Abstract: The present invention relates to a device for measuring the concentration of hydrogen in a gaseous mixture and in particular in the air constituting, for example, the atmosphere inside a closed premises. This device comprises a sensor in contact with a gaseous mixture, the sensor being linked to calculating and display function. The sensor comprises a catalyst capable of provoking an exothermic reaction with the hydrogen contained in the gaseous mixture, a conducting function fixed to the catalyst for transferring essentially by conduction the thermal energy release by the reaction from the catalyst to a cold point, a function for measuring the temperature T1 of the catalyst and the temperature T2 of the cold point being linked to the function for calculating the value of the molar concentration of hydrogen in a gaseous mixture from the temperature gradient measured T1-T2.

Abstract: The invention includes systems and methods which allow reactivation of supported noble metal catalysts. The method involves heating the catalyst in the presence of a gaseous hydrocarbon in the absence of oxidizing agents. Systems of the invention provide for in situ reactivation of catalytic material.

Abstract: An A/F signal proportional to an oxygen concentration in the exhaust gas from an internal combustion engine is output upon application of a voltage based on an instruction from a microcomputer. At the time an element resistance is detected, a bias instruction signal Vr from the microcomputer is converted by a D/A converter 21 to an analog signal Vb. An output voltage Vc obtained by removing high frequency components from the analog signal Vb through an LPF 22 is input to a bias control circuit 40. During this time period in which the element resistance is detected, an accurate A/F signal is not output. Therefore, the A/F signal that has theretofore prevailed is held by a Sample/Hold circuit 70 to thereby prevent the use of an erroneous A/F signal. Namely, at the time of detecting the element resistance, the detected value of the oxygen concentration is prevented from becoming abnormal. As a result, an accurate A/F control can be executed using the detected element resistance.

Abstract: An A/F signal proportional to an oxygen concentration in the exhaust gas from an internal combustion engine is output upon application of a voltage based on an instruction from a microcomputer. At the time an element resistance is detected, a bias instruction signal Vr from the microcomputer is converted by a D/A converter 21 to an analog signal Vb. An output voltage Vc obtained by removing high frequency components from the analog signal Vb through an LPF 22 is input to a bias control circuit 40. During this time period in which the element resistance is detected, an accurate A/F signal is not output. Therefore, the A/F signal that has theretofore prevailed is held by a Sample/Hold circuit 70 to thereby prevent the use of an erroneous A/F signal. Namely, at the time of detecting the element resistance, the detected value of the oxygen concentration is prevented from becoming abnormal. As a result, an accurate A/F control can be executed using the detected element resistance.

Abstract: In this method of analyzing a gas mixture containing at least one inflammable gas to determine its explosibility, a resistive heating element (15) is energized in an analysis enclosure (12) communicating with the gas mixture to be analysed to burn the gas mixture in the enclosure, an electrical signal (S) at the terminals of the resistive element (15) is measured during combustion, and the explosibility of the gas mixture is determined from a comparison of values of the signal measured during a transient phase in which the concentration of the inflammable gas in the gas mixture is falling. The measurements taken during the transient phase are taken at times chosen to obtain, for different inflammable gases, substantially identical measurement signals for concentrations corresponding to identical explosibilities.

Abstract: A sensor for measuring the non-methane HC concentration of gas sample, e.g., automotive exhaust gas, the sensor comprises a sensor base, capable of producing a output signal representative of the exothermic effect of the hydrocarbon species in the gas sample. The sensor base has disposed on, and integral with, its surface, a porous selective oxidation catalyst layer comprising capable of selectively oxidizing a combination of CO+H2+alkene species in the gas sample and leaving unoxidized the alkane and aromatic hydrocarbons. The sensor base further includes a first supported resistance temperature device which has disposed thereon a total oxidation catalyst layer capable of oxidizing the remaining alkane and aromatic hydrocarbon species in the gas sample, and a non-catalyzed second resistance temperature device.

Abstract: The invention relates to a procedure for determining the risk of flammability of a mixture of two reactive gases A, B, in an inert or base gas, characterized in that it comprises:

Abstract: A method and apparatus are disclosed for analyzing the aggregate content of asphalt-aggregate compositions. The method includes placing a preheated, preweighed container carrying a sample of an asphalt-aggregate composition into a preheated furnace with the preheated furnace being warmer than the preheated sample, continuing to heat the furnace while drawing air through the furnace at a rate that avoids impeding the heating of the furnace or the sample until the sample in the container reaches its combustion temperature and the combustion of the sample becomes exothermic, initiating a second draw of air around rather than through the furnace to moderate the exterior temperature of the furnace, accelerating the draw through the furnace to increase the rate of combustion of the exothermic reaction, and reweighing the container and sample after combustion is complete.

Abstract: A system for measuring the non-methane HC concentration of gas sample, e.g., automotive exhaust gas, comprises a sensor catalyst capable of selectively oxidizing the combination of CO+H2+alkene hydrocarbons in a gas sample and a catalytic differential calorimetric sensor downstream of the sensor catalyst, capable of producing an output signal representative of the exothermic effect of oxidation of the remaining aromatic and alkane hydrocarbons in the gas sample. The system also includes a heater for maintaining both the sensor catalyst and the catalytic calorimetric sensor at a temperature sufficient to achieve substantially complete oxidation of the CO+H2+alkene hydrocarbon combination and the aromatic and alkane hydrocarbons, respectively. Lastly, the system includes a means for analyzing the output signal representative of the concentration of unburned aromatic and alkane hydrocarbons in the exhaust gas to determine concentration of the total non-methane hydrocarbon species.

Abstract: A method and apparatus are disclosed for analyzing the aggregate content of asphalt-aggregate compositions. The method includes placing a preheated, preweighed container carrying a sample of an asphalt-aggregate composition into a preheated furnace with the preheated furnace being warmer than the preheated sample, continuing to heat the furnace while drawing air through the furnace at a rate that avoids impeding the heating of the furnace or the sample until the sample in the container reaches its combustion temperature and the combustion of the sample becomes exothermic, initiating a second draw of air around rather than through the furnace to moderate the exterior temperature of the furnace, accelerating the draw through the furnace to increase the rate of combustion of the exothermic reaction, and reweighing the container and sample after combustion is complete.

Abstract: A method and apparatus are disclosed for analyzing asphalt-aggregate compositions. The method includes directing sufficient microwave radiation from a microwave source to a sample of an asphalt-aggregate composition to ignite the asphalt in the composition and to thereafter entirely combust the asphalt in the sample. The apparatus includes a source of microwave radiation, a cavity in communication with the microwave source, a sample holder in the cavity for holding a sample of an asphalt-aggregate composition during exposure to microwaves from the source, thermal insulation between the sample holder and the remainder of the cavity, and means for minimizing or eliminating any undesired combustion products generated by the burning asphalt.

Abstract: A method and apparatus is provided for modulating the flux of oxygen impinging on a calorimetric gas sensor. The method and apparatus are based on modulating the oxygen concentration of a gas mixture presented to the microcalorimeter between a predetermined high level and at a substantially zero value to create a modulated output to reduce the noise of the sensor and to eliminate its zero-offset.

Abstract: A method and apparatus is disclosed for sensing hydrocarbon in the vapor path of fuel dispensers using a fiber-optic sensor. The sensor includes an absorber-expander sensing structure mechanically coupled to the fiber body and responsive to the presence of effluent fuel components for absorbing the hydrocarbon therein and expanding in response thereto. The expansion activity has the effect of generating a microbend deformation in the fiber, producing detectable changes in the optical throughput representing the concentration of hydrocarbon that is sensed by the absorber-expander element. The fiber-optic sensor is particularly useful in a vapor recovery system by providing an optical signal that is representative of the ambient hydrocarbon concentration.

Abstract: A system for measuring the non-methane HC concentration of gas sample, e.g. automotive exhaust gas, comprising first and second catalytic differential calorimetric sensors. The first catalytic differential calorimetric sensor is capable of producing a first output signal representative of the exothermic effect of the oxidation of the predominate oxidizable species (CO+H.sub.2 +non-methane HC combination) in the gas sample. The second catalytic differential calorimetric sensor is capable of producing a second output signal representative of the exothermic effect of the combined oxidation of the CO+H.sub.2 +alkene hydrocarbon species in the gas sample. Lastly, the system includes a means for comparing the first output signal with the second output signal, thereby indicating the total concentration of unburned aromatic and alkane hydrocarbon species in the gas sample which directly correlates to the total non-methane HC concentration.

Abstract: The invention provides a gas sensor for selective detection of hydrocarbons in low-oxygen gases, having a capacitive element and a gas-permeable sensitive layer as a dielectric. The sensitive layer is a precious-metal-doped zeolite which has a regular crystalline structure made of primary pores whose diameter is in the order of the gas-kinetic diameter of the gas molecules to be detected.

Abstract: A device for determining at least one petroleum characteristic of a geologic sediment sample placed in a boat, said device including a first heater heating said sample in a non-oxidizing atmosphere, a measuring component determining hydrocarbon-containing products released after feeding the sample into said first heater, a second subsequent heater heating said sample in an oxidizing atmosphere, a measuring component determining the amount of CO.sub.2 contained in effluents discharged from the two heaters, said CO.sub.2 measuring means include a cell for measuring continuously CO.sub.2 throughout heating of the first and second heaters and a measuring component determining the amount of CO contained in the effluents discharged from the two heaters, and thereby allowing determination of said petroleum characteristic.

Abstract: The invention describes a method and an apparatus for the automated testing of the flash point and can be used for determining the flash point of flammable liquids. In particular, the inventive method makes is possible to automate the phase of preparing and changing the samples. The apparatus described is characterized in that the whole of the test equipment (1) consists of a stationary simultaneous function head (2) and a mobile test insert (3), which can be separated completely from the simultaneous function head (2), the test insert (3), pre-installed, having the temperature sensor (4) and the flash point indicator (5) and contacting elements (6) for producing the electrical connection to the temperature sensor (4) and to the flash point indicator (5) and at least one coupling element (10) for producing the mechanical connection between a stirrer driving mechanism (7) and the stirrer (8) being disposed at the simultaneous function head (2).

Abstract: An apparatus for on-line measuring physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio, comprising means for providing (N)IR radiation in a predetermined spectral range; means for transmitting light at selected wavelengths in the (N)IR spectral region; means for delivering light from said transmitting means to a hydrocarbon product line; means for allowing an optical path length in the hydrocarbon product line; means for detecting the light transmitted through the said optical path; means for providing the obtained signal to be input to processing equipment for spectral analysis and correlating the spectral data to the physical property data of hydrocarbon products such as octane number, cetane number, density, vapour pressure and the like or gasoline/alcohol ratio.

Abstract: A method allowing fast assessment of at least one petroleum characteristic of geologic sediments from a sample of these sediments, said method comprising heating the sample in a non-oxidizing atmosphere, and which method comprises different temperature rise stages; determining at least three magnitudes S.sub.1r, S.sub.2a and S.sub.b representative of the quantity of hydrocarbons contained in said sample, and deducing at least one petroleum characteristic of the geologic sediment from these three magnitudes.

Abstract: The present invention relates to a method for determining at least one petroleum characteristic of a geologic sediment sample heated in a non-oxidizing atmosphere and an oxidizing atmosphere. The sample is heated to a first temperature value below 200.degree. C. for a predetermined period of time and then to a second temperature value ranging between 600 and 850.degree. C. according to a temperature gradient between 0.2.degree. C. and 50.degree. C./min. Carbon dioxide and carbon monoxide are continuously measured during the temperature stages in order to determine at least one petroleum characteristic, wherein said petroleum characteristic comprises a quantity of organic oxygen, inorganic oxygen, total organic carbon, or inorganic carbon.

Abstract: A method and apparatus for determining the calorific value of a combustible gas including passing an amount of gas through a hydrocarbon detection device comprising interconnected first and second measuring cells, the first measuring cell including a catalyzing substance, wherein the first and second measuring cells provide a signal, the signal is integrated to determine a value, and the value is compared with calibrated values to determine the calorific value. In another embodiment, the Wobbe index of natural gas is determined further including determining the density of the gas and calculating the Wobbe index from the calorific value and density.

Abstract: A method of monitoring hydrocarbons concentration in an exhaust gas includes the steps of: sampling exhaust gas on a vehicle, isolating the hydrocarbons from the exhaust gas on a vehicle, and measuring the amount of hydrocarbons isolated from the sample on a vehicle and providing an indication based on the amount of hydrocarbons. A sensor assembly for monitoring the concentration of hydrocarbons in an exhaust gas of a vehicle includes: a hydrocarbon absorbing material placed in a stream of gas on a vehicle, a gas sensor operatively connected with the absorbing material and in the stream of gas and producing a gas signal, and a sensor controller connected to the gas sensor for receiving the gas signal and for determining the amount of hydrocarbons.

Abstract: A method of evaluating at least on type of pollution characteristic in a soil sample contaminated by hydrocarbon compounds, a method wherein the soil sample is first heated in a non-oxidizing atmosphere, then in an oxidizing atmosphere. The method comprises several temperature rise stages from which at least five quantities Q.sub.0, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 are measured, wherein the quantities represent concentrations of hydrocarbon compounds in the soil sample. At least one type of pollution characteristic of the sample is determined from quantities Q.sub.0, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4.

Abstract: In an oxygen analyzer for an industrial process, an automotive type oxygen sensor has a sensor element assembly with an outer thin walled shield containing insulation and surrounding the sensor element of the automotive type oxygen sensor.

Abstract: A transition metal oxide based calorimetric non-methane hydrocarbon sensor (100) is constructed by disposing a transition metal based catalyst (105), preferably chromium oxide (Cr.sub.2 O.sub.3), onto a carrier (101). A temperature measurement device (103) is positioned thermally coupled to the transition metal based catalyst (105). A preferred application includes sensing non-methane heavy hydrocarbons in an automotive exhaust gas stream (803) by exposing a transition metal oxide catalyst based sensor (805) to the exhaust gas stream (803) and providing a signal (811) indicative of a concentration of non-methane heavy hydrocarbons and carbon monoxide (CO). Then, exposing a compensating sensor (807) to the same exhaust gas stream (803) and providing a compensating signal (813) indicative of a concentration of carbon monoxide (CO). By combining the signal (811) and the compensating signal (813), a measure of non-methane heavy hydrocarbons can be provided.

Abstract: A halogenated hydrocarbon (HHC) detector is formed from a silent discharge (also called a dielectric barrier discharge) plasma generator. A silent discharge plasma device receives a gas sample that may contain one or more HHCs and produces free radicals and excited electrons for oxidizing the HHCs in the gas sample to produce water, carbon dioxide, and an acid including halogens in the HHCs. A detector is used to sensitively detect the presence of the acid. A conductivity cell detector combines the oxidation products with a solvent where dissociation of the acid increases the conductivity of the solvent. The conductivity cell output signal is then functionally related to the presence of HHCs in the gas sample. Other detectors include electrochemical cells, infrared spectrometers, and negative ion mobility spectrometers.

Abstract: An analytical system for measuring the concentration of non-methane organic gases within a test sample including methane and non-methane component groups. In one version, a dual column analysis system utilizes a metal column and a porous layer open tubular (PLOT column to separate methane and non-methane organic gases (NMOG). The metal column captures non-methane compounds which are more easily thermally trapped on the metal column, generally higher molecular weight compounds and polar molecule, which prevents these compounds from contaminating the PLOT column. In another version, the system incorporates a single trap in the form of a porous layer open tubular (PLOT) column which the sample mixture is directed through and which traps the NMOG group through adsorption. The methane group passes through the trap and is vented to atmosphere or evaluated using a detector.

Abstract: A method is provided for precisely and concurrently measuring dynamic engine oil consumption and fuel consumption within an internal combustion engine on a real-time basis. Nonradioactive organo- bromine or chlorine compounds are added to the oil in small amounts in their natural isotopic abundance or enriched. Upon complete combustion, the bromine or chlorine is converted into hydrogen bromide (HBr) or hydrogen chloride (HCl), respectively. A tunable diode laser spectrometer is used to determine the trace amounts of the resultant HBr or HCl in the exhaust gases, which continuously flows through a sample cell by the use of a sample line that allows the unimpeded transport of samples, reduces the pressure of the exhaust gas and maintains it at a suitable level for analysis, and prevents the condensation of water vapor in the exhaust gas so as to prevent the dissolution of the tracer compounds in the water condensate.

Abstract: A method for determining the concentration of a monitored gas in the head space of a confined space containing a medium material at a given temperature (T.sub.1), includes the steps of: (a) providing an extracting apparatus having a chamber for receiving a sample volume of the material to be extracted from the confined space; (b) controlling the temperature of the chamber such that the temperature of the chamber is maintained at the given temperature (T.sub.

Abstract: This invention is a process for detecting low levels of nitrogen oxides (NO.sub.x) in a flowing gas stream (typically an exhaust gas stream) and a catalytic NO.sub.x sensor which may be used in that process.

Abstract: A method for the selective detection of liquid phase hydrocarbons in the C.sub.6 -C.sub.16 range includes a matrix comprising a silicone polymer having dispersed therein a conductive carbon black filler of high structure and comprises signaling the presence of hydrocarbon liquid phase when the electrical resistivity of the sensor increases to a preselected threshold level intermediate the vapor and liquid phase resistivities.

Abstract: Apparatus and method for qualitatively and quantitatively analyzing infrared emission from excited molecules in samples of interest is disclosed. Over the wavelength interval from 1 to 5 um, two strong emission bands are observed with a PbSe detector when organic compounds are introduced into an hydrogen/air flame. The band at 4.3 um (2326 cm.sup.-1 is due to the asymmetric stretch of carbon dioxide while the band at 2.7 um is due to both water and carbon dioxide emission. The carbon dioxide emission at 4.3 um is most intense at the tip of the flame, and increases with the amount of organic compound introduced into the flame. For chromatographic application, an optical filter can be used to isolate the 4.3 um emission band. The infrared emission detection system finds application in the determination of total inorganic carbon, chloride and available chlorine in aqueous samples.

Abstract: A quantitative method including separating a mixture of olefins, aromatics, and saturates by supercritical fluid chromatography to obtain an eluent stream that over a first time period contains a mixture of olefins and saturates, and over a second time period contains aromatics, and passing the eluent first to an ultraviolet absorption detector (UV). Importantly, the eluent is irradiated in the UV detector at a wavelength capable of producing an ultraviolet absorbance response of olefins that is independent of specific olefins present, and preferably is substantially similar to a mass detector response for olefins. From a combination of UV and mass response, the mass of the olefins in the mixture of olefins and saturates can be determined. Thereafter, the eluent is passed to a mass detector whereby the mass of the mixture of saturates and olefins is determined and then the mass of the aromatics is determined.

Abstract: A method for analyzing fluid by a multi-fluid modulation mode is characterized by subjecting a plurality of sample fluids (which may be different or a single sample fluid divided into a plurality of systems) to a fluid modulation by reference fluids at various frequencies, respectively. An analytical portion provided with only one sensor is simultaneously and continuously supplied with the respective sample fluids. An output signal from the sensor in the analytical portion is divided into signal components of the respective modulation frequencies for the respective sample fluids to rectify and level, whereby obtaining analyzed values about the respective sample fluids is achieved.

Abstract: A hydrocarbon gas detection system utilizes a heat chamber or oven to maintain the system at a temperature that will support cracking of hydrocarbon gases. A gas chamber which is located inside the oven is used to contain the flow of gases under analysis and to pass these gases over a first temperature sensing device. A catalyzing material is associated with the first temperature sensing device, either by placing it very near the temperature sensing device or by coating the temperature sensing device with the catalyzing material. A second temperature sensing device is located inside the heat chamber or oven, either outside the gas chamber, or inside the gas chamber, but separated from the first temperature sensing device. The output of the first and second temperature sensing devices extend outside of the furnace to measurement and/or display instrumentation. With this system, the gas sample under analysis is passed through the gas chamber and brought into contact with the first temperature sensing device.

Abstract: An industrial process oxygen analyzer, and method of using same, incorporates an automotive oxygen sensor to minimize the criticalness of controlling heater temperature during operation. Higher sensor heater temperature, required to accommodate the automotive oxygen sensor, is achieved by application of higher supply voltage to the sensor heater. Current limiting of the heater supply circuit reduces stress on the sensor heater, even at the higher operating temperature.

Abstract: The invention relates to a method for monitoring and rapid predetermining of the oxygen demand for the combustion of hydrogen sulfide-containing gas mixtures which allows a quick adjustment to changing gas compositions by regulation of the oxygen supply.

Abstract: A sample of a hydrocarbon oil containing asphaltenes is chromatographically analyzed by forming a mixture of the oil with a weak solvent. The mixture is passed in contact with a column of a stationary phase of fine solid particles of fully functionalized material, followed by a weak solvent. The solvent, after recovery from the column, is analyzed for aromatics by UV-absorption of UV radiation in the range 200 to 400 nm. The absorbance of the UV light by the irradiated eluents across the UV wavelength range is monitored and the integral of absorbance is derived as a function of photon energy across the wavelength range. The magnitude of the derived integral in at least one time interval corresponding with aromatics in the eluent from the stationary phase is measured as an indication of the level of aromatics in the oil sample. The weak solvent may be followed by a strong solvent which, in turn, may be followed by a strong solvent which is modified by the addition of a hydrogen bonding solvent.

Abstract: A sensing device 50 comprising an O.sub.2 sensor 22, a pump 37, a compressor 19, and a heater 21 is provided to quickly sense the amount of O.sub.2 in a combustion product gas. A sample of the combustion product gas is compressed to a pressure slightly above one atmosphere by compressor 19. Next, heater 21 heats the sample between 800.degree. C. and 900.degree. C. Next, pump 37 causes the sample to be flushed against electrode 32 located in O.sub.2 sensor 22 6000 to 10,000 times per second. Reference air at approximately one atmosphere is provided to electrode 31 of O.sub.2 sensor 22. Accordingly, O.sub.2 sensor 22 produces a voltage which is proportional to the amount of oxygen in the combustion product gas. This voltage may be used to control the amount of O.sub.2 entering into the combustion chamber 10 which produces the combustion product gas.

Abstract: A sample of a hdyrocarbon oil containing asphaltenes is chromatographically analyzed by forming a mixture of the oil with a weak solvent. The mixture is passed in contact with a column of a stationary phase of find solid particles of fully functionalized material, followed by a weak solvent. The solvent, after recovery from the column, is analyzed for aromatics by UV-absorption of UV radiation in the range 200 to 400 nm. The absorbance of the UV light by the irradiated eluents across the UV wavelength range is monitored and the integral of absorbance is derived as a function of photon energy across the wavelength range. The magnitude of the derived integral in at least one time interval corresponding with at least aromatics in the eluent from the stationary phase is measured as an indication of the level of aromatics in the oil sample. The weak solvent may be followed by a strong solvent which, in turn, may be followed by a strong solvent which is modified by the addition of a hydrogen bonding solvent.

Abstract: Oxygen feed to a Claus plant is controlled by calibrating a hydrocarbon-representative response signal, but not a hydrogen sulfide representative response signal, responsive to the ratio of hydrogen sulfide:sulfur dioxide in effluent from the Claus plant.

Abstract: A detector for measuring free oxygen at ambient temperature in a combustible atmosphere which may be hazardous constructed as a differential thermocouple pair with the first thermocouple junction coated with a catalyst and the second thermocouple junction coated with a non-catalyst. Free oxygen in the combustible atmosphere reacts with the catalyst to liberate heat and thereby raise the temperature of the catalyst coated junction above that of the non-catalyst coated junction. Thus, the increase in temperature of the first thermocouple above that of the second thermocouple is indicative of the free oxygen in the combustible atmosphere.

Abstract: Apparatus for automatically monitoring the flash point of a liquid passing through a conduit which includes a closed equilibrator vessel into which a sample stream of the liquid is confined and volatile vapors therefrom are allowed to saturate air introduced into the vessel, and a combustible gas sensor for measuring the percent lower flammable limit of the resulting gas mixture. The system further includes suitable computing means for automatically calculating the Tag closed cup flash point of the sample liquid based on the temperature of the liquid and on the measured percent lower flammable limit, and controlling the operation of the apparatus. A method of determining the flash point of such a liquid is also disclosed.

Abstract: In a low-pressure testing apparatus for analyzing gas exhausted from cars under a condition in which air pressure is low, an exhaust-gas analyzing device is provided with a dilution tunnel for diluting exhaust gas from cars with air which is under a decompressed condition, the exhaust-gas analyzer is connected to said dilution tunnel at a supply port side thereof and arranged in a low-pressure testing room, and an exhaust intake is open to the air outside of the low-pressure testing room via airtight piping. An influence caused by the fluctuation of pressure within the low-pressure testing room upon the accuracy of anaylsis can be eliminated.

Abstract: A method detects the proportion of combustible gas in a mixture of air with a measuring device which operates by both the heat-tone and heat-conductivity methods. The method permits measurement in the full concentration range with a high degree of accuracy and the lowest possible energy consumption. The measuring device is made small and light and its sensor has a long service life. The method uses one single sensor which operates at a low temperature in the heat-conductivity mode or alternatively, catalytically active at a higher temperature in the heat-tone mode. If the measurement provides a result below a reference value or within a reference value window, measurement continues in the more accurate heat-tone mode. When the gas concentration increases during measurement, in order to avoid ambiguity of the measuring signal and damage to the sensor above a load-limit value, measurement again takes place in the heat-conductivity mode by reducing the temperature of the sensor.

Abstract: An apparatus for analysis of samples containing organic matter, especially of rock from oil drilling mud, including a loading arm hinged at its base to be movable from a tilted position when it receives a sample-bearing cartridge, which fits on the top of the arm, to a vertical position in which the arm can be raised to fit the upper end of the cartridge within a selectively electrically heated and air cooled chamber. A channel for carrier gas, e.g. hydrogen, passes up the arm so that gas passes through the cartridge when it is held in the heating and cooling chamber, and through the heating and cooling chamber and then through a conduit to a burner within an ignition an analysis chamber.In use, the container is heated to pyrolyze the sample and the resultant vapors are entrained in the gas, burnt and analyzed by flame ionization. After which the sample-bearing cartridge is cooled in the heating and cooling chamber.

Abstract: A method of determining heat losses due to incomplete fuel combustion consists in that periodic sampling of fuel combustion products is carried out. The sample is separated into two parts, one of which includes a gaseous phase, and the other, solid and gaseous phases. Oxygen concentration in each part is assessed, after which both parts are heated and burnt up to determine oxygen concentration after burning. Oxygen losses in the gaseous phase and in the mixture of the solid and the gaseous phases are determined, and heat losses due to chemical and total underburning of fuel are defined as the ratio between oxygen losses. Then heat losses due to mechanical underburning of fuel are estimated as the difference of heat losses due to total chemical and mechanical underburning, and chemical underburning of fuel.

Abstract: A method of determining heat losses due to incomplete fuel combustion consists in that periodic sampling of fuel combustion products is carried out. The sample is separated into two parts, one of which includes a gaseous phase, and the other, a solid and a gaseous phases. Oxygen concentration in each part is assessed, after which both parts are heated and burnt up to determine oxygen concentration after burning. Oxygen losses in the gaseous phase and in the mixture of the solid and the gaseous phases are determined, and heat losses due to chemical and total underburning of fuel are defined as the ratio between oxygen losses. Then heat losses due to mechanical underburning of fuel are estimated as the difference of heat losses due to total chemical and mechanical underburning, and chemical underburning of fuel.

Abstract: A method is provided for evaluation of shallow electrical anomalies to determine which are likely to be caused by seepage from a hydrocarbon reservoir at depth. The method involves geochemical lithological, and petrographic analyses of anomalous sediments to determine whether these sediments contain certain features characteristic of seepage-induced anomalies. These features include the following:(1) accumulations of seeped (non-indigenous) hydrocarbons;(2) accumulations of carbonate cements that have .delta..sup.13 C values between -10 and -58.degree./oo;(3) pyrite accumulations in a shallow, porous host rock where the pyrite is distributed within fractures or between original grains with a disseminated or cement-like texture, and where it is not associated with kerogen or coal and is not framboidal in morphology;(4) close proximity of said pyrite and carbonate accumulations; and(50 anomalous (high) induced polarization (I.P.