: A method for determining a polarization of a pump cell and/or a Nernst cell of a lambda probe for the diagnosis of the broadband lambda probe. A voltage or current pulse is applied to the pump/Nernst cell in a first method task, and, in a second method task, a voltage at the pump cell and/or the Nernst cell, or a variable that is related to the polarization or its time characteristic is determined and used as a measure of the polarization, and the function of the broadband lambda probe is monitored via the ascertained polarization. The determination of the polarization may be performed as a voltage measurement performed once or multiple times, or by determining the effect of the polarization in an associated controller, such as a pump current controller of an engine control unit. The variable associated with the polarization may be the reaction of the pump current control.

Abstract: A method and system for detecting, quantifying or characterizing emitting sources. According to an embodiment, an emission source is located by monitoring an area with one or more sensors, determining a plume, generating one or more candidates for the emission source, and using the plume to derive one or more characteristics associated with the emission source, and then locating the emission source based on agreement or convergence of the one or more characteristics.

Abstract: A measured value of a sensor element is obtained during repeatedly executed measuring periods for performing different measurements and for setting different operating states, the sensor element being electrically connected in a periodically alternating manner, in consecutive switching positions, in a predefined order, where at least one measurement for determining the measured value is performed repeatedly within a measuring period for determining individual values at predefined switching positions, the measured value being determined from the individual values. Using the switching position within the measuring period, the operating state of the sensor element preceding the individual measurement, and therefore, the influence of the preceding circuit configuration on the individual measured value, is known, and the individual values are correspondingly corrected. By correcting the individual values, the measured value determined from the individual values is also corrected.

Abstract: A photoacoustic detector wherein control circuits compensate for long term variations of components therein including a light source and sensing microphones. The control circuits intermittently energize the source to evaluate changes in at least source resistance. The control circuits intermittently energize an acoustic generator to evaluate changes in one or more generator responsive microphones.

Abstract: A test station for a plurality of test gases, includes a main unit (10) with a control (12) and test modules (20), each for a gas measurement device, that exchange data to register a type of gas measurement device and test gas(es) required for the device type. The control sets a schedule for a test using a test gas, or for a plurality of successive tests each with different test gases and carries out the specific test planned according to the schedule, in parallel with tests for all of the test modules for a test gas and determines, as an additional gas measurement device is inserted, based on the particular device type of the additional gas measurement device, whether the currently-running test with the current test gas is suitable for the inserted test module; and if the test gas is suitable, to start the test for this test module.

Abstract: A gas-solution equilibrium device for a liquid sample gas analyzer includes a temperature-controlled, thermally-conductive mandrel, a coil of gas-permeable tubing wrapped around the mandrel, the gas-permeable tubing having an inlet and an outlet, and a housing having an internal space containing the temperature-controlled, thermally-conductive mandrel, the coil of gas-permeable tubing and a volume of gas where the gas-permeable tubing has a predefined linear length and a predefined wall thickness, the combination of which together is capable of equilibrating a liquid passing through the coil at a predefined flow rate with oxygen in the atmosphere to provide a gas calibration solution in real time at the outlet of the tubing for the liquid gas analyzer.