Abstract: A gas sensor including a detection element having a stacked structure configured to detect a specified gas component contained in a gas to be detected. The detection element includes: a sensing portion including one or more solid electrolyte layers containing a first material as a main component and having a first surface and a second surface opposite the first surface; a first portion stacked on the first surface and including one or more first base layers containing a second material as a main component different from the first material; and a second portion stacked on the second surface and including one or more second base layers containing the second material. A total thickness of the one or more second base layers in a stacking direction is not less than 80% but not more than 120% of a total thickness of the one or more first base layers.

Abstract: An initial concentration of the residual concentration of a causative substance contained in an insulating oil is compared with a reference value. The causative substance reacts with a conductor forming a winding of an oil-filled electrical device to generate an electrically conductive compound. The reference value is defined as a value for determining whether a main determinant that determines the lifetime of the oil-filled electrical device is generation of the electrically conductive compound or degradation of insulating paper. Based on the initial concentration of the causative substance and the reference value, the lifetime of the oil-filled electrical device is assessed.

Abstract: A gas sensor comprises a gas sensing element, a housing for the gas sensing element, and an element cover secured to an axial end of the housing and composed of an inner cover covering part of the gas sensing element and an outer cover disposed outside the inner cover. The outer cover comprise an approximately cylindrical side wall body, a bottom body integral with the side wall body, and a guide having first and second ends, the first end being secured to the side wall body and the second end being separated from the side wall body and located to provide a side opening between the second end and the side wall body. The side opening introduces a gas thereinto. A discharge opening is formed through the bottom body. The second end is recessed inward in the outer cover and is closer to the bottom body than the first end.

Abstract: A gas sensor (1) includes at least a sensor element (12) which measures the concentration of a specific gas component, a housing (13) which accommodates the sensor element (12), and a base portion (21) which is attached to the housing and is formed of resin. The base portion includes a first base portion (22) which is a portion of the base portion located on the side toward the housing and which is molded integrally with the housing, and a second base portion (23) which is molded separately from the first base portion, which is a portion of the base portion located opposite the housing, and which has a connector portion (23c) in which a plurality of terminals (26) electrically connected to the sensor element are disposed such that they extend in a direction intersecting the insertion direction of the sensor element.

Abstract: It is an object of the present invention to provide a gas concentration detection apparatus that is capable of forming an accurate activity judgment when a gas concentration detection cell begins to detect gas concentration with high accuracy. When warm-up begins at time t0 in a NOx concentration detection apparatus that achieves NOx concentration detection with a NOx sensor cell after excess oxygen is discharged by an oxygen pump cell, a NOx sensor cell output begins to rise at time t1. Subsequently, at time t2, an oxygen pump cell output begins to rise. An inflection point appearing in the NOx sensor cell output is then located. At time t5 at which the inflection point appears, an activity judgment about the NOx sensor cell is formed.

Abstract: A method recognizes at least one feature of fuel in an internal-combustion engine (1). The method comprises steps of: detecting, by at least one sensor, intensity (S) of vibrations generated by the internal-combustion engine (1) within a measurement-time window; determining a value of at least one synthetic index (I) by processing the intensity (S) of the vibrations generated by the internal-combustion engine (1) within the measurement-time window; comparing a synthetic index (I) with at least one predetermined comparison quantity (TH); and recognizing the feature of the fuel as a function of the comparison between the synthetic index (I) and comparison quantity (TH).

Abstract: A system for detecting pollution by a poisonous material for an air exhauster of a vehicle may include a temperature sensor provided to the flow line of an exhaust gas and having a catalyst material that causes an exothermic reaction with a pollution material in the exhaust gas, and a controller which stores a standard temperature value of the temperature sensor and operates in such a manner that the exhaust gas may be heated under control of an engine control unit when the temperature value drops by a predetermined amount from the standard temperature value, and that the catalyst material may be determined to have deteriorated when a measured temperature value after heating may be less than the standard temperature value, so that the standard temperature value may be replaced with the measured temperature value, and to a detection method using the same.

Abstract: Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (110, 120), wherein the exhaust gas to be measured is supplied to the first measuring chamber (110) and an oxygen concentration is set by means of a first oxygen ion pump current (IP1), wherein the second measuring chamber (120) is connected to said first measuring chamber (110) and wherein both measuring chambers are disposed in a solid electrolyte, the oxygen content in the second measuring chamber (120) is determined; the oxygen content is additionally determined by a separate device; the two values characterizing the oxygen concentration are compared and a defective sensor is then suggested if the oxygen concentration value determined in the second measuring chamber (120) deviates from the oxygen concentration value determined by the separate sensor device by a predeterminable magnitude.

Abstract: The present invention provides a class of sensors prepared from regions of conducting organic materials and conducting materials that show an increase sensitivity detection limit for amines. The present class of sensors have applications in the detection of spoiled food products and in testing for diseases, such as cholera and lung cancer, which have amines as biomarkers.

Abstract: There is provided a control device for a gas sensor. The gas sensor is formed with first and second oxygen pumping cells to define first and second measurement chambers. Under the control of the sensor control device, the first and second oxygen pumping cells effect oxygen pumping actions against the first and second measurement chambers, respectively. The sensor control device is configured to detect currents through the first and second oxygen pumping cells, calculate a correction coefficient by comparison of a detection value of the first oxygen pumping cell current at a known oxygen concentration period with a previously stored reference value, correct the first oxygen pumping cell current by the correction coefficient and determine the concentration of nitrogen oxide in the gas under measurement based on the corrected first oxygen pumping cell current and the detected second oxygen pumping cell current.

Abstract: Internal combustion engines which are operated using ethanol exhibit an improved capability for lean-burn running. The lean-burn running limit with a higher ethanol proportion is displaced in the direction of lean. This link between the lean-burn running limit and the ethanol proportion of the fuel is used to determine the ethanol proportion. To determine the lean-burn running limit, a fuel quantity is injected into a cylinder in the operating range of the overrun fuel cut-off, with which fuel quantity no combustion of the air/fuel mixture occurs, and the fuel quantity is increased continuously until combustion occurs; the smooth running of the engine is monitored for this cylinder and the lean-burn running limit is detected as reached if the smooth running exceeds a predefined threshold value. The ethanol proportion is then deduced from the increase in the injected fuel quantity which is required to reach the lean-burn running limit.

Abstract: A method of monitoring a sensor of an exhaust system is provided. The method includes evaluating humidity of air entering the exhaust system; and monitoring operation of a sensor in the exhaust system based on the humidity.

Abstract: A device for measuring a particulate concentration in motor vehicle exhaust gases, has a measuring chamber, which is able to be filled up with a gas-particulate mixture that is to be measured, at least one light source and at least one light sensor. The light sensor detects light that has been scattered by particulates present in the gas-particulate mixture. An exhaust gas supply device is developed to supply exhaust gas, that is to be measured, to the measuring chamber. A null gas low in particulates is able to be supplied from a null gas source to the measuring chamber. A switching element, which is situated between the exhaust gas supply device and the measuring chamber, is suitable for admitting or forestalling the supply of exhaust gas into the measuring chamber on an optional basis.

Abstract: A method and apparatus for controlling a multi-gas sensor, including an NOX sensor section and an ammonia sensor section. The NOX sensor section includes a first pumping cell adapted to pump oxygen into or out of a gas under measurement introduced into a first measurement chamber, and a second pumping cell communicating with the first measurement chamber and configured such that a second pumping current Ip2 corresponds to an NOX concentration of the gas under measurement. Oxygen concentration is calculated on the basis of a first pumping current flowing through the first pumping cell, and a corrected ammonia concentration is calculated on the basis of the oxygen concentration and the ammonia concentration output of the ammonia sensor section.

Abstract: A detector for detecting sulfur components having a storage portion for storing SOX and NOX in the exhaust gas passing through an exhaust passage and a temperature sensor for measuring a temperature of the storage portion. The detector includes a heater for heating the storage portion and determines the current heat capacity (C) of the storage portion on the basis of an increase in (T2?T1) the temperature of the storage portion measured by the temperature sensor and a quantity of heat (QH) generated by the heater when the heater heats the storage portion.

Abstract: A gas sensor includes a substantially cylindrical metal shell; a laminated sensor element held within the metal shell, and including a plate-shaped solid electrolyte layer extending in a longitudinal direction; an electrode portion provided on the solid electrolyte layer; an insulating layer; and a lead portion connected with the electrode portion, extending in the longitudinal direction, and having a front end portion laminated on the solid electrolyte layer, and a rear end portion laminated through the insulating layer on the solid electrolyte layer. The insulating layer has an end portion over and across which the lead portion extends, and which has a recessed shape, a raised shape, or a recessed and raised shape in the longitudinal direction as viewed in the lamination direction.

Abstract: A gas sensor element is composed of a sensor section, a heater section, and a porous protective layer. The sensor section is composed of a solid electrolyte layer and a pair of electrodes. The heater section heats the sensor section to activate it. The porous protective layer covers surfaces of the sensor section and the heater section of the gas sensor element in a gas sensor which is exposed to a target detection gas to be detected. The porous protective layer is made of a mixture of hydrophobic heat resisting particles having a contact angle of not less than 75° to a drop of water, and the hydrophilic heat resisting particles having a contact angle not more than 30° to a drop of water. A gas sensor equipped with the above gas sensor element is also disclosed.

Abstract: To achieve gas detection in a precise and reliable way, but at the same time without consuming too much energy, a gas detection system is provided which generally comprises a pair of two different gas detectors. The first detector (DLP) is active continuously and sense substantially for an unspecific change in the local gas mixture. As a reaction upon the change, the second detector (DHP) of the pair is activated. This detector (DHP) performs the determination of the concentration of a specific gas or several specific gasses. The second detector (DHP) may be of a type which consumes more power, but will be active for a short period of time before returning to an inactive state where only the first detector (DLP) is active. The first detector (DLP) however is of a type using little power.

Abstract: A thermal shock protected gas sensor includes a body, a ceramic sensor element positioned in the body, and a protection tube. Thermal shock protection against liquid water impingement on the hot ceramic sensor element is provided by a sleeve of ceramic fiber woven fabric positioned between the ceramic sensor element and the protection tube, and an annular gap between the ceramic sensor element and the protection tube on at least one side of the sleeve. Alternately, thermal shock protection is provided by a porous monolithic cast ceramic layer between the ceramic sensor element and the protection tube.

Abstract: An automated testing apparatus for remotely performing a testing sequence to ensure that a sensor is functioning. The apparatus can include a detector, a storage container, a burst valve in fluid communication with the storage container, a testing control module in communication with the storage container and the burst valve, and a remote user interface remotely located from the detector. Preferably, the automated testing apparatus can simplify the testing procedure, increase the frequency of sensor testings, thereby notifying operations of sensor failures in a more timely fashion without the need for an operator to check the sensor locally.

Abstract: A PM amount detecting apparatus having a PM sensor installed in a sensor case into which a part of exhaust gas of an internal combustion engine allowed to flow through an exhaust gas passage is intaken. The sensor case has a structure which lowers a flow rate of the exhaust gas therein to such an extent that PM is capable of performing thermal phoresis, and a structure which generates therein such a temperature difference that PM is guided to the PM sensor in accordance with the thermal phoresis.

Abstract: A gas sensor including a pump electrode and a method for manufacturing a conductive paste for forming the pump electrode. When the pump electrode constituting an electrochemical pump cell for adjusting an oxygen partial pressure inside a gas sensor to measure a concentration of a gas component in a measurement gas by a current-limiting method is formed of a cermet of a noble metal and an oxide having oxygen ion conductivity, the noble metal contains a first noble metal having a catalytic activity, and a second noble metal having a catalytic activity suppressing ability to suppress the catalytic activity of the first noble metal with respect to an oxide gas except for oxygen, and an abundance ratio of the second noble metal with respect to the first noble metal in a particle surface of the first noble metal existing in the pump electrode is to be 0.01 to 0.3.

Abstract: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.

Abstract: A gas sensor apparatus and method of forming the same generally includes a gas sensor element comprising a heater and a plurality of electrodes. A ceramic substrate can be provided for supporting the electrodes on one side of the ceramic substrate and the heater on the opposite side of the ceramic substrate. The gas sensor element is preferably embedded in the ceramic substrate. The ceramic substrate also possesses a substantially circular shape in order to prevent a breakage of the gas sensor element, avoid thermal loss, and permit the gas sensor apparatus to withstand mechanical shock and high vibrations while occupying a minimal package space.

Abstract: Systems and methods for monitoring a fuel reformer which reforms ethanol into a reformate gas comprising H2, CO, and CH4 for fueling an engine are provided. Degradation of the fuel reformer may be indicated based on an amount of ethanol injected into the fuel reformer and an amount of at least one of H2, CO, and CH4 produced by the fuel reformer.

Abstract: A ceramic heater including: a ceramic substrate having a heater element which generates heat when energized and an electrode pad disposed on a surface of the ceramic substrate, the electrode pad being electrically connected to the heater element, and a connection terminal electrically connected to the electrode pad through a braze part bonded to the electrode pad, the braze part being made of an alloy of copper and gold and the connection terminal being made of nickel or a nickel alloy, wherein a first region of the braze part within a distance of 15 ?m from a contact face between the braze part and the connection terminal has a gold content of more than 6 wt % and less than 10 wt %.

Abstract: Disclosed herein are sampling systems and sampling methods for regulating the provision of sample gases to downstream analytical equipment, such as an exhaust bench for analyzing exhaust gases emitted from an internal combustion engine. In some embodiments, the described systems and methods can enable accurate measurements to be taken from a source of gaseous samples, regardless of the gaseous sample inlet pressure.

Abstract: A system and/or method for quantifying the presence of one or more components in vehicle exhaust, and more particularly to a non-contact, sampling system and method for quantifying the presence of one or more components in exhaust emissions of commercial and/or heavy-duty vehicles that emit exhaust at an elevated level, under actual operating conditions.

Abstract: A gas sensor includes an inner electrode formed on an inner surface of a base body. The inner electrode has an inner sensing portion formed in a gas contact inner region such that the inner sensing portion is located on the whole of a heat-facing area of the gas contact inner region facing a heating portion in a radial direction of the base body, a terminal contact portion formed in a rear end region such that the terminal contact portion is located in at least a part of the rear end region in a circumferential direction of the base body and a lead portion formed only on a part of the inner surface of the base body in the circumferential direction of the base body so as to connect the inner sensing portion and the terminal contact portion to each other.

Abstract: A method for detecting soot in a gas is disclosed. The method may include applying a voltage pulse to electrodes exposed to the gas, wherein the voltage pulse has a higher voltage amplitude than a breakdown voltage of the gas. The method may also include detecting breakdown of the gas, and determining a time to breakdown of the gas since application of the voltage pulse. The method may additionally include determining a concentration of particulate matter entrained in the gas based on the time to breakdown.

Abstract: A system and method of detecting a degraded head gasket in an engine. The detection of a combustible product in the coolant of a cooling system for the engine is used to indicate a degraded head gasket. The combustible product detection is facilitated by deaerating the engine coolant in a dearating tank. Gases extracted from the coolant in the deaerating tank are sampled and detected by a combustible product sensor, which outputs a signal if the combustible product is detected.

Abstract: A method for analyzing the exhaust gas of internal combustion engines provides for the cooling of the exhaust gas before analysis, the determination of the concentration of at least two different exhaust gas components in at least two separate analysis stages or the determination of the concentration of a single exhaust gas component with at least two different cooling stages. In order to achieve a higher measuring accuracy, at least one first cooling is carried out before a first analysis stage and at least one second cooling is carried out at a lower temperature than that of the first cooling before at least one further analysis stage.

Abstract: A sensor assembly to measure particulate matter is described. The sensor assembly includes a voltage source, a sensor electrode, a grounded assembly, an integration capacitor, and a current meter. The sensor electrode is coupled to the voltage source to receive a voltage. The sensor electrode is disposed within a directed and controlled exhaust flow within the sensor assembly to facilitate particle agglomeration into particulate matter structures at a surface of the sensor electrode. The grounded assembly is coupled to a ground reference and disposed at a distance from the sensor electrode. The integration capacitor is coupled to a negative side of the voltage source. The integration capacitor is configured to integrate in time current pulses from charge transfers from the sensor electrode of the particulate matter structures.

Abstract: A particulate matter sensor includes a ceramic rod, a first metal layer deposited on the ceramic rod, a ceramic layer deposited on the first metal layer, and a second metal layer deposited on the ceramic layer. The first metal layer serves as a source electrode, and the second metal layer serves as a detection electrode. In another embodiment, a particulate matter sensor includes a metal rod, a ceramic sheet deposited or wrapped around the ceramic rod, and a metal layer deposited on the ceramic layer or sheet. The metal rod serves as a source electrode, and the second metal layer serves as a detection electrode.

Abstract: Methods, software codes, and devices for determining an emission flow rate of one or more CO2 equivalent gases from an exhaust system of an internal combustion engine of a vehicle and a method of determining a vehicle efficiency factor of the vehicle are provided. The vehicle efficiency factor is compared in real time to the corresponding point on a vehicle efficiency map based on at least one of current vehicle conditions, driving conditions, environmental conditions, and energy flow visualization data to derive a driver efficiency factor.

Abstract: An emission test system may include at least one controller configured to determine, directly or indirectly, a quantity of diluted exhaust sample in a container at the completion of an emissions test, and to cause additional diluent gas to be added to the container based on the determined quantity.

Abstract: A method and a particle sensor (5) are provided for measuring particles, especially soot particles. The particles to be detected accumulate in a measuring region (10) of the particle sensor (5). The particles located in the gas stream (55) or the particles already accumulated in the measuring region (10) are burned by a combustion device (15), the combustion being controlled via a control signal from a control unit (20), which is electrically connected to a measuring device (25), in such a way that the quantity of the particles adhering in the measuring region (10) remains constant. The physical variable of the combustion device (15), which leads to the controlled combustion of the particles, is drawn upon as the signal amplitude of the particle sensor (5).

Abstract: A device for sensing a gas comprises a plastics housing (106, 107) moulded in situ around at least one portion of a conducting lead frame (100), the housing defining an enclosure (113) and being provided with means for enabling gas flow into the enclosure. A gas sensitive element (114) within the enclosure (113) is mounted to the conducting lead frame (100). The conducting lead frame (100) comprises connection leads which are accessible through, and at least partially encapsulated by, the wall of the housing.

Abstract: A gas sensor for measuring NOx concentration in measurement gas based on sensor output depending on an amount of the detected oxygen includes an oxygen concentration control part for controlling oxygen concentration in the measurement gas. The oxygen concentration control part allows a control of oxygen concentration in the measurement gas to set at a designated value even after being mounted on an automobile, so that dependency of the sensor output with respect to oxygen concentration can be quantitatively detected. The sensor output for detecting NOx concentration is corrected by estimating an amount of a change accompanying the sensitivity degradation of the sensor output with respect to NOx concentration on the basis of a difference between oxygen output characteristics of the sensor output of an actually-used sensor and oxygen output characteristics of a sensor in the initial state, and correcting the sensor output in accordance with the amount of the change.

Abstract: The present detector for detecting sulfur components includes a storage portion for storing SOx and NOx in the exhaust gas passing through an exhaust passage, in which the more an amount of stored SOx increases, the more an amount of NOx that can be stored decreases, estimates the amount of stored SOx on the basis of an amount of NOx stored in the storage portion, and detects an integrated amount of SOx passing through the exhaust passage during a given period or an value on the basis of the integrated amount. In the present detector, the estimating of the amount of stored SOx for detecting the integrated amount of SOx or the value on the basis of the integrated amount is prohibited when a current amount of NOx that can be stored is not stored in the storage portion.

Abstract: A time-course change (dM/dt) in the mass of air in an intake passage downstream of a throttle value is estimated through application of a mass conservation law to the air in the passage. A time-course change dTm/dt in the temperature of the air in the passage is estimated through application of an energy conservation law to the air in the passage. The pressure of the air in the passage is estimated on the basis of the mass of the air in the passage obtained through integration of dM/dt with respect to time, the intake air temperature obtained through integration of dTm/dt with respect to time, and a state equation applied to the air in the passage. Only the state equation includes a term regarding the volume of the passage. Therefore, it is possible to easily identify the volume while monitoring only a change in the intake air pressure.

Abstract: A sensor including a tubular casing having an open rear end; and a first elastic member having a through hole so as to introduce ambient air into the casing and disposed so as to block the rear end opening of the casing.

Abstract: A particle sensor arranged in an exhaust duct such that particles from the exhaust-gas flow accumulate on and/or between at least two sensor electrodes when a voltage greater than a limit voltage is applied between the two sensor electrodes and substantially no particles accumulate if the voltage is lower than the limit voltage. During a first time period, a first voltage greater than the limit voltage is applied between the sensor electrodes. During a second time period, a second voltage, lower than the limit voltage, is applied between the sensor electrodes, and/or the particle sensor is heated to a predefined temperature, such that substantially no particles accumulate on and/or between the at least two sensor electrodes. Following the second time period, a third voltage greater than the limit voltage is applied between the sensor electrodes.

Abstract: Provided are an environmental gas sensor and a method of manufacturing the same. The environmental gas sensor includes an insulating substrate, metal electrodes formed on the insulating substrate, and a sensing layer in which different kinds of nanofibers are arranged perpendicular to each other on the metal electrodes. Thus, the environmental gas sensor can simultaneously sense two kinds of gases.

Abstract: A method of offsetting carbon dioxide (CO2) emissions includes the steps of capturing CO2 emissions data from a vehicle, transmitting the emissions data to a data collection unit, which then stores collected CO2 data and prepares a CO2 emission report. The CO2 emission report is used in preparing a customized CO2 offsetting package, which is selected by a vehicle owner. The selected CO2 offsetting package offsets the CO2 emissions through purchased credits, which neutralize the CO2 released from the vehicle. The owner of the package is given a visual indicator exhibiting that the vehicle is currently carbon neutral.

Abstract: A method for fault identification of gas sensors exposed to a gas mixture is disclosed for gas sensors having an output that depends on concentrations of two gas species in the gas mixture. The method includes receiving output signals from two such sensors, processing the output signals in a controller that implements a model of the sensors so as to identify a fault in the first gas sensor or the second gas sensor; and providing an indication of any identified faults.

Abstract: Methods, processes and compositions are provided for a visual or chemochromic hydrogen-detector with variable or tunable reversible color change. The working temperature range for the hydrogen detector is from minus 100° C. to plus 500° C. A hydrogen-sensitive pigment, including, but not limited to, oxides, hydroxides and polyoxo-compounds of tungsten, molybdenum, vanadium, chromium and combinations thereof, is combined with nano-sized metal activator particles and preferably, coated on a porous or woven substrate. In the presence of hydrogen, the composition rapidly changes its color from white or light-gray or light-tan to dark gray, navy-blue or black depending on the exposure time and hydrogen concentration in the medium. After hydrogen exposure ceases, the original color of the hydrogen-sensitive pigment is restored, and the visual hydrogen detector can be used repeatedly.

Abstract: A control device for a gas sensor is configured to: receive a mode command to specify one of a plurality of sensor energization modes including at least a gas concentration detection mode, a protection mode and a pre-energization mode; switch a sensor element of the gas sensor into the one of the plurality of sensor energization modes according to the mode command; judge satisfaction of a certain condition where the mode command is to specify the gas concentration detection mode and the sensor element is in any of the plurality of sensor energization modes other than the pre-energization mode at the time of receipt of the mode command; and prohibit the sensor element from switching over to the gas concentration detection mode when the certain condition is satisfied.

Abstract: The present invention provides a method of controlling engine performance that includes obtaining at least one optical wavelength-dependent measurement from at least one combustion event in at least one combustion chamber. The method further includes analyzing the optical wavelength-dependent measurement for determining adjustments to the at least one combustion event. Additionally, the method includes adjusting the at least one combustion event or at least a next combustion event by changing at least one physical parameter, at least one constituent parameter, or at least one physical parameter and at least one constituent parameter to control the engine performance. The engine can include steady-flow engines or periodic flow engines, and the engine performance can be selected by an engine user.

Abstract: Testing of engine particulate matter production during a transient is made more accurate by selecting an appropriate sized opening for a test probe of the sampling system located in the exhaust line upstream from a particulate trap. By examining the pressure signature at the test probe location and utilizing that information in conjunction with a desired volumetric flow rate into the sampling system, a flow opening size for the test probe can be selected that reduces potential oversampling which may be otherwise induced due to the back pressure increases in the exhaust line caused by the presence of the particulate trap. The flow opening into the test probe of the sampling system behaves relative unrestricted when pressure differentials at the test probe location are relatively low, such as during steady state operating conditions, but restricts flow into the sampling system when pressure differentials are relatively high, such as at a pressure during a transient event.