Abstract: The present application discloses a coal consumption online measuring system, which belongs to the field of analysis and measurement technology. The system includes an equivalent atomic number measuring device, a flow rate measuring device, an ash content measuring device, a volatile content measuring device, a moisture content measuring device and a data acquisition and processing device. The data acquisition and processing device iteratively corrects the measured real-time density, real-time ash content, real-time moisture content and/or real-time volatile content; and the data acquisition and processing device performs online calculation of the coal consumption according to a real-time volume flow rate and the iteratively-corrected real-time density, real-time ash content, real-time moisture content and real-time volatile content.

Abstract: An apparatus for evaluating a response time of gas sensors includes: a pipe; a first gas supplier for supplying a first gas to the pipe; a second gas adding machine for adding a second gas to the first gas in the pipe; and gas sensors for detecting components in a mixed gas of the first gas and the second gas, each of the gas sensors being attached to the pipe on a downstream side of an addition position of the second gas in a flow direction of the first gas. The second gas adding machine includes: a supply source of the second gas; a connecting pipe for connecting the supply source to the pipe; and a connecting pipe on-off valve for opening and closing the connecting pipe.

Abstract: The present disclosure relates to an oxidizer, and related methods, for oxidizing polar modifiers in chromatographic mobile phases. The oxidizer enables the use of flame-based detection in chromatographic separations, such as carbon dioxide based chromatography, which employ polar modifiers, such as methanol. Upon exiting a chromatographic column, the mobile phase containing the polar modifier is flowed through an oxidizer that contains a catalyst to oxidize at least a portion of the polar modifier to a species that does not interfere with the function of the flame-based detector. The oxidizer allows for flame-based detection, such as flame ionization detection, in applications in which a polar modifier with a reduced form of carbon is used.

Abstract: The invention relates to a measuring device for detecting the hydrocarbon fraction in gases. The measuring device is characterized in that the measuring device determines the hydrocarbon fraction in a first gas flow and a second gas flow, both the first gas flow and the second gas flow originating from the same gas source, the first gas flow being fed to the measuring device unchanged and the second gas flow being fed to the measuring device prepared.

Abstract: A sampling system includes an analyte sampler that includes an enclosure; a mount disposed in the enclosure; a capillary tube disposed in the mount; and a thermal member disposed in the enclosure and including a first fluid supply member to provide a fluid to an interior of the enclosure. The sampling system also includes a manifold in fluid communication with the analyte sampler. A process for sampling an analyte includes subjecting the capillary tube to a negative pressure; and controlling the temperature of the capillary tube to immobilize the analyte in the capillary tube; providing an analyte to a second end of the capillary tube; and immobilizing the analyte in the capillary tube to sample the analyte.

Abstract: A method for analyzing the liquefied petroleum gas includes the following steps. Provide a sample of the liquefied petroleum gas, and one main component group of the liquefied petroleum gas includes at least one sub component group. Analyze the sample of the liquefied petroleum gas so as to obtain a first measured THC corresponding to the main component group and a second measured THC corresponding to the sub component group. Obtain a regressed THC according to the second measured THC and a predetermined relationship of THC. Obtain a result of THC according to the first measured THC, the regressed THC, and a predetermined range of THC. The predetermined range of THC corresponds to the main component group. The device for analyzing the liquefied petroleum gas includes an inlet, a multiposition valve, a first column, a second column, an analyzing apparatus, and a computing unit.

Abstract: Present invention concerns generally to a sensor or a sensor system for detecting spilling of aqueous liquids, for instance in confined spaces were such is critical such in an airplane. The system of present invention is an early warning system or sentinel for the prevention of corrosion by corrosive liquids. Corrosion caused by corrosive liquids can rapidly change the surface properties of components in engineering structures, and that will finally endanger the functionality of structural parts. However, if monitoring technologies are in place providing continuous information on the presence of corrosive liquids, corrosion treatment and even corrosion prevention can start at a very early stage. Present invention provides such by early detection of corrosive liquids by extended sensors based on the collapse of percolation conductivity (COPC).

Abstract: Hydrocarbon detectors having CNTs coated with an amphiphilic coating capable of sequestering an active molecule are provided. In one aspect, a hydrocarbon detection device is provided. The hydrocarbon detector device includes a plurality of CNTs dispersed in a polar solvent, wherein each of the CNTs is coated with an amphiphilic coating having molecules with a hydrophilic moiety and a hydrophobic moiety, and wherein the coating creates a hydrophobic environment proximal to a surface of each of the CNTs; and one or more hydrophobic active molecules sequestered in the hydrophobic environment proximal to the surface of each of the CNTs.

Abstract: The invention relates to a method for determining a concentration of at least one component of gas present in a gas line or in a gas container, wherein gas is led off from the gas line or the gas container at a measurement location and is supplied to at least one gas flame; the ion flow is measured between a gas flame to which gas is supplied and an electrode arrangement; the temperature of a gas flame is measured to which gas is supplied; and the concentration of the at least one component of the gas present in the gas line or in the gas container is determined from the measurement ion flow and the measured temperature or from values related thereto. The invention furthermore relates to gas concentration sensors for carrying out the method in accordance with the invention.

Abstract: A functional element positioned in front of an active detection region of a sensor element has a compact main body with a gas-side surface, a sensor-side surface, and at least two functional channels located between the gas-side surface and the sensor-side surface. The functional channels have a functionality that is different from one another with respect to a gas that can pass through. Such a functional element allows particularly variable operation of a sensor with great long-term stability.

Abstract: A method and apparatus is provided for concentration determination of at least one component in an acid catalyst for hydrocarbon conversion containing an unknown concentration of an acid, an acid-soluble-oil (ASO), and water. An instrument configured for measuring a property of the acid catalyst, has responsivities to concentrations of one of the acid, ASO, and water, substantially independent of the concentrations of the others of the acid catalyst, ASO, and water. A temperature detector is configured to generate temperature data for the acid catalyst. A processor is configured to capture data generated by the temperature detector and the instrument, and to use the data in combination with a model to determine a temperature compensated concentration of the one of the acid, the ASO, and the water. Optionally, one or more other instruments configured for measuring other properties of the liquid mixture may also be used.

Abstract: A method for analyzing the liquefied petroleum gas comprises the following steps. Provide a sample of the liquefied petroleum gas, and one main component group of the liquefied petroleum gas comprises at least one sub component group. Analyze the sample of the liquefied petroleum gas so as to obtain a first measured THC corresponding to the main component group and a second measured THC corresponding to the sub component group. Obtain a regressed THC according to the second measured THC and a predetermined relationship of THC. Obtain a result of THC according to the first measured THC, the regressed THC, and a predetermined range of THC. The predetermined range of THC corresponds to the main component group. The device for analyzing the liquefied petroleum gas comprises an inlet, a multiposition valve, a first column, a second column, an analyzing apparatus, and a computing unit.

Abstract: The invention relates to a measuring instrument and method for detecting the content of oil, hydrocarbons and oxidizable gases in air or compressed air. In order to develop a measuring instrument for detecting the content of oil, hydrocarbons and oxidizable gases in air or compressed air, said instrument being suitable for detecting concentrations in the lower ?g/m3 range or in the ppb range and allowing measuring accuracy of 10 micrograms oil/m3 air at a measurement error in the single-digit percentage range, it is proposed according to the invention that the measuring instrument comprises an air or compressed-air connection and, connected thereto, a flow limiter to which a catalyst is connected that is connected in turn with a photoionization detector, switchable means being provided for routing the air or compressed air over the oxidation catalyst or past it directly to the photoionization detector.

Abstract: A method for measuring a lower heating value of a gaseous fuel. The method includes mixing a gaseous fuel with air to provide a combustible air-fuel mixture. The air-fuel mixture is directed to flow across a flow surface of a first micro-hotplate maintained at a constant temperature. A change in power required to maintain a constant temperature of the first micro-hotplate flow surface due to a convective and conductive heat transfer from the first micro-hotplate flow surface to the air-fuel mixture is measured. The air-fuel mixture is directed to flow across a flow surface of a second micro-hotplate maintained at a constant temperature. The air-fuel mixture is combusted as the air-fuel mixture flows across the second micro-hotplate flow surface. A change in power required to maintain a constant temperature of the second micro-hotplate flow surface due to the combustion of the air-fuel mixture is measured.

Abstract: A method and apparatus is provided for determining concentration of components in a liquid hydrocarbon mixture including hydrocarbons and water flowing through an alkylation process. A fluid flow path conveys the liquid continuously from the alkylation process through a first instrument configured for measuring a property of the liquid mixture, and having responsivities to concentration of the components, which are independent of the concentration of the water. A temperature detector generates temperature data for the liquid, and a second instrument measures another property of the liquid mixture. The instruments have mutually distinct responsivities to concentrations of the components.

Abstract: A method is provided for controlling the operating temperature of a catalytic reactor using a closed-loop system that provides for varying the reactor input and other operating parameters in order to maintain the operating temperature of the reactor at or near the initial setpoint temperature for operation of the reactor. In one example, maximum and minimum operating temperatures with a catalytic partial oxidation reactor are controlled, as well as maintaining control over the corresponding minimum required ratio of oxygen atoms to carbon atoms, such that the operating temperature within the reactor is maintained below the material limits but above threshold temperatures for coking.

Abstract: Closed-loop control of a hydrocarbon process is provided by an analyzer including an instrument configured for measuring a property of the liquid mixture, and having responsivities to concentrations of one of the components, independent of concentrations of others of the components. A temperature detector generates temperature data for the liquid mixture, and a processor captures data generated by the temperature detector and the instrument, and uses the data in combination with a model of responsivities to various concentrations of the components at various temperatures, to determine a temperature compensated concentration of the components while the liquid mixture flows continuously through the analyzer. A process control module including a process model of the hydrocarbon process, is coupled to the analyzer and is couplable to the hydrocarbon process, to receive the temperature compensated concentration and to generate at least one output configured to affect operation of the hydrocarbon process.

Abstract: A method of operating a furnace having process tubes and multiple burners where it is desired to conform the temperatures of the process tubes to selected target temperature criterion. The present method provides a systematic and quantitative approach to determine how to adjust burner flow rates to result in desired tube wall temperatures, for example to minimize the temperature deviation between tube wall temperatures at a predetermined elevation in the furnace.

Abstract: A method and apparatus is provided for determining concentration of components in a liquid hydrocarbon mixture including hydrocarbons and water flowing through an alkylation process. A fluid flow path conveys the liquid continuously from the alkylation process through a first instrument configured for measuring a property of the liquid mixture, and having responsivities to concentration of the components, which are independent of the concentration of the water. A temperature detector generates temperature data for the liquid, and a second instrument measures another property of the liquid mixture. The instruments have mutually distinct responsivities to concentrations of the components.

Abstract: A total amount of volatile organic compounds (VOCs) in a breath sample (101) is detected by oxidizing/burning (120) the VOCs to form CO2 and H2O, and the amounts of one or both of these compounds are measured (130). CO2 and H2O molecules in the breath sample (101) are removed (110) before the VOCs are converted (120) to CO2 and H2O. Because one VOC molecule contains multiple carbon and hydrogen atoms, the number of formed CO2 and H2O molecules will be substantially larger than the original number of VOC molecules, thereby improving the sensitivity of the detection.

Abstract: A method and apparatus is provided for determining concentration of components in a liquid hydrocarbon mixture including hydrocarbons and water flowing through an alkylation process. A fluid flow path conveys the liquid continuously from the alkylation process through a first instrument configured for measuring a property of the liquid mixture, and having responsivities to concentration of the components, which are independent of the concentration of the water. A temperature detector generates temperature data for the liquid, and a second instrument measures another property of the liquid mixture. The instruments have mutually distinct responsivities to concentrations of the components.

Abstract: The invention relates to a method for determining the smoke point of a hydrocarbon, comprising, among the different steps defined in the ASTM D 1322 standard or equivalents thereof, the identification, among different aspects of the flame according to the position of the burner in the lamp, of a particular aspect of the flame and the reading of the height of this flame on a graduated scale in mm. The invention is characterized by the fact that a series of digital images of the flame is taken and recorded with the aid of a digital camera or the like at intervals sufficiently close for permitting, by analyzing these digital images, the detection of a sudden change in the shape of the flame, and that the height of this flame is measured at the moment of this sudden change in its shape, said height being considered as the smoke point of the tested hydrocarbon.

Abstract: The invention provides a method for producing a homogenous sample of a pressurized fluid stream flowing in a pipeline, the fluid stream consisting of a majority component of hydrocarbon gas, the remainder consisting of one or more hydrocarbon liquids and water in the form of vapor, aerosols, droplets and/or liquid streams, the method includes the steps of: a. injecting one or more surface active agents into the fluid stream in an injection zone at a rate that is sufficient to form a uniform foam of the gas and the one or more hydrocarbon liquids and water components; b. mixing the one or more surface active agents with the fluid stream in a mixing zone to form a uniform foam composition flowing in the pipeline downstream of the mixing zone; c. withdrawing a portion of the foam composition from the pipeline at a sampling point; d. passing the portion of the foam composition withdrawn through a sampling loop; and e.

Abstract: A method and apparatus is provided for determining concentration of components in a liquid hydrocarbon mixture including hydrocarbons and water flowing through an alkylation process. A fluid flow path conveys the liquid continuously from the alkylation process through a first instrument configured for measuring a property of the liquid mixture, and having responsivities to concentration of the components, which are independent of the concentration of the water. A temperature detector generates temperature data for the liquid, and a second instrument measures another property of the liquid mixture. The instruments have mutually distinct responsivities to concentrations of the components.

Abstract: An installation structure for a gas sensor capable of detecting gas concentration in a highly accurate manner is provided. The installation structure for a gas sensor which detects concentration of gas circulating inside an outlet-side piping comprises a through hole 18 in an inner wall of the outlet-side piping and the gas sensor comprises a gas inlet portion with one face open within the outlet-side piping 14, and the gas sensor is installed to the outlet-side piping in a condition where the gas inlet portion does not protrude from the inner wall of outlet-side piping.

Abstract: A process for measuring the mercury concentration within a hydrocarbon is provided that enables the mercury concentration to be measured simply and quickly, and with good reliability and good reproducibility. A process for measuring the mercury concentration within a hydrocarbon includes the steps of placing and weighing the hydrocarbon in a sample boat 12 containing an adsorbent that contains a metal capable of forming an amalgam with mercury, and heating the hydrocarbon inside the sample boat 12 in a combustion furnace 13, together with the adsorbent, and measuring the quantity of mercury within the thus generated gas.

Abstract: A device and method for quantifying an impurity in an input gas stream. The device and method employ a catalyst to convert the impurity to a detectable species in an output gas stream, and the concentration of the detectable species is then measured by means of a detector.

Abstract: The invention relates to a process for the detection of hydrocarbons other than methane in a gas predominantly or essentially comprising oxygen, as well as methane and the said hydrocarbons other than methane, the said process comprising: a stage of detection of the combined hydrocarbons in the said gas, providing a first value for the combined hydrocarbons, a stage of combustion of the hydrocarbons other than methane, a stage of detection of methane in the said gas, providing a second value, a stage of calculation of the amount of hydrocarbons other than methane by the difference between the first value and the second value. The invention also relates to a device for implementing this process.

Abstract: A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 ?m to 5,000 ?m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 ?m to 5,000 ?m is equal to or larger than 80% with respect to an overall weight of the powder filler.

Abstract: Of a gas detector 100, a chamber 105 formed between a center cover 150 and a cover 160 is a part of an air flow channel AF. A first shielding plate 165 is provided in the chamber 105. Water droplets that have entered the chamber from a chamber entrance 103 with air hit and adhere to an entrance-opposed surface 165E of the first shielding plate 165. The water thus adhering to the surface is pushed by the air flowing along the entrance-opposed surface 165E and by gravity, to thereby advance downward. The water then drips downward and is accumulated on a bottom wall surface 105WD which serves as an upper surface of a bottom wall section 161WD. The water is pushed by the flow of air, to thereby advance toward a chamber exit 104. The water is then drained downward from the chamber exit 104.

Abstract: A multi-pin chemiresistor for use in microchemical sensors. A pair of free-standing, bare wires is supported by an electrically insulating support, and are oriented parallel to each other and spaced closely together. A free-standing film of a chemically sensitive polymer that swells when exposed to vapors of a volatile chemical is formed in-between the pair of closely-spaced wires by capillary action. Similar in construction to a thermocouple, this “chemicouple” is relatively inexpensive and easy to fabricate by dipping the pair of bare wires into a bath of well-mixed chemiresistor ink. Also, a chemiresistor “stick” is formed by dipping an electrically insulating rod with two or more linear or spiral-wrapped electrical traces into the bath of well-mixed chemiresistor ink, which deposits a uniform coating of the chemically sensitive polymer on the rod and the electrical traces. These “sticks” can be easily removed and replaced from a multi-chemiresistor plug.

Abstract: A method for quantitative determination of hydrocarbon species in a hydrocarbon sample is disclosed. The method uses Townsend Discharge Nitric Oxide Chemical Ionization Gas Chromatography/Mass Spectrometry.

Abstract: A portable, inexpensive, and easy to operate vehicle oxygen sensor analyzer shows, in real time, on an ultra-bright LED display, the dynamic operation of the oxygen sensor, simulates sensor signals into the computer, while monitoring the oxygen sensor to confirm correct computer operation, and performs a quick, simple and accurate test on the oxygen sensor to prove that it will pass emissions tests for oxygen sensors of the type typically required under emissions control regulations.

Abstract: A method and system for vehicle emission testing measures pollutant concentration, but then provides for conversion of the measured pollutant concentration into its corresponding pollutant mass, thereby allowing for the calculation of a vehicle's emission test scores for one or more common pollutants in units of mass per distance. Through the use of the method and system of the present invention, significantly more accurate results can be obtained as compared to prior art test methods, and without the implementation, operating, and maintenance costs of comparable test methods.

Abstract: A method for determining the heating value of a fuel gas or fuel gas mixture in which the chemiluminescense intensity of at least one chemical bond in a known volume of the fuel gas or mixture is measured. Based upon the results of the measurement(s), the amount of the at least one chemical bond in the known volume of the fuel gas or mixture is determined. Having determined the amount of the at least one chemical bond, the heating value of the fuel gas or mixture can be determined.

Abstract: A method and apparatus for sensing a flammable vapor are described herein. Initially, a first thermal conductivity of a vapor at a first temperature and a second thermal conductivity of the vapor at a second temperature can be determined. Thereafter, a ratio of the first thermal conductivity signal to that of the second thermal conductivity can be calculated to obtain a primary “vapor” signal. The “vapor” ratio can then be compared to an “air” ratio of air without the vapor at the first temperature and the second temperature to obtain a secondary signal thereof. Such a secondary signal can then be compared to an alarm set-point value to thereby determine whether the vapor comprises a flammable vapor and a risk-reducing action thereof be taken.

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: 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: 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, which includes: a step of determining, in the flammability diagram for the A/B/base gas mixture, the change in the composition of the mixture in order to determine whether or not the composition has passed through the flammability region of the flammability diagram, when A is firstly injected into the inert or base gas to form a first mixture and then B is injected into the first mixture in order to form the final mixture; a step of comparing the mixing time, should the region have been passed through, with the chemical induction time for the mixture.

Abstract: A method and apparatus for measuring the concentration of at least one gaseous component and/or vaporous component of a gaseous mixture in which a controlled sensor flame is introduced into the gaseous mixture and at least one narrow spectral band in the controlled sensor flame is optically measured. The concentration of the gaseous component using a result obtained from the optical measuring of the at least one narrow spectral band is then calculated. The method of this invention is particularly suitable for substantially real-time control of combustion processes.

Abstract: A catalytic bead sensor or a semiconductor sensor is operated in a manner in which the power requirement is greatly reduced. The reduction in power is accomplished by operating the sensor at a temperature less than the desired operating temperature in the absence of a combustible gas and increasing to the desired operating temperature when the sensor is exposed to a combustible gas.

Abstract: A hydrocarbon detector (20) includes a gas stream delivery element (26) configured to discharge a carrier gas (70) onto a surface (24). The carrier gas (70) serves to volatilize a hydrocarbon presence (22) from the surface (24). A gas stream recovery element (28) is configured to aspirate a sample gas (78) formed from the carrier gas (70) combined with the hydrocarbon presence (22) volatilized from the surface (24). A hydrocarbon sensor (58) detects the hydrocarbon presence (22) in the sample gas (78) and generates an output signal indicative of the hydrocarbon presence (22). An indicator (80) receives the output signal and indicates the hydrocarbon presence (22) in the sample gas (78). A heat source (72) coupled to the gas stream delivery element (26) heats the carrier gas (70) to further aid in the volatilization of the hydrocarbon presence (22).

Abstract: An exhaust gas sensor includes a housing and a sensor element supported by the housing. The sensor element includes a support member having an exhaust side, a reference side, and an aperture extending through the support member between the exhaust side and the reference side. The sensor element further includes an exhaust-side electrode on the exhaust side of the support member. The exhaust-side electrode is electrically connected to a contact on the reference side of the support member via a lead extending through the aperture. The aperture is sealed around the lead such that gas cannot pass through the aperture. The support member is oriented substantially parallel to the flow of exhaust gases when the exhaust gas sensor is installed on a vehicle. The sensor further includes a contact pin in the housing that engages the contact and biases the sensor element against a portion of the housing.

Abstract: The present invention relates to a device for conditioning a soil or rock sample polluted by hydrocarbons. It also allows conditioning of pure polluting products. The device comprises a receptacle (1) containing a soil or rock sample (3), and an adsorbent material (4a, 4b) for adsorbing hydrocarbons or derivatives. The soil, rock or pollutant sample is preferably surrounded by two adsorbent layers. The invention also relates to a method of analysis by pyrolysis of a soil or rock sample polluted by hydrocarbons wherein the device according to the invention is used.

Abstract: A combustion gas detection apparatus includes a transparent tube partially filled with a combustion gas sensing fluid and an inlet fitting for engagement with the radiator cap of an engine cooling system and an outlet fitting for connection with a vacuum port of the engine or other vacuum source.

Abstract: An exhaust gas sensor includes a housing and a sensor element supported by the housing. The sensor element includes a support member having an exhaust side, a reference side, and an aperture extending through the support member between the exhaust side and the reference side. The sensor element further includes an exhaust-side electrode on the exhaust side of the support member. The exhaust-side electrode is electrically connected to a contact on the reference side of the support member via a lead extending through the aperture. The aperture is sealed around the lead such that gas cannot pass through the aperture. The support member is oriented substantially parallel to the flow of exhaust gases when the exhaust gas sensor is installed on a vehicle. The sensor further includes a contact pin in the housing that engages the contact and biases the sensor element against a portion of the housing.

Abstract: A test kit for testing acidity of a lubricant in a climate control system containing a naphthalimide dye contains an aqueous solution having a salt and a known amount of hydroxide and an organic solution containing an alcohol and an organic solvent having a flash point of at least 130° F. When a lubricant is added to a combination of the aqueous solution and the organic solution, the color of the bottom layer indicates the acid content of the lubricant.

Abstract: A method and apparatus for measuring the concentration of at least one gaseous component and/or vaporous component of a gaseous mixture in which a controlled sensor flame is introduced into the gaseous mixture and at least one narrow spectral band in the controlled sensor flame is optically measured. The concentration of the gaseous component using a result obtained from the optical measuring of the at least one narrow spectral band is then calculated. The method of this invention is particularly suitable for substantially real-time control of combustion processes.

Abstract: A method of controlling the hydrocarbon content of a possible explosive mixture of air/hydrocarbon vapor circulating from an intake point into an installation fitted with a vapor intake system comprising a vapor intake circuit incorporating a suction pump enabling vapor to be circulated at a vapor flow rate QV. A device is connected to the vapor intake circuit to determine the hydrocarbon content of the aspirated vapor comprising a combination of a flow meter on the one hand and a sensor for measuring relative pressure by reference to atmospheric pressure PA on the other. The hydrocarbon content of the vapor circulating in the vapor intake circuit is determined by taking account of the density and the viscosity of this vapor, which is derived on the basis of a characteristic linked to the loss in air pressure previously stored in memory.

Abstract: One of a pair of temperature sensor sections in a combustible gas sensor is covered with porous oxidizing catalytic layers (23, 24) for oxidizing a combustible gas, and the other is not covered with the oxidizing catalyst layers. The temperature sensor sections each have temperature sensitive portions (13, 14) made of a dense ceramic material, resistors (21, 22) buried therein and having a positive resistance temperature coefficient, current leads (31, 32, 41, 42) and voltage leads (33, 34, 43, 44). A method for detecting the deterioration of a catalyst which intends to eliminate the combustible gas, by the use of this combustible gas sensor is further disclosed. When a difference between temperatures of the pair of resistors or a difference between powers fed to the pair of resistors is in excess of a predetermined value, it is judged that the catalyst has been deteriorated.