Abstract: The present invention relates to a method for detecting particles and a particle sensor arrangement. More specifically, the present invention relates to a method and arrangement for detecting particles in a gas flow, e.g. from a diesel combustion engine. The method comprises the steps of; forcing a particle build up on a sensor element of a particle sensor arrangement by regulating the sensor element to a second temperature; wherein the second temperature is lower than a first temperature, the first temperature being the gas flow temperature. Additionally is the particle build up detected at the sensor element by means of a detector. The present invention provides for an accurate method and arrangement to detect and thereby measure particles present in a gas flow, e.g. from a combustion engine.

Abstract: A soot sensor for the detection of soot particles in an exhaust gas flow, having interdigitally engaged measurement electrodes applied on a substrate. An electrical resistance between the measurement electrodes is a measure of soot load of the exhaust gas flow. The measurement electrodes are divided into two regions, a first region in which no soot particles can be deposited and a second region where soot particles are deposited from the exhaust gas flow. The first region and the second region are exposed simultaneously to the other conditions prevailing in the exhaust gas flow.

Abstract: The measurement is conducted by means of thermogravimetric scales (10) bearing at one end of the beam (20) a catalyst body (30) for catalysing a coking reaction of the tars present in the gas state. Precautions are taken in order to ensure homogeneity and regularity of the sampled gas flow and to guarantee predominant catalysis on the catalytic body (30), the weight increase of which gives the weight of the deposited coke and indirectly the content of tars present in the gas state in the gas to be measured. A calorimetric device (34) for analyzing gases from the coking of the tars provides a complementary and/or additional measurement. The solid tars are filtered beforehand, but their content may be measured by an auxiliary device. Possible application to analyzing gases from biomass.

Abstract: A system and method are provided for cleaning combustion soot from an exhaust gas aftertreatment sensor. The system and method determine whether to conduct a sensor desoot event, and if it is determined that a sensor desoot event is to be conducted, the exhaust gas temperature is increased such that the temperature of the sensor correspondingly increases to or above a desoot temperature, the exhaust gas temperature is then controlled to maintain the temperature of the sensor at or above the desoot temperature for a predefined time period, and the exhaust gas temperature is then decreased after the temperature of the sensor has been at or above the desoot temperature for the predefined time period.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate with electrical resistance that varies with temperature and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by heating the substrate in the area between the electrodes and detecting whether resistance varies with temperature as expected, and then cooling the substrate back down and detecting whether resistance varies with temperature as expected. If resistance varies as expected during both heating and cooling, then a validation is diagnosed that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by detecting whether water vapor condensate may be present between the electrodes and if it is, then measuring resistance between the electrodes while subjecting the sensor to conditions sufficient to evaporate any water vapor condensate and diagnosing a validation that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A method for performing on-board functional diagnostics on a soot sensor of a vehicle and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine. The soot sensor is electrically connected to an evaluation circuit with is permanently installed in the motor vehicle. In order to specify a method for performing functional diagnostics on a soot sensor and/or for detecting further components in the soot, with which method it is possible to detect a faulty soot sensor and/or further components in the soot in a cost-effective way, the evaluation circuit measures the temperature coefficient of the soot sensor and detects the defectiveness of the soot sensor and/or the presence of further components in the soot on the basis of the temperature coefficient of the soot sensor.

Abstract: A particulate matter sensor includes a first detection filter provided in an exhaust gas flow passage and capable of collecting particle matter. A second detection filter is provided on a downstream side of the first detection filter in the exhaust gas flow passage and capable of collecting the particle matter. A first differential pressure detection unit is configured to detect a first differential pressure between pressures of an upstream side and the downstream side of the first detection filter. A second differential pressure detection unit is configured to detect a second differential pressure between pressures of an upstream side and a downstream side of the second detection filter. A particle matter amount detection unit is configured to detect an amount of particle matter based on a detection result of the first differential pressure detection unit and a detection result of the second differential pressure detection unit.

Abstract: A particulate matter sensor includes a detection filter, a differential pressure detecting unit, an on-off valve, and a valve control unit. The detection filter is installed in an exhaust passage connected to an internal combustion engine and is configured to detect particulate matter contained in an exhaust gas passing through the exhaust passage. The differential pressure detecting unit is configured to detect a pressure difference between an upstream side and a downstream side of the detection filter. The on-off valve is installed on the upstream side of the detection filter in the exhaust passage and is configured to control a flow of the exhaust gas toward the detection filter. The valve control unit is configured to control the on-off valve to be opened and closed.

Abstract: A system for improving operation of an engine having a particulate matter sensor is presented. The system may be used to improve engine operation during cold starts especially under conditions where water vapor or entrained water droplets are present in vehicle exhaust gases. In one embodiment, an engine controller that activates a heater of an exhaust gas sensor after an output of a particulate matter sensor exceeds a threshold value after an engine is started.

Abstract: A method for on-vehicle functional diagnosis of a soot sensor and/or for detecting further components in the soot in a motor vehicle having an internal combustion engine, the soot sensor connected electrically to an evaluation circuit. To specify a method for functional diagnosis of a soot sensor and/or for detecting further components in the soot, by which it is possible to detect a faulty soot sensor and/or further components in the soot in an economical manner, the evaluation circuit measures a temperature coefficient of the soot sensor and detects the faultiness of the soot sensor and/or the presence of further components in the soot from the temperature coefficient of the soot sensor.

Abstract: A method and system for monitoring a gas turbine engine (20) to predict maintenance requirements. Particles suspended in a gas flow (24, 32) of the engine (20) are monitored and quantified to predict a particle accumulation rate. Monitoring may be done using particle flow sensors (61-63) in a diverted portion (33) of the working gas flow (24), such as in the cooling gas flow (32). Particle sampling (S1-S3) may be done to determine particle size and composition distributions. Particle mass flow rates may then be continuously monitored per engine operating condition, and compared to predetermined values such as a normal upper limit per engine operating condition. An integrated particle mass flow may be used in conjunction with an instantaneous mass flow rate to predict a maintenance requirement. Multiple locations (L1-L3) may be monitored to recognize a maintenance requirement by flow section or component.

Abstract: In a method for determining an NO2 concentration and/or a concentration ratio of NO2 and NO in an exhaust tract of a combustion device, such as an internal combustion engine, an NOx sensor that is sensitive with respect to NO2 and NO is utilized, which provides a NOx output signal correlating with an NOx concentration representing the sum of the concentrations of NO2 and NO. In order to determine the NO2 concentration and/or the concentration ratio of NO2 and NO, the NOx output signal of a first NOx sensor, which is arranged upstream of an exhaust gas treatment element arranged in the exhaust tract and having the capability of converting NO to NO2 and/or converting NO2 to NO, is compared to the NOx output signal of a second NOx sensor, which is disposed downstream of the exhaust gas treatment element.

Abstract: A soot discharge amount is calculated by multiplying a “steady discharge amount” by a “transient correction value.” The steady discharge amount is a soot discharge amount in a steady operation state, and is acquired through table search. For each of a plurality of factors which affect the soot discharge amount, a steady value (value obtained through table search) of the factor and a transient value (current value) of the factor are substituted for a characteristic equation which represents a change in the soot discharge amount with the value of the factor, whereby a steady characteristic value and a transient characteristic value are acquired. The “ratio between the steady characteristic value and the transient characteristic value” is then calculated for each factor. The transient correction value is obtained by multiplying together all values of the “ratio between the steady characteristic value and the transient characteristic value” obtained for the factors.

Abstract: It is used a filter trapping particulates from a gas containing the particulates, a container 5 containing the filter, an upstream pipe 3 provided on the upstream side of the container 5 to lead the gas “A” into the container 5, a downstream pipe 4 provided on the downstream side of the container 5 to lead the gas “B” after the gas passed through the filter, a transmitting antenna 11 to transmit an electromagnetic wave having a frequency of 80 GHz or more and 200 GHz or less, and a receiving antenna 10 to receive the electromagnetic wave. An amount of the particulates trapped in the filter is detected based on an intensity of the electromagnetic wave received by the receiving antenna 10.

Abstract: Proposed is a method for assessing the completeness of a regeneration of a particle filter which is traversed by the exhaust gas of an internal combustion engine, wherein a pressure difference which is generated across the particle filter when a flow passes through the particle filter is measured and evaluated for the assessment. The method is characterized in that a time derivative of the measured pressure difference is formed and the assessment of the completeness of the regeneration takes place as a function of the time derivative.

Abstract: A sensor element for gas sensors for determining the concentration of particles in gas mixtures, especially soot sensors, having at least one measuring device exposed to the gas to be determined, at least one heating element integrated into the sensor element and at least one temperature measurement element integrated into the sensor element, the heating element being situated within the sensor element spatially between the measuring device and the temperature measurement element.

Abstract: A system having a particulate matter sensor in an exhaust stream of an engine upstream from a particulate filter and another such sensor downstream from the filter. There may also be an exhaust gas recirculation (EGR) control on the engine. The amount of particulate matter in or loading of the filter may be determined by the upstream filter. The working condition of the filter may be determined by the downstream sensor. The filter may have a heater and control for providing operational and particulate matter burn-off temperatures to the filter. A processor may be connected to the sensors, the EGR control and the filter heater control.

Abstract: A method of using a burner-based system to produce diesel exhaust gas that contains particulate matter of a desired composition, to simulate the PM matter in exhaust produced by a production-type diesel internal combustion engine.

Abstract: A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

Abstract: A process is disclosed for monitoring the formation of deposits of solid particles in a fuel line having a valve. A measure for the deposits of solid particles in the fuel line is determined by determining the degree of opening of the valve passage and the quantity of fuel flowing through the valve, and by comparing them with a previously determined control value which characterizes the deposit-free line. Also disclosed is a device for monitoring the formation of deposits of solid particles in a fuel line having a valve, the device having a measurement system for determining the current fuel flow and a measurement system for determining the current valve position, as well as an evaluation system connected to the measurement systems. Also disclosed is a combustion chamber comprising a device and operated by a process according to the invention, and a gas turbine with said combustion chamber.

Abstract: A sensor control device is connected with a plurality of exhaust sensors including an NOx sensor to be disposed around a catalyst, and is constructed such that a plurality of drive control circuits to be connected in a one-to-one relationship with the individual gas sensors are disposed in one casing. The sensor control device is provided with a communication output section that outputs signals through a digital communication line so that the signal transmissions/receptions with an ECU may be executed through the digital communication line. This digital communication line is physically a one-system cable but can transmit and receive signals of a plurality of kinds with predetermined communication protocols.

Abstract: An apparatus for measuring particulate matters includes a particulate matters collecting part 1 that collects particulate matters contained in exhaust gas from an engine 200 by a collecting filter 41 during a predetermined period while the engine 200 is dynamically driven. A second measuring part 22 continuously measures properties indirectly indicating the mass of the particulate matters contained in the exhaust gas during the predetermined period. A correlation calculating part 82 calculates a correlation between the measurement result of the mass of the particulate matters collected by the particulate matters collecting part 1 and a time integration value of the measurement result in the second measuring part 22 during the predetermined period. A converting part 83 converts the continuous measurement data in the second measuring part 22 into a time series variation of the mass of the particulate matters based on the correlation.

Abstract: A compact sensor with which particles floating in the air can be easily detected. A sensor having a microstructure which detects a detection object by contact is used. A microstructure has an opening to be a detection hole corresponding to the size of a detection object, and a pair of electrodes having a bridge structure are provided thereabove or thereunder so as to partially contact with each other.

Abstract: A method for operating a sensor for recording particles in an exhaust gas flow and a device for carrying out the method are provided, in which at least one measure of the exhaust gas flow is ascertained and in which the measure of the exhaust gas flow is taken into consideration in the valuation of the particle sensor signal made available by the particle sensor. The procedure is based on the knowledge that the exhaust gas flow, for instance, the exhaust gas volume flow, has an influence on the particle sensor signal made available by the particle sensor, especially when the measuring effect is based on the depositing of particles on a sensor surface. Using the procedure, a possibly present cross sensitivity of the particle sensor with respect to different exhaust gas flows is taken into consideration, so that the measuring accuracy is increased.

Abstract: The invention concerns a procedure to determine a mass of particles or a particle mass flow in an exhaust gas system of an internal combustion engine, whereby at least one resistive particle sensor is disposed in the exhaust gas system of the internal combustion engine. The measured signal change of the particle sensor is compared with a predicted signal change of the particle sensor ascertained from an engine model. If the measured signal change of the particle sensor and/or the predicted signal change of the particle sensor are corrected while taking into account the influencing variables on the transverse sensitivities of the particle sensor, it is possible when ascertaining the predicted signal change of the particle sensor that a compensation for the transverse sensibilities can result even during dynamic operating point changes of the internal combustion engine, which occur faster than the actuation of the particle sensor.

Abstract: A sensor for detecting particles in a gas flow, in particular soot particles in an exhaust gas flow, includes at least two measuring electrodes, which are positioned on a substrate made of an insulating material. To protect the measuring electrodes, they are covered by a protective layer.

Abstract: A procedure for operating a collecting particle sensor, which is provided with measuring phases, during which particles that are contained in an off-gas stream accumulate on a measuring route, and a device for implementing this procedure are submitted. Protection phases are provided, during which at least one measure for diminishing the accumulation of particles on the measuring route is adopted. The measure according to this invention prevents a decrease of the sensitivity of the particle sensor over a long period of time.

Abstract: A procedure for operating a particle sensor that is arranged downstream after a particle filter, at which an ash contamination can occur, and a device for implementing the procedure, are suggested. A remaining operating time determination determines the remaining operating time of the particle sensor related to an ash contamination. Alternatively or additionally the remaining operating time determination provides a correction signal, with which the sensitivity loss of the particle sensor caused by the ash contamination can be considered.

Abstract: A gas sensing element for detecting a specified gas concentration in measuring gases is disclosed. The gas sensing element has at least a surface layer portion formed with an alumina composite sintered body having a principal component of alumina. The alumina composite sintered body contains alumina particles and dispersion particles, dispersed in a boundary between the alumina particles or in the alumina particles, which have an average particle diameter smaller than that of the alumina particles. The dispersion particles have particle-to-particle distances with an average of 4 ?m or less and a standard deviation of 1.8 or less. The dispersion particles have particle diameters with an average of 0.2 ?m or less and a standard deviation of 0.05 or less.

Abstract: A sensor element for gas sensors for determining the concentration of particles in gas mixtures, especially soot sensors, having at least one measuring device exposed to the gas to be determined, at least one heating element integrated into the sensor element and at least one temperature measurement element integrated into the sensor element, the heating element being situated within the sensor element spatially between the measuring device and the temperature measurement element.

Abstract: An SOF measuring system that can continuously measure SOF and a soot measuring system that can continuously measure soot are connected with an exhaust gas line. The soot measuring system comprises a diluter that selectively dilutes either one of the exhaust gas and standard gas whose hydrocarbon concentration is known with diluent gas and extrudes it. A dilution ratio adjusting device can adjust a dilution ratio of the diluter. A soot detector continuously detects soot in the exhaust gas or the standard gas diluted by the diluter. The SOF measuring system can be connected with the diluter so that an exhaust gas analyzer can measure the hydrocarbon concentration in the standard gas diluted by the diluter.

Abstract: An air-fuel ratio sensor that outputs a sensor signal used for the feedback control of an air-fuel ratio is provided. It is determined whether an element crack is present by applying a reverse voltage to the air-fuel ratio sensor. The value of the sensor signal output from the air-fuel ratio sensor is corrected during a time period “A”. The time period “A” consists of a reverse-voltage application time period in which the reverse voltage is applied, and a return time period “T” after application of the reverse voltage ends. The return time period “T” is set based on sensor impedance correlated with the internal resistance of the air-fuel ratio sensor. The return time period “T” decreases as the sensor impedance decreases.

Abstract: A method for a method for calibrating a system configured to analyze exhaust gas produced by a fluid consuming source is disclosed. The method includes directing a first flow of exhaust gas toward an analyzer that is configured to measure at least one component. The method also includes establishing a first value indicative of a measurement of the at least one component within the first flow of exhaust gas. The method also includes removing a first quantity of fluid from the fluid consuming source and delivering a second quantity of fluid into the first flow of exhaust gas. The second quantity of fluid is a portion of the first quantity of fluid. The method also includes at least partially combusting the first flow of exhaust gas and the first quantity of fluid upstream of the analyzer and establishing a second value indicative of a measurement of the at least one component within the exhaust gas and the at least a portion of the first quantity of fluid.

Abstract: A soot detecting apparatus includes: a high voltage generating unit for generating a high voltage; a discharge sensor which includes a pair of electrodes to be, disposed in an atmosphere to be detected, for causing a spark discharge at a discharge voltage dependent upon soot concentration in the atmosphere when the high voltage is applied across the pair of electrodes; a first detection unit for detecting a first discharge voltage value when the spark discharge occurs in the discharge sensor upon application of the high voltage of a predetermined voltage polarity; a first output unit for determining a first soot concentration value based on the first discharge voltage value; and a changeover unit for converting the predetermined voltage polarity to an opposite voltage polarity for causing reverse spark discharge at the pair of electrodes of the discharge sensor.

Abstract: A device for detecting the amount or concentration of particulate matter in a gas medium comprises a structure for the deposit of solid particles, at least a first and a second electrode associated to the structure, and means for measuring an electric quantity between the first and second electrode. A plurality of cavities is defined in the structure, which act as collectors of solid particles, the structure being arranged so as to induce the accumulation of the particles inside the cavities.

Abstract: The invention relates to a measuring device for measuring aerosols, which measuring device comprises detection means (13), means (41) for conveying a signal from the detection means (13), a first insulation (43), a second insulation (44), and a supporting means (42). The first insulation (43) insulates the medium (41) from the supporting means (42), and the second insulation (44) insulates the detection means (13) from the supporting means (42). Also, the second insulation (44) is designed in such a way that it positions the detection means (13) in a predetermined location.

Abstract: Methods and apparati for measuring entrained gas content. One of the disclosed apparatus embodiments includes a chamber and piping for process fluid, the piping including two different sectors each comprising a density and temperature gauge having a pressure gauge located upstream and a second pressure gauge located downstream, the two sectors being operatively joined together by a pressure-changing device. The pressure measurement feature may be incorporated into the combination density and temperature gauge, eliminating the need for separate pressure gauges. Data generated by this invention reduces measurement error caused by the dissolving or exsolving of gases with changes in pressure of a fluid, while providing instantaneous measurement, through apparatuses that measure system conditions at each of two pressure states within a very short period of time. For instance, in the context of continuously coating a substrate, the method of this invention comprises: a.

Abstract: A cigarette monitoring device capable of monitoring individual smoking behaviour and particularly smoke deliveries and of communicating this and other information to a remote location and/or the consumer. The device comprises a cigarette monitoring means, fluid-flow pressure drop and smoke density detection means, data transmission means, data receiving and processing means, as well as means to display the processed data. Display means of the invention may display information that is of interest to the smoker and may offer a direct sales service to the consumer.

Abstract: A fault detecting apparatus for a gas concentration sensor is provided. The apparatus includes a storage device and a fault detecting circuit. The storage device stores therein fault detectable conditions in which preselected different types of faults of the gas concentration sensor are allowed to be detected, respectively. The fault detecting circuit works to detect a selected one of the faults stored in said storage device. When one of the fault detectable conditions is encountered during operation of the gas concentration sensor, the fault detecting circuit initiates detection of a corresponding one of the faults based on an output of the gas concentration sensor, thereby enabling the fault detecting circuit to identify the type of one of the faults to be detected correctly.

Abstract: A method and system for identifying, visually tracking and recording a moving vehicle exceeding a predetermined level of particulate emissions, the method including the steps of: detecting the particulate emissions of the vehicle at a first detection station; detecting the particulate emissions of the vehicle at a second detection station downstream of the first station; recording information identifying the vehicle if the detected emission of the vehicle at either station exceeds the predetermined level; and comparing the recorded information from both stations and identifying the vehicle if its identity appears in the recorded information for both stations and providing video tracking of the identified vehicle for an extended time period.

Abstract: Improved control of continuous processes that handle liquids. Data generated by this invention is used to control gas contents of liquids within optimum ranges, for instance in paper coating processes and in the manufacture of food products (ketchup), personal care products (shampoo), paints, and in any industry where information on entrained and/or dissolved gases, and related parameters such as true density of and gas solubility in process liquids, is employed to optimize processing. The amount of gas in a liquid is determined by subjecting a mixture of an incompressible liquid sample and a compressible gas to three or more different equilibrium pressure states, measuring the temperature and volume of the mixture at each of the pressure states, determining the changes in volume of the mixture between at least two different pairs of pressure states, and calculating the amount of gas in the liquid sample.

Abstract: The components of cigarette smoke, known until now, do not explain the overwhelming hazardous effects of smoking; this invention describes the isolation, identification and procedures for determination of the structure, properties and assay of a relatively stable major harmful oxidant (cs-oxidant) present in the cigarette smoke, the content of which is about 190±10 ?g per cigarette; the cs-oxidant alone almost quantitatively accounts for the oxidative damage of proteins produced by the aqueous extract of whole cigarette smoke, it is also responsible for the oxidative damage of DNA; since the cs-oxidant is relatively stable, it further explains the deleterious effects of the side stream smoke and passive smoking; a number of chemical compounds/agents including vitamin C have been found to prevent the cs-oxidant induced protein oxidation in vitro.

Abstract: A signal processing apparatus for detecting and displaying the properties of diesel fuel powered compression-ignition engines senses strain pulses in the fuel injection rail structure to perform a variety of testing functions. Among other capabilities, the apparatus permits the user to establish stroboscope timing, to measure engine RPM, to view the relationship between crankshaft position and injection time, and to examine the time-dependent properties of strain pulses on individual fuel injectors in order to evaluate the condition of the diesel engine.

Abstract: An apparatus for real-time measurement of mass, size and number of solid particles of particulate matter in engine exhaust has a catalytic stripper to remove at least about 90% of a volatile fraction of the particulate matter and pass at least about 95% of a solid fraction of the particulate matter, and a micro-dilution tunnel to cool the test medium after passing through the catalytic stripper and prior to passing through a particle sizer and counter system. A method embodying the present invention includes removing a volatile fraction of the particulate matter carried in a sample test stream and comparing the sample after removal of the volatile fraction with a second sample in which the volatile fraction has not been removed. The difference between the two samples represents liquid phase of the volatile fraction of the tested exhaust gas.

Abstract: The components of cigarette smoke, known until now, do not explain the overwhelming hazardous effects of smoking; this invention describes the isolation, identification and procedures for determination of the structure, properties and assay of a relatively stable major harmful oxidant (cs-oxidant) present in the cigarette smoke, the content of which is about 190±10 &mgr;g per cigarette; the cs-oxidant alone almost quantitatively accounts for the oxidative damage of proteins produced by the aqueous extract of whole cigarette smoke, it is also responsible for the oxidative damage of DNA; since the cs-oxidant is relatively stable, it further explains the deleterious effects of the side stream smoke and passive smoking; a number of chemical compounds/agents including vitamin C have been found to prevent the cs-oxidant induced protein oxidation in vitro.

Abstract: Improved control of continuous processes that handle liquids. Data generated by this invention is used to control gas contents of liquids within optimum ranges, for instance in paper coating processes and in the manufacture of food products (ketchup), personal care products (shampoo), paints, and in any industry where information on entrained and/or dissolved gases, and related parameters such as true density of and gas solubility in process liquids, is employed to optimize processing. The amount of gas in a liquid is determined by subjecting a mixture of an incompressible liquid sample and a compressible gas to three or more different equilibrium pressure states, measuring the temperature and volume of the mixture at each of the pressure states, determining the changes in volume of the mixture between at least two different pairs of pressure states, and calculating the amount of gas in the liquid sample.

Abstract: A method and apparatus for aligning the axis of a mirror of a carbon in ash sensor. The method first executes a series of steps that causes a stepper motor connected to an axis of the mirror to move the mirror through a first coarse alignment procedure and then executes a second series of steps that that moves the mirror through a second fine alignment procedure.

Abstract: One embodiment of a particulate sensor system; comprises a first sensing electrode and a second sensing electrode in thermal and electrical communication with a heater wherein the first sensing electrode and the second sensing electrode are disposed on the same side of an electrode substrate. One embodiment of a method for operating a particulate sensor system comprises introducing a gas stream to a sensor; monitoring the resistance between the first sensing electrode and the second sensing electrode, and increasing the temperature of the sensor when the resistance is greater than or equal to a first selected level. One embodiment of a method for operating a filter system comprises exposing a sensor to a pre-selected number of self-regeneration cycles, and increasing the temperature of the filter system.

Abstract: A method and apparatus for calculating the volume fraction of carbon in the fly ash using a carbon in fly ash sensor that has a resonant cavity. The method first determines the volume fraction of ash in the fly ash. The method then determines the real and imaginary components of the dielectric constant of a mixture of pure carbon and pure fly ash, and the transmission factor of a signal from the oscillator in the sensor transmitted through the cavity due to absorption by material in the cavity. The method then determines the volume fraction of carbon in the fly ash by using the volume fraction of ash, the real and imaginary components of the pure mixture dielectric constant, the absorption transmission factor and the length of the cavity, the speed of light and the frequency of the oscillator.