Abstract: A gas appliance comprises a combustion device, an ignitor, a gas valve, a blower, a detecting device, and a control device. A control method thereof comprises: the control device is operated in a detection mode in which the control device controls the ignitor to ignite and controls the gas valve as well as the blower to provide a fixed gas flow and a fixed air flow to the combustion device. After igniting the flames, the control device determines burning states detected by the detecting device; if matching a first state, the control device controls the gas valve and the blower in correspondence to a first control data of the first natural gas; if matching the second state, the control device controls the gas valve and the blower in correspondence to a second control data of the second natural gas. In this way, the gas appliance is suitable for burning natural gas generating various heating values.

Abstract: A method for determining properties of a hydrocarbon-containing gas mixture includes determining a thermal conductivity value, density measurement, viscosity measurement, and temperature and pressure. The method also includes determining a hydrogen content of the gas mixture on the basis of the thermal conductivity value and the temperature and pressure, determining a density measurement and associated temperature and pressure, and determining the mean molar mass or standard density on the basis of the density measurement and the temperature and pressure. The method further includes determining the mean molar mass or standard density of a hydrogen-free residual gas mixture based on the mean molar mass or standard density and the hydrogen fraction, determining the Wobbe index of the residual gas mixture based on the viscosity measurement and the temperature and pressure, and determining a calorific value based on the mean molar mass or standard density and the Wobbe index.

Abstract: Embodiments are directed to smoking food in an outdoor grill using a customized smoking routine. In one scenario, an electronic controller of an outdoor grill receives an input to initiate smoke generation according to a specified smoke generation pattern, including: adding a specified amount of combustible pellets to a combustion area within the outdoor grill, such that the combustible pellets begin to burn, measuring a current internal temperature of the outdoor grill and, if below a threshold value, adding a specified amount of additional combustible pellets to the combustion area sufficient to raise the temperature to another threshold value, allowing the internal temperature to cool a temperature below the first threshold value and, upon determining that the temperature of the outdoor grill has cooled below the first specified threshold value, adding additional combustible pellets to the combustion area sufficient to raise the temperature to at least the second threshold value.

Abstract: An apparatus and method for measuring a manual force that uses a pad that simulates human or animal body tissue and a sensor configured to receive the force. The pad can have the shape of a body part and can have different materials that have different hardnesses. The apparatus can have interchangeable pads and identify individual users for training purposes, such as for training massage therapists. The apparatus can indicate whether an applied force is within a predetermined range. Also a method of defining a standard or protocol for training and/or performing touch manipulations by applying a range force to one or more persons with an algometer and establishing a protocol based on data obtained from biosensors attached to the person in order to determine which forces produce a desired effect, such as a reflexive, mechanical, or relaxation effect. The apparatus can then be used to train a provider on how to follow the standard or protocol.

Abstract: A system and method for substantially coincidental sample takeoff flow rate verification which detects unstable flow conditions in a pipeline, terminates fluid sample analysis during flow instability, and resumes sample takeoff when a steady flow state is re-established.

Abstract: A system is provided. The system comprises a computer system comprising at least one processor, a thermodynamic state solver application, and a thermodynamic system solver application. When executed by the at least one processor, the thermodynamic state solver application computes a flash equilibrium state solution for each of a plurality of nodes in a thermodynamic network and determines for each of the plurality of nodes at least one sensitivity of a first thermodynamic property with reference to at least one second thermodynamic property. When executed by the at least one processor, the thermodynamic system solver computes a pressure at each of the nodes and flows between the nodes based at least in part on the sensitivities, wherein a result based on the pressures and flows is determined.

Abstract: The invention relates to a device (1) for determining the combustion value of a fuel. The device (1) comprises a fuel inlet (40) for supplying the fuel to be measured to the device (1). A gas inlet (50) is provided for supplying an oxygen-containing gas to the device (1). The device (1) further comprises a combustion unit connected to the fuel inlet (40) and the gas inlet (50), which combustion unit is provided with a combustion chamber (7) for combusting the fuel to be measured therein. A gas outlet (8) connected to the combustion chamber (7) makes it possible to discharge the combusted gas. The device (1) according to the invention comprises a flow measurement unit (14), preferably of the Coriolis type, disposed between the fuel inlet (40) and the combustion chamber (7).

Abstract: A method of controlling an exhaust gas recirculation system of an internal combustion engine is disclosed. The engine includes a compressor, an intake manifold, an after-treatment system, a low pressure EGR system and a high pressure EGR system. The method temporarily adjusts a low pressure EGR ratio, keeping constant a total EGR rate, after verifying at least one among compressor parameters, after-treatment system parameters or intake manifold parameter.

Abstract: In one aspect, provided herein is a single crystal silicon microcalorimeter, for example useful for high temperature operation and long-term stability of calorimetric measurements. Microcalorimeters described herein include microcalorimeter embodiments having a suspended structure and comprising single crystal silicon. Also provided herein are methods for making calorimetric measurements, for example, on small quantities of materials or for determining the energy content of combustible material having an unknown composition.

Abstract: There is disclosed a method for determining the heating value of a fuel, the fuel comprising at least one hydrocarbon including a first hydrocarbon present in the highest molar concentration, the method comprising: measuring the stoichiometric oxidation molar flow ratio of the fuel; determining the ideal molar heating value (HVm,i) from the measured stoichiometric oxidation molar flow ratio; measuring the molar concentration of the first hydrocarbon; and determining the real molar heating value (HVm,r) from the ideal molar heating value (HVm,i) and the molar concentration of the first hydrocarbon. An apparatus is also disclosed.

Abstract: A calorific value measuring system, includes a gas flowing in a pipe; the flow rate controlling device; a temperature measuring element in the pipe; a heater element, in the pipe, producing a plurality of temperatures; a measuring portion measuring a value from a temperature measuring element that is dependent on the temperature of the gas, and a value from the heater element at each of a plurality of temperatures; an equation storage device storing a calorific value equation using values from the temperature measuring element and values from the heater element at the plurality of temperatures as independent variables and uses the calorific value as the dependent variable; and a calorific value portion calculating a value for the calorific value of a gas through substituting a value from the temperature measuring element and a value from the heater element into the independent variables of the calorific value equation.

Abstract: A method for estimating a heating value of a biological material is disclosed. The method comprises: correlating amounts of radiation transmitted through a number of different reference materials, said radiation being electromagnetic radiation of at least two energy levels, with heating values for said reference materials obtained by calorimeter measurements; irradiating the biological material (102) with electromagnetic radiation of said at least two different energy levels;and measuring the amount of radiation (109a-c) transmitted through said biological material at said energy levels. The method further comprises determining, for each energy level, a transmission value through the biological material based on the radiation through said biological material; and determining, based on said determined transmission values and said correlation, an estimate of the heating value of said biological material. A corresponding apparatus (100) is also disclosed.

Abstract: A transportable Sample Apparatus includes a vacuum flask (Dewar flask) and integral sample container. The Sample Apparatus may be used to capture a liquid phase LNG sample at a custody transfer point and to transport the sample to a laboratory for analysis. Vaporization of the liquid phase sample may take place at a variety of different locations. For example, vaporization may begin and/or be completed during transport from the collection point to the laboratory. In another example, vaporization may begin and be completed in the laboratory. In yet another example vaporization may begin during transport and be completed at the laboratory. The gas phase sample is typically analyzed by a gas chromatograph for Btu content, among other things. Prior to capture of the sample, the Sample Apparatus goes through a pre-cool cycle to chill a sample end cap and other components to a temperature compatible with capture of a cryogenic liquid sample which is about ?250° F.

Abstract: A sample stream of the gas to be analyzed is fed into a combustor. The combustor mixes the gas with ambient air to an over-stoichiometric oxygen content and combusts the sample gas completely. A respective TDLS analyzer measures the CO2 and/or H2O concentration of the combustor's flue gas. In case that the sample gas contains relevant concentrations of CO2 and/or H2O, a second TDLS CO2 and/or H2O analyzer may be added which measures the CO2 and/or or H2O concentration upstream of the combustor. The measurement of methane and ethane or other hydrocarbon and mixtures thereof is also possible. The method and device allows the measurement of the heating value and/or the total organic carbon of a natural gas with high temporal resolution.

Abstract: A combustion calorimeter (1) has a housing (6) and therein a detachably mounted decomposition vessel (2) with sample holder (11) and ignition apparatus (12) in its reaction chamber (3). The wall (4) of the decomposition vessel (2) and also the upper decomposition wall (5) here have in the vertical use position a wall thickness that increases from the bottom to the top in order to conduct the heat generated in a combustion process if possible into the upper region of the decomposition vessel (2), where also at least one temperature sensor (7) can be arranged. Owing to the increase in thickness of the delimitation of the internal or reaction space (3), the heat can be distributed therein more favourably.

Abstract: The present invention describes a scan adiabatic resistive calorimeter (SARC) 1 with ohm heating of the sample 20, which measures the heating enthalpy and is formed of an inner cylinder 11 and a couple of pistons 15 and 16, thus forming said elements a cylindrical chamber hermetically closed 10, which avoids that during its operation can be material losses by leaks. Pistons 15 and 16 have, in one of their ends an electrode 31 and 36 respectively and they pass the electrical heating flow through the sample 20. In reference to this electric flow, the applied power is calculated and therefore, the supplied heat to the sample 20, which is equal to the specific enthalpy. To assure that the whole of the electric flow is conducted through the sample 20, the inner cylinder 11 is electrically isolated.

Abstract: A use composition monitor determines the concentration of peracid and/or peroxide in a use composition using a kinetic assay procedure. A sample mixture containing a sample of the use composition, a diluent and at least one reagent is prepared and analyzed using, for example, an optical detector. A reduced-turbulence optical detector can be used to improve collected response data. A reduced-turbulence optical detector can include a cell body disposed about a length of transparent tubing. The cell body positions one or more emitter/receiver pairs about the transparent tubing. Thus, tube junctions are eliminated and sample flow within the tube is substantially turbulence free.

Abstract: A calorific value measuring system having a container filled with a mixed gas to be measured; a microchip includes a heating element producing heat at a plurality of heat producing temperatures, disposed within the container; a measuring portion measuring a value of an electric signal from the heating element contacting the mixed gas being measured, at each of the plurality of heat producing temperatures; an equation storage device storing a calorific value calculating equation that has, for independent variables, the electric signals from the heating element at the plurality of heat producing temperatures and, as the dependent variable, the calorific value; and a calorific value calculating portion calculating the value of the calorific value of the mixed gas being measured by substituting the measured values for the electric signal from the heating element into the independent variables in the calorific value calculating equation.

Abstract: A method of determining an exit temperature of a gas exiting a combustor of a gas turbine includes determining a mass flow and a temperature of fuel being delivered to the combustor; determining a mass flow and a temperature of air being delivered to the combustor, determining a temperature dependence of the specific heat capacity of a burnt mixture of the fuel and the air being delivered to the combustor; and determining an exit temperature of the burnt mixture exiting the combustor. The exit temperature is determined based on the determined mass flow and temperature of the fuel, the determined mass flow and temperature of the air, and the determined temperature dependence of the specific heat capacity of the burnt mixture.

Abstract: A calorimeter which includes a casing in which a sample is combusted, a jacket around the casing, and temperature sensors in an outer surface of the jacket.

Abstract: A use composition monitor determines the concentration of peracid and/or peroxide in a use composition using a kinetic assay procedure. A sample mixture containing a sample of the use composition, a diluent and at least one reagent is prepared and analyzed using, for example, an optical detector. A reduced-turbulence optical detector can be used to improve collected response data. A reduced-turbulence optical detector can include a cell body disposed about a length of transparent tubing. The cell body positions one or more emitter/receiver pairs about the transparent tubing. Thus, tube junctions are eliminated and sample flow within the tube is substantially turbulence free.

Abstract: A calorimeter (1) with a decomposition chamber (3) with a combustion chamber (2), in which a receiving device (4) for a sample, an ignition device (5), and at least one supply line (6) for oxygen are provided. The decomposition chamber (3) is surrounded by a liquid or water jacket (7) into which at least one temperature sensor (8) extends. The liquid or water jacket (7) is surrounded by an outer container (9), which is a pressure container and which absorbs pressure generated during the combustion of a sample in the decomposition chamber (3) at the walls (10) thereof as a result of a tight sliding fit (15) by way of the water or the incompressible liquid. The decomposition chamber (3) therefore has an accordingly thin wall so that the heat generated during combustion of a sample can reach the temperature sensor or sensors (8) quickly.

Abstract: A calorimeter which includes a casing in which a sample is combusted, a jacket around the casing, and temperature sensors in an outer surface of the jacket.

Abstract: The present invention relates to a process for determining the sensitive or insensitive nature of a crystalline hexogen. Said process comprises: the formulation of said crystalline hexogen in a matrix; the analysis of a sample of said matrix charged with said crystalline hexogen by differential scanning calorimetry; said matrix consisting essentially of at least one liquid polymer that is suitable for the formulation of binders for energetic materials charged with nitro organic explosives; and of at least one adsorbent for the volatile organic compounds, which is stable at the operating temperature of the analysis and which has low affinity for water. The present invention also relates to the crystalline hexogen in such a matrix.

Abstract: An automated apparatus for determining the calorific value of combustible substances employs an integrated, isothermal water reservoir to reduce the complexity of the apparatus and facilitates automation of the calorimeter by providing a convenient source of isothermal water. A moving divider is used to reconfigure the isothermal water reservoir to either provide for temperature equilibration prior to sample analysis or define a fixed volume of water during analysis in which high precision temperature measurements can be recorded. The apparatus includes mechanisms for controlling the moving divider, a sample holding combustion vessel, and loading, cleaning, and unloading the combustion vessel. This eliminates key analysis steps that had previously required manual intervention by an operator.

Abstract: The invention provides a method for measuring the heat release rate of a flame retardardant compound in a microscale combustion calorimeter.

Abstract: A calorimeter includes a bucket cover which is used to reconfigure an isothermal water reservoir to provide for temperature equilibration prior to sample analysis and subsequently define a fixed volume of water during analysis in which high precision temperature measurements can be recorded. The apparatus includes mechanisms for sealing and controlling the cover, and for coupling the combustion vessel to the cover while minimizing the thermal contact between them. Improved thermal isolation between the fixed volume of water and the surrounding environment is also achieved.

Abstract: The invention relates to a method and a device for measuring a gas consumption by means of a gas meter. A gas meter with thermal mass flow sensor for determining mass flow signals (SM) and with a calibration as energy meter for outputting energy value signals (SE) is known. According to the invention, a gas type is determined by the gas meter insofar as combustible and non-combustible gas mixtures are differentiated. The gas meter is operated, in the case of a non-combustible gas mixture, with calibration in mass or standard volume units (I/min) and, in the case of a combustible gas mixture, with calibration in energy units (kWh). Embodiments concern inter alia: measurement of a gas parameter (?, ?, c, ?) of the gas or determining the gas type; gas quality sensor with an identical construction to thermal flow sensor; measuring intervals lengthened in the case of non-combustible gas and shortened in the case of combustible gas.

Abstract: A heating value meter for gases has an outer cylindrical mantle with an outer thermostatic heating apparatus and at least one inlet for introduction of air and at least one inlet for introduction of test or calibration gas. The outer mantle has an outer heating mantle and a bottom part containing an outer sensor of the outer thermostatic apparatus. A cylindrical measuring block is located coaxially inside the outer mantle and is equipped with an axially inserted internal sensor of an electrical remote thermometer of an internal thermostatic apparatus. The heating mantle, the outer sensor, an electrical heating block and an internal sensor, are interconnected via the outer and internal thermostatic apparatus and are adjusted for maintaining a constant temperature by regulation of the electrical input to the electrical heating block, or by the input to the heating mantle where, in addition, the measuring apparatus is connected by an electric lead to the electrical heating block.

Abstract: Thermally analysis of layers and multiple layer structures used in the semiconductor processing arts is disclosed. A modulated calorimetric analysis may be used to determine a thermal signature that characterizes the chemical properties of a sample of material. The signature may include one or more thermal properties such as heat capacities. The signature may be used to compare and infer the suitability of a material for use in an integrated circuit manufacturing process. A thermal signature for a material that is not known to be suitable for manufacturing integrated circuits may be compared with a thermal signature for a standard material that is known to be suitable in order to determine whether the aforementioned material is suitable. Multiple layer structures may also be analyzed, compared, and inferred, and approaches for determining thermal signatures for any individual layer of the multiple layer structure are disclosed.

Abstract: An embodiment of the invention is disclosed that relates to a mechanism for passing a rigid medium under an image-forming mechanism. The mechanism includes a conveyor belt and a number of rollers. The rigid medium travels on the conveyor belt under the image-forming mechanism, for image formation on the rigid medium. The rollers move the conveyor belt.

Abstract: A micro-calorimeter apparatus comprises a thermostated housing (3,4,5); a pair of essentially flat heat sinks (9,10), suspended in said housing (2) and thermally floating relative to the environment inside the housing (3,4,5). The heat sinks (9,10) are arranged with their surfaces facing each other. A pair of Peltier elements (11) are thermally attached to said heat sinks (9,10), one element (11) on each heat sink (9,10), on said facing surfaces, forming a gap between them for the accommodation of a generally flat biosensor unit (12).

Abstract: A method for determining a soot charge in a combustion chamber includes measuring a spatial distribution of at least one parameter characteristic of a combustion by monitoring a flame in the combustion chamber. The at least one parameter allows a conclusion concerning a soot charge in the combustion chamber during operation and the at least one parameter is a temperature and/or a carbon monoxide content. The soot charge is determined based on the measuring step and by using a comparison with given conversion curves. A device for determining a soot charge in a combustion chamber is also provided.

Abstract: The invention concerns a device (10) for measuring calorific energy contained in a fuel gas transported in a pipe (16) comprising a gas meter (12) measuring a volume V in pressure conditions P and temperature conditions T of a gas circulating in said pipe and an apparatus (14;52;63) to determine the gas calorific power H. The invention is characterized in that said apparatus for determining calorific power measures at least one physical variable proportional to the number of molecules of the gas different constituents in a given volume and is placed as near as possible to the gas meter so as to determine the calorific power H(P,T) in similar pressure P and temperature T conditions as those wherein the gas volume V(P,T) is measured, said device then determining the calorific energy H(P,T) V(P,T) contained in the gas.

Abstract: An energy meter which measures a volume of gas supplied, which measures a calorific value of the gas supplied, and which calculates an energy value corresponding to the measured volume of gas supplied and the calorific value. The structure to measure the volume of the gas supplied and to calculate the energy value may be provided in a single unit. The structure to measure the calorific value of the gas supplied preferably includes a structure to measure the speed of sound in the gas and further preferably measures a first thermal conductivity of the gas at a first temperature and measures a second thermal conductivity of the gas at a second temperature which differs from the first temperature, and is arranged to produce the calorific value of the gas corresponding to the measured speed of sound in the first and second thermal conductivities.

Abstract: The invention relates to a method and a device to determine the gas properties of combustible gas, in particular of natural gas, wherein a) at least part of the combustible gas is exposed to infrared radiation and the amount of infrared radiation absorbed by the combustible gas is determined for two wave lengths or spectral ranges, the two wave lengths or spectral ranges being selected so that the amounts of individual components of the combustible gas in their different percentages have an effect on the amounts absorbed and recorded, b) the thermal conductivity is recorded and c) the gas properties are determined from the three measurands. The term gas properties is understood to mean the gas composition, the gross heating value, the Wobbe number, the normal density and the methane number.

Abstract: A calorimeter that measures heat release rates of very small samples (on the order of one to 10 milligrams) without the need to separately and simultaneously measure the mass loss rate of the sample and the heat of combustion of the fuel gases produced during the fuel generation process. The sample is thermally decomposed in a small volume pyrolysis chamber. The resulting fuel gases are immedediately swept by an inert gas stream from the pyrolysis chamber into a combustion furnace in a plug-like flow. This plug flow substantially synchronizes the emerging fuel gases with the mass loss rate of the sample. Oxygen is metered into the fuel gas stream just before it enters the combustion furnace where the fuel gases are completely oxidized. The effluent from the furnace is analyzed to determine the amount of oxygen consumed per unit time and the heat release rate is computed without the need to separately measure the mass loss rate of the sample.

Abstract: A method and apparatus for measuring the calorific value of a gas. The apparatus includes a chamber to which a gas in question, for example natural gas, is supplied through an inlet and leaves through an outlet. The speed of sound SoS at ambient temperature is measured using any suitable method such as electronic control and a calculating device and an ultra-sound emitter and an ultra-sound receiver. The ambient temperatures Ta, is observed by a temperature sensor, and a thermal conductivity sensor measures the thermal conductivity of the gas at two different temperatures above the ambient temperature. One value ThCH, of the thermal conductivity is measured at 70° C. above ambient and the other value ThCL of the thermal conductivity is measured at 50° C. above ambient. The control calculates the calorific value CV of the gas according to the formula: CV=a·ThCH+b·ThCL+C·SoS+d·Ta+e·Ta2 +f, where a, b, c, d, e and f are constants.

Abstract: A calorimeter that measures heat release rates of very small samples (on the order of one to 10 milligrams) without the need to separately and simultaneously measure the mass loss rate of the sample and the heat of combustion of the fuel gases produced during the fuel generation process. The sample is thermally decomposed in a small volume pyrolysis chamber. The resulting fuel gases are immediately swept by an inert gas stream from the pyrolysis chamber into a combustion furnace in a plug-like flow. This plug flow substantially synchronizes the emerging fuel gases with the mass loss rate of the sample. Oxygen is metered into the fuel gas stream just before it enters the combustion furnace where the fuel gases are completely oxidized.

Abstract: The subject of the present invention is: processes for the evaluation and the regulation, to a value P0, of the net (or gross) thermal power P of a flow of a combustible gas CG of composition close to that of a reference gas, said flow of gas passing through a flowmeter (7) of thermal mass technology, which is standardized, or standardized and calibrated, for said reference gas; a method of characterizing a flowmeter of thermal mass technology.

Abstract: Ceramic liners for use with closed bomb devices are disclosed. The closed bomb devices measure performance properties of energetic materials, such as solid propellant, explosive, and pyrotechnic formulations. The closed bomb devices include a body and a ceramic liner. Alumina silicate and boron nitride are two currently preferred ceramic liner materials which have low compressibility, low thermal conductivity, and excellent durability.

Abstract: The fuel heat content of fuel is measured on-line while a combustion turbine system is running by measuring data from the combustion turbine system during combustion of the fuel. The measured data are corrected using a standard correction algorithm. The fuel heat content of the fuel is determined using at least a portion of the corrected data. From the measurement of the fuel heat content, any changes in the fuel heat content are determined. Also, any changes in the control and operational parameters attributable to the change in fuel heat content are determined.

Abstract: The fuel gas or a substream of the fuel gas is passed through a volumetric flowmeter and the volumetric gas flow is measured. In addition, the pressure, temperature and the proportion of at least one inert gas as well as the density and the dielectric constant are measured under reference conditions. The amount of heat supplied to gas consumption devices can be determined from these six parameters reliably without complicated technology.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a body of material (26, 52) which is heated to a temperature sufficient for oxidation of the gas mixture. The size of spaces in a first embodiment of a heater device (9, 11, 25, 26) and in a second embodiment of a heater device (50) are limited to prevent formation of an open flame. In a preferred "lean mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted until a selected power level of combustion at a temperature lower than the point of stoichiometric combustion is reached.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from an oxidation energy ratio determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, in a volume chamber (4) and injected into a combustion device (8, 50) in which a body of inert material (26, 51, 53) is heated above the auto-ignition temperature of the gas mixture. The inert material (26, 51, 53) is arranged to have a void dimension that is small enough to prevent the formation of an open flame during combustion. The process is repeated with a sample gas. During the injection cycle, the microcontroller (12) receives signals which monitor the power of combustion. The microcontroller (12) calculates the heating value of the sample gas and generates an output signal to a visual display or other output device.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a body of material (26, 52) which is heated to a temperature sufficient for oxidation of the gas mixture. The size of spaces in a first embodiment of a heater device (9, 11, 25, 26) and in a second embodiment of a heater device (50) are limited to prevent formation of an open flame. In a preferred "lean mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted until a selected power level of combustion at a temperature lower than the point of stoichiometric combustion is reached.

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 calorimeter is disclosed comprising a sample chamber (12) adapted to enclose a sample, a thermally conductive reference surface (14) surrounding and insulated from the sample chamber (12) and a casing (16) surrounding and insulated from the reference surface. Temperature transducers, in communication with a micro-computer, record the temperatures of the sample chamber (VS) and reference surface (V1) at periodic intervals. The micro-computer is programmed to calculate the theoretical temperature (VT) of the sample chamber from the measured values of the temperature of the reference surface (V1) and estimated values of the thermal power of the sample (I), the thermal resistance from the sample to the sample chamber (RS) and the thermal capacity of the sample (CS), and to optimize the fit between the theoretical calculations (VT) and the corresponding measured values (VS) of the temperature of the sample chamber.

Abstract: An apparatus for measuring the BTU content of a gas includes a source of combustion air, a detector and a sample loop or tube connected to a six-port switching valve. The switching valve allows accurate and repeatable quantities of the gas to be obtained and mixed with the combustion air. In a second embodiment, the apparatus includes a second switching valve to obtain samples of the gas at a second pressure and calculate the BTU content at the second pressure. By measuring the BTU content at two different pressures, a quantity related to the volumetric flow of the gas between the two pressures can also be calculated.

Abstract: The present invention is a method and apparatus for monitoring in real time the mass and energy flow rate of a gas through a pipeline. The invention determines the mass flow ratio of a pipeline gas flowing through a pipeline compared to sample gas tapped from the pipeline line when the volumetric flow of pipeline gas through the pipeline is measured by a linear flow meter. Sample gas tapped from the pipeline is flowed to a chamber having a section with a fixed volume until the pressure in the chamber section is substantially equal to the pipeline gas pressure. The sample gas is maintained at substantially the same temperature as the gas in the pipeline while the sample gas is in the chamber section. A timer measures the time interval for the sample gas to flow from the chamber section at a selected rate for a calculated pressure drop the selected rate being controlled by a flow controller. The mass flow ratio is computed using the measured time interval and a signal from the linear flow meter.