Abstract: An inexpensive, yet accurate particle matter (e.g., PM) detector is described that combines the features of two different optical particle sensors with a modeling tool to provide a comprehensive, effective air quality measurement instrument (e.g., sensing instrument). The modeling tool enables the use of a combination low cost optical particle sensors, such as a nephelometer and an optical particle counter to determine the amounts of unhealthy particles that are present in air. The sensing instrument determines the total mass loading at specific size breakpoints, such as PM1, PM2.5, and PM10. In some embodiments, the sensing instrument may include gas sensors so that the particular gaseous pollutants can be identified and measured. In some embodiments, the sensing instrument may further include one or more of a humidity sensor, a temperature sensor, and a pressure sensor.

Abstract: Systems, devices, and methods including a processor having addressable memory, where the processor is configured to: determine one or more flight paths for an aerial vehicle, where the determined flight path creates a continuous surface about one or more potential gas sources of a survey site receive a trace gas data from one or more trace gas sensors of the aerial vehicle of the continuous surface as the aerial vehicle flies the determined one or more flight paths; and determine based on the received trace gas data whether a gas leak is present in the received survey site and a rate of the gas leak if present in the survey site.

Abstract: A nuclear logging tool has a housing, one or more neutron sources, one or more shields, and two or more detectors disposed about the housing. Each of the one or more neutron sources is configured to generate neutrons in pulses or continuously and each of the two or more detectors is operable to detect neutrons and gamma rays. The two or more detectors include a first detector disposed at a first distance from a first neutron source and a second detector disposed at a second distance from the first neutron source. The first distance is shorter than the second distance. The first distance and the second distance is measured in the longitudinal direction of the housing. Each shield is operable to absorb neutrons and gamma rays and is disposed inside the housing between one of the one or more neutron source and one of the one or more detectors.

Abstract: A probe for measuring plasma parameters by means of active plasma resonance spectroscopy comprises an external coupling, a balun, an internal coupling, and a probe head. It is provided that the couplings, the balun, and the probe head are integrated in an electrically-insulating substrate cylinder, and the substrate cylinder has a layered structure made from multiple substrate layers along its rotational axis. In this way, a probe for measuring plasma parameters is provided which enables an improved measurement of the plasma parameters, wherein the plasma is influenced as little as possible during the measurement of the plasma parameters.

Abstract: A vaporizer device includes a resistive heating element; circuitry configured to control delivery of electrical power to the resistive heating element from a power source; and a controller configured to perform operations including: receiving inputs representative of a power delivery to the resistive heating element, a temperature of the resistive heating element, and/or a flow rate of air past the resistive heating element; predicting, using the received inputs, an amount of evaporation of the vaporizable material at the resistive heating element; and controlling the power delivery to the resistive heating element in response to the predicted amount of evaporation of the vaporizable material, the controlling including increasing or decreasing an instantaneous power delivery to the heating element such that a target aerosol yield is produced. Related devices, systems, methods, and articles are also described.

Abstract: A substrate processing apparatus includes a substrate processing part that supplies a processing liquid from a processing liquid supply part to a mounted substrate to execute liquid processing, a liquid drainage part that has a recovery channel connected to a storage part that stores the processing liquid and drains the processing liquid used for the liquid processing, and a control unit executes a processing recipe for the liquid processing and a cleaning recipe for cleaning the substrate processing part and the liquid drainage part. The control unit executes a cleaning operation for supplying a cleaning liquid from a cleaning liquid supply part to clean the substrate processing part and the liquid drainage part and subsequently executes a return operation for supplying the processing liquid from the processing liquid supply part to replace the cleaning liquid attached to the substrate processing part and the liquid drainage part with the processing liquid.

Abstract: A method of continuous seismic reservoir monitoring includes receiving a plurality of seismic data sets associated with a reservoir during a period, where the plurality of seismic data sets corresponds to seismic data received at different times during the period. The reservoir includes a plurality of reflectors, where each reflector has a reflection coefficient. For each of the plurality of seismic data sets, the reflection coefficients of the plurality of reflectors are determined by iteratively updating common focus point (CFP) operators associated with the plurality of reflectors and a plurality of acquisition surface locations. The reflection coefficients corresponding to different seismic data sets are compared to determine changes of the reflection coefficients during the period. The changes of the reflection coefficients are displayed.

Abstract: A high-temperature, high-pressure, and low-velocity gas microtube viscosity measuring apparatus that comprises a thermotank, a fluid filtering and measuring device, a micro-pressure difference metering device, and a data acquisition and processing system. The fluid filtering and measuring device includes a filter, a microtube connector, a flow rate measuring liquid storage tank, an automatic micro-flow rate metering device, and an intermediate container connected in series via pipelines. The micro-pressure difference metering device is connected at two ends to pipelines at the two ends of the microtube connector via detection pipelines. The data acquisition and processing system is electrically connected to the micro-pressure difference metering device and the automatic micro-flow rate metering device to receive pressure difference data and flow rate data.

Abstract: Improved gas leak detection from moving platforms is provided. Automatic horizontal spatial scale analysis can be performed in order to distinguish a leak from background levels of the measured gas. Source identification can be provided by using isotopic ratios and/or chemical tracers to distinguish gas leaks from other sources of the measured gas. Multi-point measurements combined with spatial analysis of the multi-point measurement results can provide leak source distance estimates. Qualitative source identification is provided. These methods can be practiced individually or in any combination.

Abstract: A method for determining an estimate of the specific gravity of a fuel for a gas turbine engine is disclosed. The gas turbine engine includes a fuel control valve and one or more fuel injectors. The method includes determining a first estimate of the specific gravity based on an orifice flow model of the fuel control valve. The method also includes determining a second estimate of the specific gravity based on a combined orifice flow model of the one or more fuel injectors. The method further includes recursively filtering the first estimate and the second estimate to determine a third estimate of the specific gravity.

Abstract: Improved gas leak detection from moving platforms is provided. Automatic horizontal spatial scale analysis can be performed in order to distinguish a leak from background levels of the measured gas. Source identification can be provided by using isotopic ratios and/or chemical tracers to distinguish gas leaks from other sources of the measured gas. Multi-point measurements combined with spatial analysis of the multi-point measurement results can provide leak source distance estimates. These methods can be practiced individually or in any combination.

Abstract: Improved gas leak detection from moving platforms is provided. Automatic horizontal spatial scale analysis can be performed in order to distinguish a leak from background levels of the measured gas. Source identification can be provided by using isotopic ratios and/or chemical tracers to distinguish gas leaks from other sources of the measured gas. Multi-point measurements combined with spatial analysis of the multi-point measurement results can provide leak source distance estimates. These methods can be practiced individually or in any combination.

Abstract: The invention relates to a method for cascading and molding an LED filament support based on a support flitch. A plurality of supports may be separated apart from the support flitch as a whole body, thus reducing welded amount and increasing efficiency. The support flitch comprises a group of supports arranged in parallel and numbered as a first support, a second support, a third support, and so on, till an n-th support one after another. According to three different cutting ways, an inner extension section, an outer extension section, an inner connection side, and a middle connection side at the upper side of the support, as well as the inner extension section, the outer extension section, the inner connection side, and the middle connection side at the lower side of the support are cut out respectively, one group or two groups of the cascaded LED filament supports may be obtained.

Abstract: A gas concentration image (i.e., concentration vs. position data) in a cross section through a gas plume is obtained. Such measurements can be obtained by using a 2D array of gas sample inlets, or by moving a 1D array of gas sample inlets through the gas plume. By combining a gas concentration image with ambient flow information through the surface of the gas concentration image, the leak rate (i.e., gas flux) from the leak source can be estimated. Gas samples are simultaneously acquired by filling two or more gas sample storage chambers. This is the default operation mode, which is convenient to regard as recording mode. The other operating mode is a playback mode, where the gas samples in the gas sample storage chamber are sequentially provided to a gas analysis instrument. Gas collection via line pixels can be used to compensate for vertical wind speed variation.

Abstract: A gas concentration image (i.e., concentration vs. position data) in a cross section through a gas plume is obtained. Such measurements can be obtained by moving a 1D array of gas sample inlets through the gas plume. By combining a gas concentration image with ambient flow information through the surface of the gas concentration image, the leak rate (i.e., gas flux) from the leak source can be estimated. Multiple gas analysis instruments can be employed in connection with sweeping a 1-D array of measurement ports through the gas plume in order to reduce analysis time.

Abstract: A gas density monitoring system for high voltage gas circuit breakers. The gas density monitoring system comprising a gas density device mounted directly on a circuit breaker tank end cover. When the gas density device is fully secured to the tank end cover, the gas density device works in conjunction with a self-sealing valve body to provide a self-sealing, direct pathway between the pressurized tank and a sensing element of the gas density device. This pathway permits the gas density device to sense the circuit breaker tank pressure via an angled port through the tank end cover that limits pressure transients that may result from the normal operation of the circuit breaker. The gas density device contact settings may be verified without removal of the density device from the gas circuit breaker or venting the enclosed gas inside the gas circuit breaker to the atmosphere.

Abstract: A vibratory meter (5) is provided, including one or more flow conduits (103), one or more pickoff sensors (105, 105?), and a driver (104). Meter electronics (20) is configured to vibrate the one or more flow conduits (103) using a drive signal including an initial vibration frequency and to receive a pickoff sensor signal from the one or more pickoff sensors (105, 105?) in response, iteratively offset a phase difference between the drive signal and the pickoff sensor signal by a predetermined phase increment and measure a resulting vibrational frequency and amplitude, with the offsetting operatively sweeping the vibration frequency over a predetermined vibration frequency range and therefore generating a plurality of vibration amplitudes and a corresponding plurality of vibration frequencies, and determine a substantially maximum amplitude response in the plurality of vibration amplitudes and designate the corresponding vibration frequency as comprising the resonant frequency.

Abstract: A gas detection apparatus includes: a heating resistor; and an energization control unit which alternately switches a temperature of the heating resistor to two different temperatures. The gas detection apparatus calculates a density of combustible gas contained in the atmosphere using a heating resistor voltage in a high temperature period and a heating resistor voltage in a low temperature period; acquires three or more values of the heating resistor voltage in each target period; obtains a first average value of the values of the heating resistor voltage obtained in the target period of the high temperature period; obtains a second average value of the values of the heating resistor voltage obtained in the target period of the low temperature period; and uses the first and second average values for a calculation of density of the combustible gas.

Abstract: A gas sensor including a metal shell; a detection element main body held by the metal shell; a porous protection layer coated on a leading end portion of the detection element main body; and a protector including a side wall surrounding an element protruding portion of the detection element main body protruding from a leading end of the metal shell. The side wall has introduction holes formed therein which allow gas to be introduced. The porous protection layer includes a first portion; and a second portion provided on a base end side with respect to the first portion and having a progressively reduced thickness in a direction toward a leading end of the detection element. The second portion is disposed closer to the base end of the detection element than the introduction holes in the axial direction.

Abstract: Improved gas leak detection from moving platforms is provided. Automatic horizontal spatial scale analysis can be performed in order to distinguish a leak from background levels of the measured gas. Source identification can be provided by using isotopic ratios and/or chemical tracers to distinguish gas leaks from other sources of the measured gas. Multi-point measurements combined with spatial analysis of the multi-point measurement results can provide leak source distance estimates. These methods can be practiced individually or in any combination.

Abstract: A system for measuring size segregated mass concentration of an aerosol. The system includes an electromagnetic radiation source with beam-shaping optics for generation of a beam of electromagnetic radiation, an inlet sample conditioner with adjustable cut-size that selects particles of a specific size range, and an inlet nozzle for passage of an aerosol flow stream. The aerosol flow stream contains particles intersecting the beam of electromagnetic radiation to define an interrogation volume, and scatters the electromagnetic radiation from the interrogation volume. The system also includes a detector for detection of the scattered electromagnetic radiation an integrated signal conditioner coupled to the detector and generating a photometric output, and a processor coupled with the conditioner for conversion of the photometric output and cut-size to a size segregated mass distribution.

Abstract: A method for measuring specific gravity of a combustible gas includes measuring the refractive index and sound speed of a gas of interest which contains at least one type of gas selected from a hydrocarbon gas, hydrogen gas, and carbon monoxide gas, and computing the value of the specific gravity Da of the gas of interest from Equation (1) below using a value selected as a correction factor x from within a range of 2.4 to 9.3 on the basis of a refractive index converted specific gravity Dn determined from the refractive index and a sound speed converted specific gravity Ds determined from the sound speed: Da=Ds?[(Ds?Dn)/(1?x)]??Equation (1).

Abstract: The invention relates to a device and method for measuring the density of a plasma by determining an impulse response to a high-frequency signal coupled into a plasma. The density, electron temperature and/or collision frequency as a function of the impulse response can be determined. A probe having a probe head and a probe shaft can be introduced into the plasma, wherein the probe shaft is connected to a signal generator for electrically coupling a high-frequency signal into the probe head. The probe core is enclosed by the jacket and has at its surface mutually insulated electrode areas of opposite polarity. A balun is arranged at the transition between the probe head and an electrically unbalanced high-frequency signal feed to convert electrically unbalanced signals into balanced signals.

Abstract: A method of determining energy content using a specific gravity meter double calibrated to measure both molecular weight and relative density.

Abstract: Methods and apparatuses are provided that greatly expand the utility of conventional hollow waveguide-based sensors via either straight, substrate-integrated channels or via meandering (e.g., circuitous, curved or folded optical paths) waveguide sensor designs. Full- or hybrid-integration of the meandering hollow waveguide with light source, detector, and light-guiding optics facilitates compact yet high-performance gas/vapor and/or liquid sensors of the substrate-integrated hollow waveguide sensor.

Abstract: A method validating a particulate monitoring device includes generating a final gas stream having a particulate material concentration that corresponds to a target particulate material concentration, using the particulate monitoring device to measure the particulate material concentration in the final gas stream, and evaluating an accuracy of the particulate monitoring device based on a comparison of the particulate concentration in the final gas stream that was measured by the particulate monitoring device with the target particulate material concentration.

Abstract: A determination oxygen storage amount used to determine whether a catalyst is degraded is a value obtained by applying a correction amount for removing error caused by response delay time of an output signal of an oxygen sensor to an oxygen storage amount calculated every short time. The correction amount is a value that is calculated using slopes stored in memory, i.e., the slopes for the number of storage cycles (>the short time) corresponding to the response delay time, or the like, and becomes more accurate as a value corresponding to the error as the storage cycle becomes relatively shorter with respect to the response delay time and the number of the slopes stored in the memory increases. The necessary storage capacity of the memory is inhibited from increasing excessively even if the number of the slopes stored in the memory is large.

Abstract: Methods and systems for detecting nuclear material concealed within an enclosure are provided. An ionized air density is measured at one or more locations outside of the enclosure. The presence of the concealed nuclear material is detected, for each of the one or more locations, based on a characteristic of the measured ionized air density indicative of concealed nuclear materials.

Abstract: A method is described for measuring a flow of gas passing a flow meter device. The device causes a pressure drop when a gas flows through it. The pressure drop across the device is a measure of the gas flow. The device is configured as a gas permeable tube that has a flow channel on the upstream side along the tube configured so as to decrease the cross-section of the channel downstream of the gas permeable tube. This provides for a minimum volume in the channel upstream of the device's pressure-drop-generating component.

Abstract: The sensor element 110, which can detect the concentration of a specified gas, is held with a housing 102 with a front end thereof exposed. A protective cover 120 includes an inner cover 130 and an outer cover 140, and secured to the housing 102. A ratio ?1/?2 is set to a range from 0.6 to 0.9, where ?1 represents an outer diameter of a portion where an inner gas aperture 134a is formed in the inner cover 130, and ?2 represents an inner diameter of a portion where an outer gas aperture 144a is formed in the outer cover 140.

Abstract: A system and method for combining specific fire barrier materials along with graphic materials and interior aircraft material/parts to lower the heat release and smoke density when tested using the FAA regulated OSU Heat Release and Smoke Density Tests and/or any other test as required by any countries government in order to install graphics onto an aircraft material/part.

Abstract: A system for measuring size segregated mass concentration of an aerosol. The system includes an electromagnetic radiation source with beam-shaping optics for generation of a beam of electromagnetic radiation, an inlet sample conditioner with adjustable cut-size that selects particles of a specific size range, and an inlet nozzle for passage of an aerosol flow stream. The aerosol flow stream contains particles intersecting the beam of electromagnetic radiation to define an interrogation volume, and scatters the electromagnetic radiation from the interrogation volume. The system also includes a detector for detection of the scattered electromagnetic radiation an integrated signal conditioner coupled to the detector and generating a photometric output, and a processor coupled with the conditioner for conversion of the photometric output and cut-size to a size segregated mass distribution.

Abstract: The disclosure relates to a method for monitoring the quality of a fuel containing alcohol in a storage tank (1) including a sump area (8), wherein the density of the fluid present in the sump area (8) of the storage tank (1) is measured and compared to prescribed values characterizing the density of a mixed phase comprising water and alcohol as a function of the composition thereof.

Abstract: A method of measuring density of a sterilant aerosol e.g. aqueous hydrogen peroxide, in a gas stream (such as a stream of air) for the purposes of measuring sterilant dosage comprising: passing a gas stream at flow rate past an electrically heated element and measuring a first cooling effect, passing an aerosol suspended in a gas stream at flow rate past an electrically heated element and measuring a second cooling effect and measuring the difference between the first cooling effect and second cooling effect and correlating the difference with aerosol density. The total dosage can thus be determined. A measured dosage of a sterilant aerosol can be delivered by way of a feedback loop to halt further delivery of sterilant aerosol when the amount of aerosol delivered reaches a predetermined dosage. The methods allow sterilization to be certified.

Abstract: A method for determining a velocity and density of a fluid without requiring the transmission of ultrasound through the fluid, and a system for performing such a method. The method involves the steps of delivering, receiving and analyzing ultrasound pulses sent from a longitudinal and a shear wave transducers to a member that is in contact with a fluid. The ultrasound pulses reflecting between surfaces provide a first ultrasound pulse echo series, that is transmitted, received and processed. The shear wave ultrasound pulses are also delivered through a shear wave transducer at a predesignated angle relative to the interface of the member and the fluid and the results of this are received to obtain a second ultrasound pulse echo series. Reflection coefficients for the first and second ultrasound pulse echo series are then calculated and the density of the fluid and the velocity of sound in the fluids are extracted.

Abstract: An apparatus and method for estimating size segregated aerosol mass concentration in real time and using a single detector. A beam of electromagnetic radiation is passed through a particle stream made of a test or field aerosol. The single detector outputs an electrical signal proportional to the electromagnetic radiation scattered thereupon. The electrical signal may be conditioned to produce an integrated signal for measuring radiation scattered from all the particles in the interrogation volume, a pulse height from an individual particle within the volume, and/or a time-of-flight measurement from the individual particle. The integrated signal can be correlated to particle mass concentration. The pulse height signal and the time-of-flight signal may be converted to infer the size of the individual particle. Attendant size distributions for the particle sizes may also be obtained. Using known or assumed particle properties, the mass concentration may be estimated from the size distribution.

Abstract: A measurement device measures engine oil consumption of an engine lubricated by engine oil. The measurement device includes a sensing pipe housing in which a sulfur dioxide sensing pipe arranged to sense the sulfur dioxide is disposed, an exhaust gas introduction passage connecting the engine and a first end of the sulfur dioxide sensing pipe, and arranged to introduce the exhaust gas from the engine to the sulfur dioxide sensing pipe, and a flow amount measurement device arranged to measure the flow amount of the exhaust gas flowing in the sulfur dioxide sensing pipe. The engine oil measurement device is small in size and able to measure engine oil consumption easily.

Abstract: Provided is an apparatus for detecting a change in a specific gravity of a fluid surrounding the apparatus wherein the fluid moves upwardly and downwardly with respect to the apparatus. The apparatus includes a housing having a top and a plurality of openings for allowing the fluid to enter the housing. A first floatation device is provided having a first specific gravity and being located within the housing. The first floatation device includes a magnet. A second floatation device is provided having a second specific gravity and located within the housing adjacent said first floatation device. The said second floatation device includes a magnet aligned to have the same polarity as the magnet of the first floatation device. A switch fixedly attached to said top, the switch having an open state and a closed state where when one of said magnets is in proximity to the switch, the switch is in a closed state and wherein when both of said magnets are in proximity to said switch, the switch is in an open state.

Abstract: A fluid discrimination apparatus and a fluid discrimination method are provided for carrying out with accuracy a fluid discrimination such as a fluid type discrimination, a concentration discrimination, the fluid existence or nonexistence discrimination, and a fluid temperature discrimination for a discriminated fluid that is stored in a tank or the like. A characteristic measured value as an index value that indicates the characteristics of the fluid to be discriminated is measured, and a discrimination of a fluid is carried out by comparing the fluid discrimination data that indicates the relationship between a fluid that has been measured in advance and a characteristic value of the fluid with the characteristic measured value.

Abstract: A method of analyzing a gas specimen mixture includes measuring the concentrations of inert components in the gas specimen mixture and the pressure and temperature of the gas specimen mixture. A number of sample gas mixtures are generated with varying percentages of hydrocarbon gases, each including the measured inert component concentrations. For each generated sample gas mixture, the method includes calculating the speed of sound therein based on the measured pressure and temperature and the particular percentages of hydrocarbon gases therein, measuring the speed of sound in the gas specimen mixture, and iteratively comparing the measured speed of sound with the calculated speed of sound in different sample gas mixtures until convergence for a particular sample gas mixture. The molecular weight of the particular sample gas mixture is calculated, and set the molecular weight of the gas specimen mixture to the calculated molecular weight.

Abstract: A gas specimen mixture analysis system includes at least one sensor for measuring the concentrations of inert components in the gas specimen mixture, a pressure sensor for measuring the pressure of the gas specimen mixture, and a temperature sensor for measuring the temperature of the gas specimen mixture. A subsystem measures the speed of sound in the gas specimen mixture, and a processing subsystem, responsive to the at least one inert component sensor, the pressure sensor, the temperature sensor, and the subsystem for measuring the speed of sound, is configured to generate a number of sample gas mixtures with varying percentages of hydrocarbon gases, each including the measured inert component concentrations.

Abstract: A gas viscosity sensor comprises a signal processing circuit and a sensor element, including a gas pressure generating system and a differential pressure measuring system in fluid communication therewith, the differential pressure measuring system comprising a measuring chamber (14) bounded by a thin membrane (28), an inlet-outlet channel or orifice interconnecting the measuring chamber to a source of gas for which the viscosity is to be determined, the inlet-outlet channel or orifice having dimensions adapted to provide resistance to the outflow and inflow of gas in the measuring chamber, and a membrane displacement sensor (32) adapted to measure a time dependent displacement of the membrane due to pressure variations in the measuring cavity.

Abstract: The gas absorption/adsorption memory effect in gas analysis can be reduced by controlling gas flow conditions such that the partial pressure of the analyte of interest is held constant, if the measured analyte concentration is within a predetermined range. Keeping the analyte partial pressure constant is helpful for mitigating the memory effect because changes in analyte absorption/adsorption rates tend to be driven by changes in analyte partial pressure. The memory effect can also be mitigated by performing concentration measurements at two or more different gas flow conditions, and employing a mathematical model to estimate true concentration and “memory effect” contributions to measured concentrations at one or more of the flow conditions. The mathematical model can be based on an assumption that the true analyte concentration is independent of flow rate or pressure, while the “memory effect” contribution to measured concentration is inversely proportional to flow rate or pressure.

Abstract: A gas physical quantity detecting device is basically provided with detection element, a detection element chamber and a filter. The detection element is configured to detect a physical quantity of a gas flowing through a gas flow passage. The detection element chamber contains the detection element and configured to supply gas from inside the gas flow passage to the detection element. The filter is arranged between the gas flow passage and the detection element chamber. The filter has a predetermined thickness with the filter being made of a non-hydrophobic material.

Abstract: An acoustic transducer is in contact with a near wall that has a much different acoustic impedance than a fluid. The transducer transmits an acoustic pulse into into the wall (such as a plate, a wall of a tube or a wall of a sample chamber) that is in contact with this fluid. As the acoustic pulse bounces back and forth within this “near wall”, each echo of this original pulse loses the same fraction of energy on each round trip so the echo energy decays exponentially. Knowing the acoustic impedance of the wall material and the reflection intensity at the transducer/wall interface (which is obtained when using air as the fluid), it is possible to calculate the acoustic impedance of an unknown fluid from the slope of a plot of the logarithm of echo energy versus echo number.

Abstract: A system and technique for determining fluid properties includes an ultrasonic transducer 30 on a first surface 42 of a solid member 40. An opposed second surface 44 of the member 40 is in contact with a fluid 25 to be monitored. A longitudinal ultrasonic pulse is delivered through the solid member, and a multiplicity of pulse echoes caused by reflections of the ultrasonic pulse between the solid-fluid interface and the transducer-solid interface are detected and processed by a processing apparatus 22. The apparatus 22 determines the decay rate of the detected echo amplitude as a function of echo number and compares this value to a calibrated decay rate to determine an acoustic property of the fluid. The speed of ultrasound in the fluid is also determined and the fluid density is determined as a function of the speed of ultrasound and the determined acoustic property.

Abstract: A method for determining a present air density for an imaging mechanism is presented. During a first time period: in a determining and storing action, a nominal air density is stored. In an increasing action, a fan input is increased until a known pressure in a cavity coupled to a fan receiving the fan input has been reached. In a determining and storing action, a nominal fan parameter is determined and stored after the known pressure is reached. During a second time period: in an increasing action, the fan input is increased until the known pressure in the cavity has been reached. In a determining action, a present fan parameter is determined after the known pressure is reached. In a calculating action, the present air density is calculated from the present fan parameter, the nominal fan parameter, and either the known pressure or the nominal air density.

Abstract: An apparatus for the continuous measurement of the interchangeability of LPG/Air Mixtures with Natural Gas, having a sensor that measures the relative density (specific gravity) of an LPG/air mixture, and associated controls for gas sampling, signal processing and computation of mixture properties and interchangeability factors. The entire apparatus, gas sampling components, and signal conditioning devices are carried in one or more housings, having one sample gas inlet port and one or more waste gas outlet ports, one gas density sensor, one or more microprocessor-based signal processing units, and one or more connected operator interfaces. The measurement data from the gas density sensor is combined in the microprocessor-based signal processing unit with user-provided information about the properties of the LPG feedstock.

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: An apparatus for the continuous measurement of the interchangeability of LPG/Air Mixtures with Natural Gas, having a sensor that measures the relative density (specific gravity) of an LPG/air mixture, and associated controls for gas sampling, signal processing and computation of mixture properties and interchangeability factors. The entire apparatus, gas sampling components, and signal conditioning devices are carried in one or more housings, having one sample gas inlet port and one or more waste gas outlet ports, one gas density sensor, one or more microprocessor-based signal processing units, and one or more connected operator interfaces. The measurement data from the gas density sensor is combined in the microprocessor-based signal processing unit with user-provided information about the properties of the LPG feedstock.